PubTalk-11/2021: Busting Myths About One of Largest Volcanic Systems

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Busting Myths About One of the Largest Volcanic Systems in the World - The Top 10 Misconceptions about Yellowstone Volcanism

By Michael Poland, USGS Scientist-in-charge, Yellowstone Volcano Observatory

  • Contrary to popular belief, Yellowstone is not "overdue" for eruption. Volcanoes don't work that way.
  • Yellowstone experiences thousands of earthquakes every year, but these are not a sign of the volcano getting ready to erupt.
  • Despite its reputation, most eruptions from Yellowstone are lava flows, not massive explosions.

November 18th, 2021 at 7:00PM (PST)


Date Taken:

Length: 01:25:28

Location Taken: WY, US


Hello and thank you for joining us

for this month. Public lecture.

My name is Amelia and I will be

your host and moderator today.

As usual, we have some announcements.

First tonight's lecture will be the

last one we have for the calendar year,

starting in January 2022 will be

back with a brand new start time,

which will be at 6:00 PM Pacific

Time and we will have a whole new

set of lectures and amazing USG

USGS science for you to enjoy,

so make sure you mark your calendars for

January 27th at 6:00 PM Pacific Time to

USGS research scientist Thomas Edwards.

Will give us this lecture tentatively

titled species here species,

their species, species everywhere.

I hope you can come back in the

new Year and join us.

Now for those of you who are joining us

for the first time and you're watching

through the desktop version and need to

find the closed captions for this talk,

they are located at the bottom

right hand corner of the screen.

It can click on the closed captions

icon with the two letter CS.

And lastly,

toward the end of the lecture we

will open it up to the Q&A session.

Does it make your question just click

on the question Mark Icon located on the

upper right hand corner of your screen?

We will do our best to get

to your questions tonight,

but please be aware that we might not

be able to get to every single one,

but we will certainly try.

And now it's time to introduce

you to our speaker.

Today we have with us is

Doctor Michael Poland.

Mike is a research geophysicist with

the USGS and the current scientist in

charge of Yellowstone Volcano Observatory.

His area of expertise is volcano

geodesy which is the study of surface

deformation and gravity fields

associated with volcanic activity.

He obtained his Baxter's degree

from UC Davis and his PhD from

Arizona State University and he

has served at both Cascades.

And Hawaiian volcano observatories.

Without further ado,

I'm going to pass it over to Mike,

who will be talking about busting

myths about one of the largest

volcanic systems in the world.

The top ten misconceptions about

Yellowstone volcanism Mike,

thank you for being here.

I will now hand it off to you.

Thanks very much Amelia.

It's pleasure to be here tonight

and thanks everyone for joining us.

It's it's really fun to be able to do this.

I'm sorry we can't do it in person,

but I think we can still have some some

fun tonight with this with this topic.

So I started this job with the

Yellowstone Volcano Observatory four

years ago and it became apparent

really quickly that there are some big

misconceptions about Yellowstone out there.

This title slide sort of shows

one of the bigger ones, you know.

I think what a lot of people think

is that Yellowstone is.

Overdue to erupt in when it blows

it's going to

kill us all and that's a couple of

misconceptions right there so I

thought about a lot of the questions

I've gotten over email and a lot of

the conversations I had when I was in

the park working and wanted to bring

some of those top ten misconceptions

to lighten and bust him down.

So that's we're going to do here tonight.

Talk about some of these misconceptions

and I think actually the answers

are far more interesting than

the misconceptions itself.

Yellowstone is a magical place.

It's it's not called Wonderland

for nothing and and the the truth

of the geology of the place.

Is far more interesting than any of

the mythology's that are out there.

I'd like to start with a sort

of a zero order misconception,

which is also sort of an acknowledgement.

There's a lot of folks that think that

the USGS is the Yellowstone Volcano

Observatory Yvo, but that's not true.

In fact, Yvo is a consortium of

nine different institutions.

It's not just the USGS,

but it's also the group called Navco.

Navco monitors ground deformation

throughout the United States.

It's Montana State University.

And the University of Wyoming and

the University of Utah, Utah.

Does all of these seismic monitoring in the

park and it's the National Park Service,

of course.

And then it's the state geologic

surveys of Montana,

Idaho and Wyoming,

and I've been really privileged to work with

great scientists at all these institutions.

They've taught me a tremendous

amount and I'm really in their debt.

Or we all work together.

We collaborate to try to understand

how Yellowstone works,

and then communicate that information

to the public,

especially when it relates to hazards.

So why video is very much a

collaboration between many,

many different institutions.

And many, many really excellent scientists.


so let's dive right into misconception.

#1 Yellowstone is a super volcano.

Now this is not perhaps as much of a

misconception as it is a rant on my part.

I apologize for that,

but I'm giving the talk right

so I get to set the rules.

I don't like this word.

This supervolcano word.

I'm not a fan at all,

I I it's the S word to me and I I

try my best not to ever use it.

I think it's got a lot of problems

which I'll get into shortly and I

think there's other things we can say

that are more instructive about what

Yellowstone and volcanoes like it are.

But before I dive into why

I just like it so much.

Suck a little bit about the history.

Of the term,

it actually was not introduced

initially to talk about big

volcanoes like Yellowstone.

The first use was right here.

This is the three sisters area

of Central Oregon.

In the 1920s there was a geologist

that mapped the area and he

thought all of these areas.

All of these volcanoes might be

a single large volcanic system.

And then in the 1940s

another professor,

how Williams came through.

He was the one that first worked

out the geology of Crater Lake.

And he said, no, this is.

These are all separate volcanic

systems in a book that he wrote,

and in the review of that

book the reviewer said,

this area is definitely not

some sort of super volcano.

So that was the first time to our

knowledge that this term was really used.

But then it sort of fell into to

this use the term that was used a bit

more frequently was super eruption.

And that's an eruption that is

meant to suggest a certain size.

Generally over 1000 cubic kilometres of

material is ejected in a super eruption.

Really epically large eruptions,

and to give an idea of just how big that is,

let's look at some past eruptions

of different sizes and see how they

scale so this Lassen peak 1915.

That was a very small eruption last

in California might be represented

by this little blue dot right here.

.005 cubic kilometers, so quite small.

Order of magnitude bigger than that.

This is grimsvotn,

which is a volcano in Iceland,

and that erupted in 2004.

This is not the eruption that

closed air traffic in Europe.

This was a much smaller eruption,

but it still melted.

A lot of glacial ice resulted

in some flooding.

It was it was significant.

We go up another order of magnitude

and we get to one that probably most

of you know Mount Saint Helens,

1980 epically big eruption.

But you can probably see from

the size of the dot right here.

The green dot that we have a long way to go.

As impressive as that was.

That eruption just didn't

release that much volume.

If we go up another order of

magnitude now we're getting to some

really big ones Pinatubo in 1991,

a devastating eruption,

and it actually resulted in

a change in global climate.

It caused a small degree of

cooling for a year or two.

Even bigger than that,

the largest eruption of the 20th century,

this was novarupta in Alaska,

Katmai National Park in 1912,

thirteen cubic kilometres of material.

It formed what we call now

the valley of 10,000 smokes.

There's so much ash that was

poured into these valleys.

It was steaming for years afterwards.

Even bigger than over up to now we're

getting into the real big ones.

And this is one of the first

Yellowstone eruptions on our list.

The Mesa falls eruption.

It occurred 1.3 million years ago

and it was 280 cubic kilometres,

but still not a super eruption were

still quite a bit smaller than that.

Long Valley called there now.

This is an Eastern California.

760,000 years ago 650 cubic

kilometers material.

So still not really a super eruption

if we're defining it using this

somewhat arbitrary 1000 cubic kilometers.


the most recent huge Yellowstone

eruption 631,000 years ago.

That's 1000 cubic kilometers.

This is the first super eruption

in our list right

here. There's another Yellowstone

eruption that was even bigger.

This was two point 1,000,000 years ago.

It was two and a half times bigger

than the Yellowstone eruption

that occurred more recently.

That's now at the core of

Yellowstone National Park,

and we can even go one step bigger than that.

This was that Oba eruption 74,000 years ago.

So relatively recently it was over five

times bigger than Yellowstone's most

recent large called Terraforming Blast.

So these last three here.

These are the Super eruptions.

These are what's referred

to as super options,

and so the name kind of super volcano.

Derived from this super eruption super

eruption give you a super volcano but

it really took on a life of its own when

some movies and documentaries came out.

Of course, around 2005 is when they

really started hitting the screen.

Super volcano movies.

I love this.

A true story of a global disaster.

It just hasn't happened yet, or supervolcano.

It's under Yellowstone and it's overdue.

Well, there's a misconception we're

going to come back to right there,

and it's not really under Yellowstone.

It is Yellowstone and a whole

series of these things and they.

They really just drive me nuts.

That word,

I think is is just so misrepresentative

of the actual process that's going on.

So I told you I I try to explain why

I didn't like this turn, but one is.

I think it's kind of trite.

It's silly, right?

You put super in front of everything.

They really mean anything.

It's like putting Uber in front

of everything you, Uber.

Uber need Uber delicious.

In fact,

the Oxford Dictionary I found

this online said that the rate of

using super has gone up by a huge

amount over the last few years,

which I think just emphasizes

how silly this is.

I think it's also misapplied.

This is a satellite image of

campy flegrei caldara in Italy.

Many people might know this is Italy's

supervolcano or Europe Super Bowl camp,

but it's never had an eruption

of 1000 cubic kilometers.

So how can it be a super volcano if

it's never had a super eruption?


that term is just thrown around

I I don't like it.

I think it's it's misapplied in many cases.

And finally,

I think it's very misleading

when you say super volcano you

think this thing only blows up.

It only has huge explosions,

and that's not true at all.

All of these large systems.

It's much more common to have smaller

eruptions, and in fact, in Yellowstone,

since the last big huge explosion,

there have been about two dozen lava

flows shown here in all these pink colors.

The caldera is this green outline,

but all of these pink colors are

lava flows that have happened.

Just over the last few 100,000 years,

so I think it's right it's misapplied.

It's misleading.

I don't like it.

I think instead we ought to

say Caldara system.

This is Long Valley caldera here,

and it sort of exemplifies

what we're talking about.

It belong Valley hasn't had a super eruption,

but it's very similar to Yellowstone

in many ways, the most commonly

has these lava flow eruptions.

The big eruptions are are once once

in a in a few 100,000 years or so.

Once in a few million years.

The same is true of places like camping,

food, Gray, and.

Fires call there in New Mexico,

so I think this is a better,

more descriptive way of describing these

sorts of systems rather than relying on

some silly word that is attached to a

number that may not even really apply.

So I'm going to try not to

use the S word instead.

Let's call these things called Aerosystems,

so opening rant and misconception one,

but it leads us right into misconception.

#2 Yellowstone is overdue.

No, it's not not overdue one.

The math doesn't work. Not that way,

and two that's not the way volcanoes work.

Uhm? And incidentally, as a bit of inside.

How many if we were in person,

I'd probably ask you to raise your hands.

How many of you have heard Yellowstone

described as a powder keg, right?

Or as a ticking time bomb?

And incidentally,

that term drives me nuts as well.

Ticking time. Isn't that a bit redundant?

Don't all time bombs tick?

Why not just call it a ticking

bomb or a time bomb?

It's it's ludicrous.

It's ridiculous.

This is not the way Yellowstone works.

Where did it come about the?

Why do people think that Yellowstone

erupts every 600,000 years?

This is the most common thing you'll hear it.

Yellowstone erupts every 600,000

years and the last time it

erupted was 631,000 years ago.

So we're 31,000 years overdue.


not that way at all on this

geologic map right here.

I've got the three most recent big explosive

eruptions of Yellowstone outlined in pink,

or rather in purple,

is the Huckleberry Ridge caldera

that formed 2.1 million years ago.

It's the biggest.

Of the Yellowstone system.

1.3 million years ago.

Henry's Fork caldera, right,

here off to the West of Yellowstone

National Park.

And then finally, 631,000 years ago,

there's where you get

Yellowstone called there,

which is pretty much most of

Yellowstone National Park.

Now if you look at the

interval between those,

it's actually 725,000 years.

But that's based on two intervals.

I mean,

it's sort of a meaningless average.

It's really pretty ridiculous

to base anything on this,

so the average recurrence

it's not 600,000 years.

That's completely made up by

people trying to get mouse clicks

on documentaries and whatever.

The number is much larger than that.

We'd still have 100,000 years ago,

but that's not really the

way volcanoes work anyway,

and it's based on just a couple of numbers.

Now the Yellowstone system is

a lot more than just the last

three big explosions.

We can trace calderas

back in time all the way

to Northern Nevada,

and that's because Yellowstone is a hot spot.

It's a zone of melting that's

relatively stationary within the Earth,

and Earth's tectonic plates are

moving across the top of that,

and so the hot spot is sort

of burning through that plate.

Kind of like a blowtorch,

and that plate is moving along,

so we have this trail of cold air.

As you can see.

Before the Ellison system,

they called their system that was active

was six to four million years ago.

So if we were to add that in there,

we couldn't even longer recurrence interval.

And in fact,

if you look at just the Super eruptions,

the big ones 1000 cubic kilometres,

they've actually been longer between

those kinds of eruptions over time.

So it's almost as if the

Yellowstone system is losing steam.

But this whole idea of intervals

and being due and overdue.

That's not how volcanoes work anyway.

Volcanoes will erupt when

there is a sufficient supply.

Of erectable magma in the subsurface,

and when there's pressure to get

that magma up to the surface.

And right now neither condition

exists at Yellowstone.

This cross section right here

shows what the Yellowstone

system looks like underground.

Here's the depth in kilometers,

so this is about 30 miles deep,

50 kilometers deep or so,

and we know there's two magma chambers.

Beneath Yellowstone,

there's a rhyolite,

a very sticky high silica magma body.

This is the source of the big explosions.

And then there's a larger basaltic,

a little bit thinner kind of magma,

but hotter beneath that we

know from seismic imaging.

It's a bit like taking an MRI of

the earth that this rhyolite.

Dragon Body is only 5 to 15% molten,

and the basaltic magma body beneath

that there's only two to 5% molten,

so we don't even have that much

irrepetible magma as an overall

percentage of the total area here,

so the conditions required for these big

eruptions just don't exist right now,

so not overdue.

And and because the numbers

don't work out and,

and that's not the way volcanoes work anyway.

Alright now to that other misconception

that a lot of people have it.

Yellowstone eruption is an

extinction level event and Ellie

I hear this quite often that when

Yellowstone erupts we're all goners.

Well, here's something interesting.

Large explosive eruptions are not

associated with mass extinctions.

Big explosions, like Yellowstone,

do not drive species to extinction.

That hasn't happened.

There are some huge volcanic eruptions,

huge outpourings of lava flood

basalts that may have been associated

with some extinctions.

Those kinds of eruptions might

last 10s of thousands of years

pumped huge amounts of lava and

lots of gas into the atmosphere,

but the big explosive eruptions have not

been associated with mass extinctions.

We know this.

We know that we're going to survive

this because this experiment

has actually been run twice.

While humans have been on the

planet the first time

was that one I talked about

earlier 74,000 years ago,

Tobha Indonesia that left this scar

on the island of Sumatra in Indonesia.

This was one of the largest

volcanic eruptions we know about.

As some of you may be familiar with something

called the Toba catastrophe theory.

And that's the idea that this

big Tova eruption occurred at

the same time as a bottleneck in

the population of Homo sapiens.

That was in East Africa.

And this brought about the idea

that we almost all went extinct

because of that OBO eruption.

Well, subsequent research has shown

that the times don't quite match up

the bottlenecks in Homo sapiens were

not at the time of this eruption.

What's more,

some climate records that were

recovered from East Africa and

even archaeological evidence from

South Africa show that there really

wasn't that much of an impact.

Homeless avians just went right on

going through this to be eruption.


26,500 years ago there was another

huge eruption that was from Taupo

on the North Island of New Zealand.

The lake right here in the middle

of the island is the in in the

caldera leftover from that eruption.

Again, we survived it.

Both of these eruptions were bigger

than Yellowstone's most recent

huge explosion,

and we obviously survived both

of these events.

I'm not saying it would be pretty,

I'm not saying I'd want to experience it,

but it's not going to mean the

end of our species.

In fact, that Oba eruption happened.

Some of you may be aware the

hobbits that are subspecies of

human that existed in Indonesia.

In fact, they survived that operation.

They were far closer.

Tetova then home Sapiens in East Africa.

So these eruptions are devastating events.

No doubt about it.

They will alter global climate.

They will have a huge impact and perhaps

some aspects of our civilization.

Electrical grids,

water and so forth will be susceptible

to being messed with by all that,

that ash that would be in the atmosphere,

but it will not drive us to extinction.

I wouldn't want to live through it,

but anyone that tells you that

Yellowstone or any other huge

volcanic eruption explosive eruption

is going to drive us to extinction.

No, we have the evidence that that.

Just isn't true.


number 4 Indigenous people

were afraid of Yellowstone.

This one has been around

for nearly 200 years.

In fact,

the National Park Service actually propagated

this and this might be because in 1872,

that's when Yellowstone

became a National Park.

There were still wars going on between

indigenous tribes and EU S government.

And so there's some sense that perhaps

the early superintendents of Yellowstone

were trying to make the place feel safe,

saying no, don't worry,

indigenous people.

They're afraid of Yellowstone,

so please tourists come in and

join the party at Yellowstone.

But of course, this is complete garbage.

And we know this from in in 1877,

the Nez Perce as they were trying to escape

a conflict with the government

went right through Yellowstone.

They knew Yellowstone very well.

They obviously been there before.

They had No Fear whatsoever,

and they they traversed the area,

and in fact, some anthropologists

that were working in the.

Late 1800s could find no evidence whatsoever

that that indigenous tribes indigenous

cultures were ever afraid of Yellowstone.

The origin of this myth might

have been from William Clark.

This might have been the first

instance that this was recorded.

Clark of Lewis and Clark fame,

when they were coming back from the Pacific,

heading back to Saint Louis.

Lewis and Clark split up.

They took slightly different

routes through Idaho,

and part of Montana.

Clark's route took him through what's

now Livingston Mt and that's where he

met up with the Yellowstone River.

And he had this quote,

which I think is is worth reading.

He wrote at the head of this river,

which Clark didn't actually explore.

The natives,

given account that there is frequently

heard a loud noise like Thunder,

which makes the earth tremble,

they state that they seldom go there because

their children cannot sleep and conceive.

It possessed of spirits who were reversed,

that men should be near them.

Where did Clark get this information?

In fact,

he wrote this in his journal in 1809.

He had come through that area in 1806,

so how did he come up on this

information that indigenous people

were somehow afraid of Yellowstone?

A possibility is a colleague of his,

John Coulter.

John Coulter was part of the core of

discovery of the Lewis and Clark expedition,

but he detached himself in 1806

and actually went back to trap in

the region and in 1807 eighteen 08,

he became probably the first Euro American

to explore the Yellowstone region.

This is a map of Clark from 1814 that

tries to trace out coulters root down

through Jackson Lake area in the Tetons.

Coming back,

and he almost certainly saw Yellowstone Lake.

He probably saw the mud volcano.

Area 2 so he would have been familiar

with some of the thermal activity,

but there's no evidence that he saw

any of the famous geyser basins.

Old, faithful, Grand,

Prismatic spring, and so forth.

Now after that time period the only people

until the 1860s Euro Americans that were

in the Yellowstone area were mountain men,

trappers hunters,

and the most famous might be Jim Bridger,

pictured here.

Abridger had seen all of

the guys and so forth,

but he was well known as a

spinner of tall tales.

In fact,

he liked to claim that in Yellowstone

area he had seen petrified forests

that were full of petrified

birds singing petrified songs.

He saw mountains of glass in which

he could see the reflection of elk

that were miles and miles away.

He saw great geysers of water

shooting into the air,

so you can imagine people sort

of treated the kinds of things

he said with a grain of salt,

and it wasn't until the 1860s in 1870s.

That really thorough exploration found

absolutely all these things that Bridget

was talking about were really there.

But of course, native native tribes.

Indigenous people knew this archaeological

evidence from Yellowstone shows

that there had been people living

in the area for over 11,000 years.

People were very,

very well acquainted with with Yellowstone.

People have been living there for

a very long time, and in fact,

Obsidian Cliff.

Shown right here,

this might have been Bridgers mountain of

Glass that he could see the reflection

of the elk in their Obsidian Cliff.

It has a very high grade of Obsidian

because it doesn't have any minerals in it.

And it's been found as far as far

away as the the Ohio River valley.

So clearly indigenous peoples

were in here using the resources

of Yeltsin and trading them wide.

And in fact,

there's some indigenous tribes

have origin stories.

For Yellowstone,

the Kiawah have an origin story

where a brave warrior jumped into

what's not Dragon's mouth spring

in the mud Volcano area,

and for his bravery,

his tribe was rewarded by the

transformation of the area into just a

wonderful bounty and that became their home.

And the Shoshoni people tell a

story of coyote in the guise of

a man approaching mother Earth

in the guise of a woman,

and asking for some food.

And she says, OK, I'll make you something,

but don't tip over my basket of fish course.

Coyote being coyote tipped

over the basket of fish,

the water rushed out and it

formed Yellowstone Lake.

Paudi ran ahead of the water to the

north to try to stop the water from

flowing and built piles of rocks,

but the water over random

created the lower and upper falls

of the Yellowstone River.

He also went to the South.

Try to block the water going that way,

but was unsuccessful and that's where

we got the Snake River and some of

the waterfalls on the Snake River.

So clearly indigenous people were living

in Yeltsin for a very long time and

many of them have their origin stories there.

Maybe that you're Americans really

assigning their own beliefs to native

cultures when a lot of this came about,

there were a lot of descriptions

of Yellowstone as a hellscape,

and of course,

indigenous people would be afraid of hell.

But of course they had no concept of hell.

This was something that was

introduced to them by Euro Americans,

so that really doesn't make any sense.

It may also be that our value

system at the time of the year of

American value System at the time

was one of permanent settlement,

and so there were no permanent indigenous

peoples in the Yellowstone area.

But of course all of the people in the

plains were largely nomadic and they

went and followed the food sources.

Now the one exception to that

in the area might have been the

people that are shown here.

These are the two kadika or the

Shoshoni tribe of Sheep eaters,

and they were basing their diet

largely on bighorn sheep and they

were in the Yellowstone region.

Mostly year round,

but they still followed the sheep around,

so this whole myth that native cultures

indigenous people were afraid of

Yellowstone was absolute garbage.

They were been using Yellowstone and living

there for parts of the last 11,000 years.

OK number five all Yellowstone

geysers are acidic.

This is something that's quite common.

People think that you touch the water.

You're going to get burned

not because it's hot.

Of course it is,

but because it's very acidic.

Well there are some acid

geysers in Yellowstone,

but the acidity is sort of equivalent

to that of orange juice or coke.

So it's not the kind of thing

that's going to burn you.

In fact,

there are three types of geyser

systems and Hot Springs thermal

systems in the Yellowstone area.

The first is an acidic type

of guys we call these.

Acid sulfate systems and you can

recognize them by the spongy ground.

It's kind of altered rock the the

acid gases have eaten away at the

rock and crumbled it up so very soft

squishy ground and you often see gas vents.

We call them fumaroles or mud volcanoes,

mud pots, frying pans were looks

like an actual frying pan.

Little bits of bubbling happening

on the ground.

The most common geyser system,

though, is actually not acidic at all.

Its neutral chloride system,

neutral to slightly basic like

the guys are right here.

Old faithful, Grand prismatic spring.

All of these systems are

neutral to basic systems.

And finally we have travertine systems.

This is typified by what you

see at mammoth Hot Springs

and travertine is carbonate.

Rock doesn't really have anything

to do with volcanoes,

and the thought here is that the

area around Yellowstone used

to be a shallow inland sea,

and so there are all these limestone

layers that were deposited in this

ancient sea and then buried by

subsequent deposition of various

types of rocks as hot water

circulated through that limestone.

It dissolves some of it.

And brought it to the surface.

And that's where you get

these travertine springs.

So here's a map of Yellowstone.

There's the caldera that formed

631,000 years ago and in green

we've got those neutral geysers,

the neutral chloride geysers,

like old,

Faithful and grand prismatic mostly

clustered in this area here in orange.

We've got all of the acid sulfate systems

scattered throughout the cold air region.

And then the travertine areas

are in pink and we see more

travertine up in the north part of

Yellowstone and a little bit.

In the South as well,

and the thought really,

especially between the acid systems and the

neutral systems that you've got off this,

this cooling magma body.

There's gas and fluids coming

out that are sort of injected

with rain water that percolates

into the system, and where that

water makes it to the service.

You've got the neutral systems,

but at some places the water

and the gas is separate,

and when that happens the gases,

when they make it to the service.

They're quite acidic,

so these gas dominated systems.

Vapor dominating systems are quite acidic.

The fluid dominated systems,

in contrast, are tend to be neutral.

There are some messy places,

and one of the messy it's is

Norris Geyser Basin which is just

on the north side of the caldera.

There you've got amazing

features like Steamboat Geyser,

the largest geyser in the world,

tallest guys in the world.

But then just a few 100 yards away.

Is he kindness geyser?

Steamboat is neutral neutral

chloride neutral to basic kindness

is the largest acidic geyser.

In the world,

so there can be very complications.

Complicated plumbing systems

that these guys have.

It allows some mixing,

but for the most part we can

divide the Yellowstone system

up into the neutral geysers.

The acidic mud pots and mud

volcanoes and then the travertine

terraces of places like mammoth.

Number six I we're halfway through our list.

Now we're getting into some of the

misconceptions that we see repeated

so often in misinformation online.

I love this one.

Yellowstone is always uplifting.

This one's personal to me because

my area of expertise in terms of

archaeology is looking at ground

deformation and when I see stuff like

this it it really makes me roll my eyes.

I actually took this image as a screen

grab from a recent widespread bit of

misinformation that appeared on YouTube,

and the idea that this person was

trying to show was that June.

2020 January 2021,

June 20th you saw the Red line.

It looks like the hill behind Old

Faithful which is here in the foreground

has raised up so clearly uplift,

going on only OK,

these images were not taken from

quite the same place and this

one was clearly manipulated.

This is the same tree the tree looks like.

It's been squished the whole

steam plume coming from Old

Faithful looks really weird.

And what I think is the most egregious.

This is totally ridiculous in my view.

This is January.

There's no snow by any of this.

Somehow the person who made this

thought that they could hoodwink all

of us by taking some random image,

not only manipulating it,

but it's clearly not January.

If you've been or seen any pictures

of Yellowstone in the winter,

it is really snowy and there isn't a

bit of snow anywhere in the scene,

not even in the background.

Which is cool rock to say nothing of

the fact that there are monitoring

stations all over Yellowstone,

so this fits the narrative that

many people try to tell that

Yellowstone is always.

Uplifting and cause uplift is a sign

that perhaps there's magma accumulating.


it turns out Yellowstone sometimes

does uplift,

but it also goes down.

Many people have described

Yellowstone is almost breathing,

it rises and it falls.

So let's have a look at some actual data

showing what's been happening Yellowstone,

so here's he also National Park.

There is the cold air that

forms 631,000 years ago,

and all of these red dots are earthquakes

that have occurred this year in 2021.

We've had about 2600 earthquakes so far,

which is a little bit above average.

Lot of them were in this warm

right below Yellowstone Lake.

There was something like 800 or

900 earthquakes that occurred

right in that area in July.

So now let's look at a GPS station GPS

just like the the GPS in your car or.

We found, but we use stations that are

able to detect really small changes.

Fractions of an inch overtime since 2003.

The GPS station on this side of the caldera.

This is vertical deformation has gone

up from 2004 to 2009 and then down from

2009 to about 2014 and then up from 2014,

2015 and then twenty since 2015.

It's been going down almost

like it's breathing.

Let's look at the other side of the caldera.

This is a mess station near Old Faithful

we see basically the same thing up.

2009 to 2014 down 2014 to 2015 up

and then 2015 to present down.

So they called their rising and falling.

Mrs Norris.

Geyser Basin,

just outside the area just outside the cold

air and all of these are to the same scale,

so each one of these vertical scales

here is a total of 40 centimeters,

so a little bit over a foot.

There's not much going on at Norris,

and then there's a little

bit of uplift in 2013, 2014,

and then substance,

and then uplift 2015 to 2018.

Then it is substance and it's looking

like Norris is starting to go back up now

so Norris doesn't follow what they called.

Era does,

but the amount of deformation we're

talking about these is generally on

the order of 1 to 2 inches per year.

Couple of centimeters per year,

and that's the call.

There are rising and falling.

The fact that it's going up and down

suggests that a lot of this deformation

might be caused by hydrothermal.


gases and water moving around in the

subsurface and there is an awful lot

of hydrothermal activity at Yellowstone,

mud, volcanoes,

geysers, Hot Springs.

It's absolutely everywhere.

We can also go further back in

time and look at what's happened in

Yellowstone since the ice melted in

the area about 14,000 years ago.

So here is a very high resolution

topographic view of the north

side of Yellowstone Lake,

so there we are right here.

This is the Yellowstone River

leaving Yellowstone Lake and on

the north side of the lake there

are all of these little terraces.

You can kind of see these these

ripples in the landscape.

Some of them are marked by

yellow arrows or these

little dotted lines.

And here's a photo of what

those terrorists look like.

There's a bit of high ground here,

slightly lower ground there.

There's a slope between them,

so there's an upper terrace

and the lower terrace.

These terraces were created by

wave action on Yellowstone Lake,

and the fact that there are so

many terrorists means that the

lake was rising and falling.

We can date.

The terrace is based on archaeological

evidence and even looking at ash

layers from cascade eruptions from

like the eruption of Mountain Zamaan

Crater Lake formed 7600 years ago.

There's even you can find

evidence of ash from Glacier Peak.

In in Washington from an eruption

that happened over 13,000 years ago.

When you put all that together,

you find that over the last.

14,000 years or so,

Yellowstone has gone down by about 100 feet.

So Yellowstone's net change since the

ice went away was actually substance,

and it's probably doing this

over time like it's breathing,

but the net deformation based

on the geologic evidence on the

lake has been and it's gone down,

not up so often.

Hear that Yeltsin's uplifting.

It's got to be a favorite thing of people

that are trying to sell their videos,

but the truth is actually

far more complicated and far

more interesting than that.

Another thing you might hear often

is that Yellowstone earthquakes,

meaning magma movement.

There's a lot of earthquakes in Yellowstone.

What causes it?

Is it really magma movement?


let's talk about just how many

earthquakes happened in Yellowstone.

It is one of the most seismically

active areas in the United States.

On average,

there's something like 1500 to 2500

earthquakes to located every year

occasionally can be as high as nearly 4000.

And about 50% of these

earthquakes occur as swarm events.

Since 1973,

we've seen over 50,000 earthquakes.

Here's a map of those earthquakes since 1973.

Here all of the red ones are

just discrete earthquakes.

The blue ones are the swarms and you

can see how they seem to happen in

these sorts of bands of size missing.

Now, over 99% of the earthquakes

are magnitude 2 or less.

They're not felt by anyone.

And since 1973 we had one magnitude 6.

There was a magnitude 6.1 near

Norris in 1975,

two magnitude 529 magnitude

fours and about 400 magnitude 3.

There's usually a few magnitude

threes every year.

The largest event in the

region happened in 1959,

just outside the park.

That was a magnitude 7.3.

That's the largest earthquake that's ever

been recorded in the Intermountain West,

so all kinds of earthquakes in

the Elstar region.

What's driving them?

There are faults galore in Yellowstone.

Here is a map.

You can see the park outlined in blue.

The caldera is in purple and all of

these black lines are mapped faults.

You can see how they're sort of coming

right into the Yellowstone area,

and then they sort of disappear.

And then they come out

some of the South side

of the caldera. The only fault we

see in the call there are these ones

that are sort of associated with the

Caldara itself rising and falling.

These faults are present because the

whole area is being stretched apart and

that's what caused the 1959 earthquake.

That's what we're seeing in this.

Photo here is this carp from that

huge earthquake that happened

just to the West of the park.

These faults almost certainly extend

right through Yellowstone area,

but essentially they were blown apart when

the big caldera formed 631,000 years ago,

so that call there blew a

hole in the faulting system.

There's also a lot of fluid, and yell

says we have tons and tons of faults.

We have a lot of water moving

around in the subsurface,

and as an example of that,

let's look at the Maple Creek earthquakes

from thousands of earthquakes that

happened in 2017 and I'm going to

play a little movie right here that

shows first these events in Map view,

but we're going to rotate it

and look at it inside view.

The color indicates when these events happen.

Blue starting in June of 2017 going to

the Reds that were in September of 2017.

You see how it's sort of fanned

out from that center piece.

That's evidence that these

are driven by water.

Water is diffusing outward and it's

helping these false disruptions,

so the combination of all of these faults

in the area with tons and tons of water.

We know there's water given all of

the geyser activity and thermal

activity in Hot Springs and so forth.

That's what's driving a lot of the

earthquakes in the Yellowstone region.

Here's another misconception.

An earthquake will trigger

a Yellowstone eruption.

This sort of makes sense, right?


we often talk about magma being like a soda.

It's got gas dissolved in it.

And what happens if you shake a soda right,


So if you shake magma,

wouldn't that also cause an eruption?

This plot up here is something

I pulled off of Google.

Google searches for Yellowstone eruption

between July 2nd and 9th of 2019.

This little spike right there

coincided with a magnitude 6

earthquake in California on July 4th,

2019 and then there was a magnitude

7.1 a day later in July 5th.

That spike right there is people

searching Yellowstone eruption and

associated with this magnitude 7.1.

Well, we know that this isn't true as well.

Just like we can demonstrate

that the Yellowstone eruption is

not going to wipe out humanity,

we can demonstrate that earthquakes

don't trigger Yellowstone eruptions,

and that's because there are a huge

number of earthquakes in the western US.

The entire western US is

being stretched apart.

That's why there's all those faults

in the Yellowstone region and

extends all the way from Yellowstone

all the way to Eastern California.

This whole area of the basin and range,

which you can sort of see from

a satellite view here.

This is the Great Valley, California.

The Grand Canyon is in the

foreground and all of these ripples

are mountain ranges and valleys.

But Mountain Range valley.

Topography formed because the

area is being stretched,

so every one of these mountain

ranges is associated with default,

so they're going to be magnitude

7 earthquakes all the time,

and in fact just in the past year we

had a magnitude 5.7 near Salt Lake City

that was in March mid March of 2020,

and it's 6.5 in central Idaho at

the end of March 2020 there was a

magnitude 6.9 here in 1983 as well,

so there are a magnitude

7 events all the time,

six or seven in the basin and range.

We know there's magnitude 9 events off

the coast of Oregon and Washington.

There's a potential for magnitude

8 events in California.

The last time Yellowstone

erupted 70,000 years ago.

There have been and there was a lava flow.

There have been thousands of earthquakes

in the western US since then.

If we go back to the last big

explosion 631,000 years ago,

there have been 10s of thousands

of magnitude 789 earthquakes.

None of them have caused

Yellowstone to erupt config way,

so it sounds like it might make sense,

but it doesn't work for the L sound

system triggering of eruptions by

earthquakes is a relatively rare thing,

and this is just for fun.

Occasionally I also hear people say, well,

yeah, what about nuking Yellowstone?

You know what if Kim Jong-un or

Vladimir Putin or some James Bond

villain decides they're going

to nuke Yellowstone and wipe out

the entire United States?

Not going to work.

It's going to wipe out one of the

most gorgeous places on Earth.

It's not going to cause an eruption.


I mentioned that magnitude 7.3 earthquake.


here's a magnitude scale for earthquakes.

The energy released here magnitude

7.3 is much bigger than the

atomic bomb that was dropped on

Hiroshima in World War Two.

It's not too far off from the

largest nuclear test ever conducted.

That actually happened that

that 7.3 happened in the ground

right next to the magma chamber.

No effect whatsoever,

so no Yellowstone if you nuke it,

you're going to wipe out a gorgeous place.

It will have no impact on

the volcano whatsoever.

Alright, #9 Yellowstone is heating up.

This one's fun.

We hear this one a lot too.

Whenever there's a big geyser eruption or

or if there's a change in thermal activity.

Also must be heating up.

No, Yellowstone is dynamic.

That's the keyword.

It is constantly changing.

It's one of the things that

makes it so interesting to study,

and I've got a great example

of that right here.

This is from a colleague of mine,

Greg Vaughn,

who studies thermal satellite data.

He can look at Yellowstone heat from space,

so every year he looks at newest data and

tries to see whether anything has changed.

One year he zoomed in on this part of

the eastern side of Yellowstone caldera.

And this is what he saw.

The blue areas are lakes areas that are

outlined in red are known thermal areas.

But then there's that spot right there,

no red around it.

So what is that?

Is that a new thermal area,

or is it some sort of weird anomaly?


he was able to get his hands on some air

photos that are repeated every few years,

and this is what it looked like in 1994.

Here's an existing thermal

area we already knew about.

That's the area he was focused on.

So in 1994, 2003 it's starting

to look a little funny.

For 2006, there's definitely

something going on right in there.

2009 look at that.

Trees have started to die off

and by Tony 15 this looks like

a brand new thermal area.

In fact, that's what it

is we caught in the Act,

a thermal area forming at

Yellowstone and we'll be able

to go out and have a look at it.

Here's that thermal area close up.

And here's the thermal view,

taken with a thermal camera.

Parts of it are quite hot.

In fact, just below the surface

it's near boiling temperatures.

But then you've got areas right

next to it that are quite cool.

This must happen all the time

in Yellowstone to result in all

of the thermal features we see,

but they don't just heat up.

They also cool down.

And here's an example of that.

Here is the Lower Geyser Basin

and Midway Geyser Basin that

colorful feature right there

is Grand Prismatic Spring.

And if we look at the thermal

satellite image for that,

we can see grand prismatic very warm.

Lots of these areas are quite warm.

The river is warm from all

of the thermal input.

This is Brimstone base and brimstone is on

the southeast side of Yellowstone Lake.

If we look at the thermal

map for Brimstone Basin.

It's actually cold.

It's colder within the thermal

base and then it is outside.

Thermal areas don't just heat up,

they cool down to they come and they go.

That's what I mean by dynamic.

The same is true of geyser activity,

so of course you almost Steamboat Geyser.

I'm sure it's been erupting

prodigiously over the last few years.

Here's a video taken by my colleague Jamie

Farrell from the University of Utah.

Steamboat is located right in here,

and you can see it's it's

actually coded a lot of the trees

in the area with silica mud.

These features start up and stop.

This is how they work during the time

that Steamboat became very active.

Giant Geyser nearing Old Faithful

actually mostly turned off Giantess

Geyser hasn't been particularly

active for the last ten years.

After over 100 years of being pretty

active erupting a few times every year.

This is that dynamic nature of

Yellowstone geysers start and stop.

Thermal areas come and go.

That's Yellowstone, being Yellowstone.

And finally our last misconception.

Yellowstone could erupt tomorrow.

A lot of people like telling you this.

Well you don't know Yellowstone

could hurt tomorrow.

Yellowstone will not erupt tomorrow.

We know this because we monitor

yells are very, very careful.

Yellowstone is one of the most best active,

best monitored areas in terms of seismicity,

there's over 46 seismic stations

in the region.

This is Bob Smith from the

University of Utah.

One of the the folks it really is spent

a whole career studying Yellowstone.

Looking at one of those seismometers

were able to locate.

In some places,

earthquakes with negative magnitudes.

Negative just means it's so

small that it goes below 0.

On the arbitrary scale

that's been been defined,

so we can look at extremely small

earthquakes in the Yellowstone region.

If Yellowstone were to become much more

active, this is the kind of thing we

would see with this seismic network.

There are also dozens of

GPS stations in the region.

I showed you some data from that earlier.

It looks something like this.

There's the GPS antenna,

it's cemented to the ground.

It's got power and telemetry over here.

We've got some in red that are deployed

for six months out of the year,

and then the green ones are there

year round and there's dozens of these

always reporting their information back.

We can see the ground rise and fall

if something were really going on,

we would expect to see some

extreme deformation,

and that would be something that would

be picked up by these GPS stations.

We also know that these

Yellowstone eruptions,

lava flows,

and explosions are usually preceded

by changes in the magnet system and

this is work from Christy till at

Arizona State University and she

is here looking at a lava flow.

And when she digs out the crystals that

are in the lava flows and the ashes,

she can see how there's zone.

You see,

it's got these these concentric zones.

That's evidence that there is

material that comes into the system.

Sort of rejuvenate sit,

so this kind of activity would be stick

out like a sore thumb we would see.

A really amazing level of seismicity,

ground uplift,

really different than what

we've seen in the past.

Changes in thermal emissions and activity

that's happening all over the park.

These are the kinds of things

we would expect to see as this

cooling magma body rejuvenates

itself and there would be decades,

centuries, perhaps millennia,

of warning prior to this

sort of thing happening.

So before magma can get to the service,

a lot has got to happen,

and we're very well tuned to see that

it's not going to happen tomorrow.

There's no evidence that it's

going to happen along.

So those are our misconceptions.

Hopefully I've convinced you

not to use the S word anymore.

Yeah, so it's not over do the math,

doesn't workout and that's not

the way volcanoes work.

I wouldn't want to have to live

through a big Yellowstone or any

other caldeiras system eruption,

but we would as as a species

lived through it.

Indigenous people were not

afraid of Yellowstone,

they've been there for 11,000

years at least and made huge use

of the resources in the region.

Some Yellowstone geysers are acidic,

but not all.

In fact,

the most iconic features are actually

neutral to basic Yellowstone breathes,

it goes up and down.

It's not always uplifting,

and Yellowstone earthquakes

are largely driven by motion.

Long existing tectonic faults with an

assist from all that water beneath.

An earthquake is not going to

trigger a Yellowstone eruption.

There have been thousands of strong

earthquakes in the Western U.

S. Yellowstone has been

quiet through all of them.

He also isn't heating up.

It's dynamic, it's always changing.

And no, sorry,

Yellowstone is not going to work tomorrow.

We love talking about Yellowstone,

so if you'd like to learn a

bit more about the system,

about some of the activity that's going on,

we've got a couple of ways that

you could get more information.

We do monthly video updates of activities.

Sometimes we're able to do

them on site in Yellowstone,

and you can find those on the Y via web

page or on the USGS YouTube channel.

We've got USGS volcanoes,

Twitter Facebook, and Instagram.

We try to put out a lot of information about

Yellowstone and answer questions that way.

We even do annual reports.

This is from the 2020 annual report.

We try to get the annual

reports out within a few months.

Of the the preceding year,

so of course we're going to be

working on the 2021 report two,

and we do a weekly article that

we call Cold Air Chronicles,

where we talk about some aspect of

Yellowstone geology or history,

or recent research.

You can find that on our social

media feeds or on our website.

It's even reprinted in some

local local newspapers.

And then finally you can always email us.

We're always happy to talk Yellowstone.

We we love it.

So if you have questions,

you can always drop us life.

You heard something you're not

sure about if you'd like to just.

Chat about this place.

We'd love to hear from it.

So with that I guess I'll throw it

back to Amelia and I want to thank

everybody for taking the time to spend

the evening talking about Yellowstone.

That was absolutely excellent,


Thank you so much for your

talk today and you know,

I think we learned a lot tonight.

But you covered this.

Is absolutely fantastic.

Now I want to go ahead and remind

everyone we're going to go ahead

and open it up to the question and

answer portion of this lecture and

we have been monitoring what's been

coming through so far and I will go

ahead and ask those first out loud,

but just a quick reminder if

you'd like to submit a question,

just click on the Q&A chat window

on the upper right hand corner of

the screen and submit your question.

So Mike,

here is your first question of the day.

Here we go.

This first one was asked Uhm,

how does Yellowstone compared to Krakatoa?

Ah, good question.

So Krakatau is a stratovolcano system

that collapse a bit like Crater Lake,

so not necessarily a caldera system

like Tova or Taupo in New Zealand

or can't be for Gray and and but it.

But it had that sort of rupture.

It erupted so much material that it

could sort of fell in on itself.

Yellowstone is way bigger by one

or two orders of

magnitude that Krakatau big

eruption in 1883 was a huge one.

Uh, but still quite a bit smaller than

Yellowstone, so different scales,

but I think that particular option at

1883 eruption illustrates some of the

challenges that we face in volcanology

that size of eruption is much more

likely to happen in our lifetimes than

something the size of Yellowstone.

And so in some ways we think when we

think about volcanic activity and

what what the hazardous ones are.

Sometimes people tend to skip over

those intermediate sized ones like

Krakatau or or Tam Bora in 1815.

And they go from something that's

mounting Helens eyes straight to.

Yellowstone size would help.

Both sides are to be size,

but the ones that you're skipping

over Pinatubo Novarupta.

Those are the ones that are more

likely to happen on human timescales,

and they could be regionally,

really really devastating.

So Krakatau was a huge eruption.

It's still quite a bit smaller

than Yellowstone.

Awesome. Alright,

the next question is what happens

to the West of Mcdermitt caldera?

Are there other call Darius buried?

By more recent deposits?

Or did the mantle plume come into existence

starting at 16 million years ago?

I love this question, so the question is,

is referring to me see if I

can jump back to that map?

Is referring to this

Dermot Caldara right here,

and notice that there's nothing

going on across Northern California,

so if did, is this where the

hot spot really got going?

For a long time we thought it was

that the Columbia River basalts was

sort of the first outpouring of

material from the Yellowstone system,

and it coincided with the Mcdermitt caldera.

And that's when we got this

nice channel called Earth.

More recent research, though,

has suggested that actually.

The Yellowstone hotspot has

been around for over 50 million

years and it started someplace

offshore of Northern California.

It traversed this region,

but a whole bunch of tectonic activity

in the last few 10s of million years

have smeared out the evidence for

Yellowstone all through the Central

Oregon and Northern California.

You can see some of it geochemically.

You can look at the chemistry of some rocks,

and it looks like Yellowstone.

Somewhere around 2021 million

years ago it went quiet,

so during this phase when it was

traversing specially Northwest Nevada,

perhaps because all of that melt was

trapped underneath a subducting slab.

Basically a piece of rock that was sort

of stuck underneath the continental crust.

It's or prevented the Yellowstone

magma from burning through,

and then it punched through in a big way.

1617 million years ago.

That's why we had this huge outpouring.

The Columbia River basalts

and then Mcdermitt caldera.

And the nice trail going to Yellowstone.

So it does look now like yeah,

Yellowstone's been around for

fifty million years or so.

Started offshore of California,

but the evidence for that is smeared

all through California and Oregon.

It's hard to really see.

And then there's a several million

year quiet period that occurred

when the hot spot would have

been traversing Northwest Nevada.

Yeah, that's a really good question.

That's relatively new conclusions,

and pretty exciting to think that

Yellowstone's been around a lot

longer than we originally thought.


definitely we got a combo and some

feedback and a question here from

Anna she says super interesting.

Thank you and wish you physicist and

I never knew some of these facts.

My daughter is asking in the tow

bar eruption.

Why is the scar surrounding the

center of the eruption while the

center itself seems indistinguishable

from the rest of Indonesia?


so that's looking at this feature right here,

so you've got the Toba.

Caldara is filled with water,

and it's got a lake,

but the middle is island.

And that's because after caldeiras form,

often there is a sort of a pop up in

the middle as magma recharges the system.

It lifts up the middle of the caldera,

so we get something called the

resurgent Dome and you can see these

in most called errors around the

world to be is a great example in

Long Valley in Eastern California,

you've got a resurgent Dome in the

middle and there's a Moat sort

of around the resurgent zone.

Vias Caldara in New Mexico.

Same thing and also in in Yellowstone,

Yellowstone, there's actually

two resurgent domes,

one on either side of that

sort of elongated caldara.

So that's sort of the way

called there is work,

they they bounce up shortly after

the big caldera forming eruptions

as the magma chambers refilled.

So that's why you see this sort of

upwarp in the middle of the lake.

Good question.

Yeah, there's a lot of great

questions tonight, that's for sure.

Alright, somebody is asking what

changed old faithful eruption pattern,

not be full anymore.

So I've seen a rumor floating around that

old faithful isn't faithful anymore.

I don't know where that comes from it is I.

I think that's been claimed online

by a few people and it's been.

It's made up.

That said,

it's not constant through time

back when Old Faithful was

first described in the 1870s,

it was erupting about once every hour.

Now it erupts about once every 90 minutes,

give or take.

There's a pretty big uncertainty there.


it's happened mostly in the last

few decades that it got longer.

In some cases it's been due to.

Earthquakes that are in the region.

I said earthquakes won't

trigger Yellowstone to erupt,

but earthquakes can affect the geyser

systems because the guys are some there.

They like the plumbing in an old house.

They're really fragile and if you

shake them just like if you shake

the plumbing in an old house you

things are gonna break and so you

often see after a large earthquake

somewhere in the western US and even

there was a case of this happening

in Alaska and Earthquake in Alaska

the seismic waves come through and

they sort of mess with the plumbing.

System and you can get changes in

the interval between eruptions and

so overtime the last few decades

the old faithful system has gone

from about 60 minutes to 90 minutes,

but it's still pretty faithful.

There was a time, however, about.

650 to 800 years ago where we

have evidence that both faithful

did not erupt at all.

It wasn't faithful, period.

During that time frame.

We know this because there are trees.

Preserved in the Old faithful mount,

so there are actually old dead trees

that are basically petrified and we

can date those trees and find out

that there are a few 100 years old

that time period when old faithful

was not erupting 'cause we know it

was interrupting 'cause otherwise the

trees would have been able to grow there.

That corresponds to a major drought

that affected much of the Southwest.

In fact, during this drought is when many

of the indigenous people of the Southwest,

those Cliff dwellings,

and so forth were abandoned.

So it looks like old, faithful,

maybe in part controlled by

the availability of water and

during major sustained droughts.

It may dry up.

We do know that some geysers

during wet years and dry years,

their intervals become a little

bit more frequent during wet years

and less so during dry years.

Old faithful appears to be

to be one of those.

Right? Our next one is from Todd

and this is a two parter question

with a little bit of feedback here

burst info foremost. Thank you.

I really enjoyed this talk and look

forward to the monthly updates.

Very happy guide.

My first question is that I am an

Earth science education major in

Utah and I'm wondering if there are

any jobs specifically linked to the

Yellowstone Volcano Observatory that

deal directly with interpretation

and working with the public outside.

Of the Rangers working within

the National Park Service so.

Interesting question.

We we don't have really specific.

Outreach jobs that are outside the park.

And and so I I think that would be my my.

My default is to to go with the park.

Just because the opportunities there

are huge. You know there are this.

This past year four and a half million

people pass through Yellowstone

Park and they're going there.

Of course, to see bison and elk and wolves,

but. Everyone stops at Old Faithful.

Everyone sees these amazing geyser basins,

and so there's a real opportunity

for engagement.

I think the park is is doing a

pretty good job of engaging folks

in telling the the geologic story.

I think we can do more as well.

Some of the the agencies that make

up Yvo can help that mission,

especially through the use of social

media and videos and so forth.

I'm not aware of any real specific

jobs for that outside the park,

but the park has some really neat programs,

like a geoscientist in the park.

That's run through the Geological

Society of America and other programs

like that for interns where people

can go and make a real difference

with with outreach and.

And frankly,

I found my occasionally I get a

bit demoralized by all of the

misinformation that you see online.

But then you go to Yellowstone and you

see the wonder in people's eyes as they.

Watch a geyser erupting and and you realize,


If people are really captivated

by the place and the the the noise

online is is just that it's noise.

The real experiences there,

so I'd encourage you to look at the

sort of geoscientists in the park

programs as a as a start and perhaps

the University of Utah since they

they do so much with earthquakes

in Yellowstone they they put out a

lot of good information that might

be a place to look.


Great a great suggestion actually

it's true now.

His second question to his original was.

Why are there so many few faults

inside the caldera except at the

Sour Creek and Mallard Lake domes?

So the sour cream and lake

are the resurgent domes?

See if I can pull up that map.

So these domes. Sour Creek is over here.

Mallard Lake is over there.

This is the resurgent domes that

popped up after the cold air formed.

And as they pop up they start

cracking so you

get all kinds of faults associated

with the resurgent tops,

the tectonic faults, the regional

faults probably go through here.

But Yellowstone blew up

all the evidence for them,

so almost certainly based

on the earthquake maps,

we can see that there's almost

certainly extensions of these

faults that run through the area,

but we don't see the surface

expression of the false 'cause

it's been just obliterated in the

caldera form 631,000 years ago.

There may be some evidence that the

floor of Yellowstone Lake there's some

of these faults continued through

Yellowstone like there may even some

of these faults have the potential

to add magnitude 6 and seven earthquakes.

That's actually the big hazard on human

timescales in the Yellowstone region.

Is a strong earthquake.

It's not a volcanic eruption and the last

lava flow came out 70,000 years ago,

but there are probably magnitude

7 earthquakes in the region

every hundred years or so.

Last one was in 1959.


so something that you mentioned earlier,

there was some feedback that's going

to sound very familiar with you

just mentioned they had said this

is all very fascinating and much

needed at the time where so much

misinformation is spread on social media.

So they have that same feeling too wanted to.


I know I spend a lot of my time

trying to answer questions and I I

think most people you know they're

not looking to be misled by by some

of the misinformation that's out there.

You have honest questions and you

hear things that Yeltsin's uplifting.

And of course, if there's an earthquake,


If there's, you know,

hundreds of earthquakes happening in

Yellowstone in a given few day period.

That sounds alarming.

If that were to happen at.

Not Baker Glacier Peak or something

like that.

It would be alarmed because that's

not the way those volcanoes behave,

but This is why we spend so much

time installing instruments and

volcanoes and trying to understand

their background levels of activity.

We want to know how they behave

over long periods of time.

Yellowstone behaves with lots

and lots of earthquakes,

ground rises and falls.

The guys are starting and stopping and

ground is warming up and cooling down.

That's Yellowstone.

That's background for Yellowstone.

So what we want to do is define that.

Background and look for the

deviations and it's very easy for

some people say well any earthquake

at a volcano is related to magma.

That may be true at some volcanoes,

but not at Yellowstone.

That's why we spend so much time trying

to define that background. Alright.

The next question is from Samuel.

He would like to know how are the

elevations measured to such a precise

accuracy at the points discussed in #6,

Yellowstone is always uplifting.

We use the same technology in terms

of GPS as isn't your phone in your

car so forth only we do a slightly

different type of processing.

Instead of having the.

Satellite signals tell us.

Where we're located,

we actually look at the frequency.

Essentially the wave itself,

and we use the wave to figure out.

Where we are, where the the ground.

The station is an example.

I could give would be let's say

you're listening to the radio and.

The DJ comes on and says hey,

this is this is.

KYSKYNP in Gardner, Montana.

Well, they just told you

they were in Gardner Montana,

but what if you listen to the

actual wave that the person's voice

was carried on and you could use

that wave to not only triangulate?

Yeah, OK, they're in Gardner.

You could figure out which room of

which building they were in in Gardner.

That's sort of the way we use GPS.

We don't use the same signal that

phones and cars and so forth use.

We use the carrier of that signal to try

to figure out a more precise position.

And so we're still. It's all the same.

The same stuff, basically.

But we're we're doing a slightly different

type of position that allows us to get

millimeter scale accuracy with GPS.

It requires a lot of computational

processing and and tricks,

so it I think the the radio analogy

is the best one I've ever come

up with for how to try to explain

what we're trying to do.


And it's not the only way we

measure deformation as well.

We also use satellite signals that

essentially take pictures like radar images,

and then we compare those overtime.

We can see the ground rising and falling,

so there's a couple different ways

we have for for measuring that and

going back in time, we did surveys.

We did the same kinds of things

that you might see people out

surveying and construction site.

We use those techniques to watch how

the ground is rising and falling,

so there's a lot of different ways,

but GPS is sort of our work

or course these days.


Ben would like to know he goes.

I have a question about Frederick

eruption and the associated excuse me

the associated hazards in the park.

Imagine we could go back in time

to the day before the explosion

that created Indian Pond or any

other explosive explosion crater.

What would we see at the site

and would there have been hypo

excuse me hydrothermal system with

active surface expression?

Like the geyser basins at

Sulphur Terrace today?

Or would it have looked like

an inert patch of forest?


so very good question.

I didn't talk much about hydrothermal

explosions in Yellowstone.

A phreatic explosions.

These are basically steam explosions.

They don't necessarily involve magma,

it's just water flashing to steam

and water flashes esteem.

It expands really fast and.

Blows up and so that's what

we're seeing right here.

This is Indian pond on the

north side of Yellowstone Lake,

and in fact Mary Bay is one

of these steam explosions.

Mary Bay is actually the largest steam

explosion in the world that we know about.

It's about a mile and a half across,

so these were almost certainly.

Geyser basins.

Prior to the explosions,

we can see that in the debris that

came out that basically they're

blowing apart geyser basins,

some of them still are geyser basins.

There's some craters beneath

the waters of Yellowstone Lake.

And where those craters are, we still

see some some thermal activity today.

They tend to be in these neutral chloride

ones and ones that have the guys,

not necessarily the acid ones,

because the answer was already

gassy right there already.

Lots of gas that's coming out there

whereas the neutral chloride ones

the neutral to basic ones are fluids.

And if you want to generate a large steam

explosion you need to move that fluid from

water to steam as quickly as possible.

Then it expands very quickly,

so these phreatic explosions

are basically like super.

No, I can't believe I just said that.

Epic Geyser eruptions,

but they can be huge and and they

are a real hazard in Yellowstone.

They happen every year,

give or take to very small extent.

The big ones there have been a dozen

or so big ones which are a few

hundred feet or more across that

have happened since the last Ice Age,

so they probably looked like

geyser basins when they happened,

not just random areas.

And it was that water flash into

steam that caused them to explode.

Good question.

Yeah, these questions are

amazing and they keep coming.

Somebody wants to know if there's

an eruption in the future.

Will look more likely be to the

Northeast because of the way the

crust is moving over the hot spot.

Alright, another good question,

and we don't really know,

so the thought here is that

as the North American plate

is moving in this direction,

that means the next Yellowstone

eruption might happen out in here.

Certainly possible.

We don't know whether the current

Yellowstone system is done or not,

and in our short lifespans we

probably won't ever really know,

but it's possible that things are sort

of moving on one of the challenges

though knowing whether or not we'll

ever see anything to the Northeast here.

Is that we're getting into some

much thicker continental crust.

The crust through this area is the part

that's being extended to being pulled apart.

And so it's thinner once you get

past the Beartooth absaraka.

This sort of volcanic ranges right?

Or the old volcanic ranges right?

In here you get into much

thicker continental crust.

It's unclear whether or not the hot

spot will be able to burn through that

thicker crust before the plate moves on,

so we don't know whether Yellowstone will

ever have activity off to the Northeast,

or whether this crust is just too thick.

So some people have suggested

that the fact that the.

Time between big eruptions super

eruptions is getting longer.

Might mean that as it's coming closer

and closer to the thicker crust,

it's having a harder time,

but that sort of speculation.

So yeah,

reasonable to think that the

next thing might happen appear,

but we don't know whether.

Whether the system will be able

to burn through that much crust?

Awesome, excellent.

Christian wants to know you mentioned

that most of the earthquakes are

caused by the water getting into the

pre-existing fault faulting system.

What could be other sources

of seismicity in the area?

Well, of course,

another source of seismicity,

Nelson could be magma moving around,

and we do know that at times

magma does move around.

So for example,

in 1996 the Norris area started to

uplift and we saw this not with GPS,

'cause at the time we didn't

have GPS in the region.

We saw it with satellite radar.

And that uplift lasted until the early 2000s,

and then it stopped and

infected it back down.

A little bit that uplift.

Appears to have been a magmatic intrusion

that happened about 10 miles deep or so.

And that that magma system may have

ultimately led to some shallower

uplift and subsidence in the

Norris area in the years past,

even up to today.

That's caused mostly by water,

and we know that based on the

shape of the deformation that

the depth of the deformation,

and just how fast things turn around.

So an interesting example of that is

let's see if I can find that plot.

There was some neat uplift.

In Yellowstone, in the Norris area,

right here in 2013 to 2014,

this was very rapid.

I mean, it doesn't look like much,

it was only a few inches,

but it was quite rapid for

Yellowstone and right at the top

right at this peak of uplift there

was a magnitude 4.8 earthquake.

There's the largest earthquake in

Yellowstone in decades the next day.

North started to go down.

It was as if water was backing

up behind a valve like a closed

valve and then that valve broken.

That was the earthquake and the

water was able to drain out so

the water pumped up the ground.

Busted valve water drained out.

So magma is moving around at sometimes.

And and that can cause some earthquakes

and there is still the I say the

swarm that we have the biggest

question about happened in 2009,

2010 in Yellowstone Lake.

There was an earthquake swarm and this

is the only swarm that was associated

with deformation of the ground.

So there was a swarm of

earthquakes that occurred.

So little line right in here and we

saw a slight bulging of the ground,

and so that would suggest that

something was pushing in there and and

pushing the ground out of the way.

It's possible.

Such magma it's possible it

was water we don't know,

so there are potential for a few of

these forms to be caused by magma moving

around 'cause we know it's down there.

We know that there are some magmatic

intrusions that happen from time to time.

So that's another source,

but really the the bulk of the seismicity

appears to be driven by water moving

around in these existing faults.

OK, someone had asked earlier.

Is there any connection between the Cynthia

landform and the Yellowstone caldera?


let's see which what was the.

What was the other landform?

So let's see.


so that is this terrain that's.

Well, I I hope I hope I know

what I'm talking about here.

I believe it's the landform that

sort of in the the forearc area

of the Pacific Northwest and.

And yes, this is some of that stuff

that looks like it probably was

part of the Elston hotspot when

it was in the area of Northern

California and the entire.

Coast Pacific Northwest coast,

especially in Oregon,

is undergoing some very strange tectonic

motion and it's carrying rocks that

formed down here up to the north.

So a lot of the terrain in here.

Actually has a Yellowstone

Geo chemical signature.

But it doesn't appear like

this nice line of cold air is.

It's smeared out because of

all that tectonic motion,

so there does appear to be

a yellow signature in here,

and some of these rocks,

but it just doesn't look like this

nice clean trend of caldera systems

that we've had since McDermott formed.

16 or so many years ago.

OK. Alright, let's see what our

next one is here. Let's see.

Avery says if an eruption was imminent

with would there be anything we as

humans could do to slow or stop it?

And if yes, what would you want to do?

Well, would you want it to

make sure to run its course?

Fun fun question.

'cause we sometimes talk about like

diverting lava flows and there's a

real debate there about whether you

should divert a lava flow or let

nature run its course in the Elvis.

There's nothing we could do.

There's no.

Every and I and I know there are

suggestions out there and and

the latest suggestion that's been

around for a few years now is well,

why don't we drill into Yellowstone?

And pump cold water in there

and cool off the magma chamber.

And this was actually a proposal

that was made by an engineer who

does some work for NASA and it

kind of went viral because it got

sent out to the BBC and and it.

It sort of took on a life of its own,

but that wouldn't work and there's

a few reasons why one is that

the calculation that the engineer

did sort of back of the envelope

thing and he never accounted for

the fact that there's more heat

coming into the system.

So it's sort of like trying to cool

off a pot of boiling water by pouring

little bits of cold water into the top,

but not turning off the burner.

Heat sources is there.

It would be a massive expense

and wouldn't work.

You'd have the potential for

harming all of the geysers.

I mean,

imagine if old faithful shut off

because you drilled a hole and

pump some cold water in there.

That would be a travesty,

and it's at this point kind of a.

A solution that's looking for a problem.

Yellowstone is not a problem at

this point isn't showing any signs

that it's going to do anything,

and there are called air systems

like this all over the world.

This has always been sort of a mystery.

Why pick on Yellowstone?

But why?

Why make Yellowstone the boogeyman

when there's tova and Taupo,

and this is called those systems everywhere

Japan in the Philippines and Indonesia,

Europe so?

I think that proposal for you like drilling

in Yeltsin only wouldn't wouldn't work.

It's just unnecessary.

Would would do more harm than good

would cause a huge expense and and.

And there's bigger societal

problems that that we that we face.

So no,

there's nothing we can really do

to stop Yellowstone eruption.

And in most cases for volcanic eruptions,

the best thing we can do is to

get out of the way.

And so that's why we invest so much in

all volcanoes on these monitoring systems.

Early warning systems understanding

what's coming.

Being able to forecast when it's

going to arrive and telling

people that are in harm's way.

To get out of the way.

So the best thing we can do when Volcano

erupts is to not be there when it erupts.

Bigger issue for larger eruptions,

but that's still the best.

The best defense we have. Alright.

Walter wanted to know if the Yellowstone

system were to erupt with some lava flows.

How long might it be active for years,

centuries, millenia?

Good question.

So these lava flows that come out

of Yellowstone are humongous.

They are epically big.

Hundreds of cubic kilometers, right?

So the eruption rates have

to be reasonably high,

but probably these eruptions last four.

Years, decades, millennia is pushing it.

But yeah, decade decades long eruptions

of these lava flows just sort of

steamrolling everything in their path.


They're huge too.

If you ever stand at Old,

Faithful and look around,

you had all of the higher topography.

Those are all lava flows.

So these lava flows are really thick,

hundreds of feet thick, really massive.

These are epically big flows and

there are these sticky stuff.

It's not like Hawaii,

they're really runny flows.

These are really it's basically walls

of rock moving across the landscape.

So yeah,

those eruptions probably last

for years to decades at least.


OK, let's see here, you know,

we have some other ones.

I'm getting to those.

Let's see Virginia she would like

to know what is the similarity,

if any, between early Earth and

the environment of Yellowstone?

Oh, that's a neat question.

So environment wise I think the

real question there is about the Hot

Springs because. The Hot Springs.

All of those magnificent colors

that you see in a post like Grand

Prismatic Spring are because there are

bacteria living in the Hot Springs and

absolutely there is a suggestion that.

So these Hot Springs may duplicate

the kinds of conditions that

existed early in Earth's history,

and in fact, so some of you may

have heard of stromatolites.

These are some of the oldest living things.

Allergy that kind of formed on these rocks.

There are still some stromatolites

today in in Australia,

but these are the oldest kinds of

fossils that we know about the

show that origin of life there are

stromatolite like things in Yellowstone

in some of the Hot Springs and some

of the Hot Springs to have yielded

amazing discoveries in terms of the

bacteria and stuff that are living

in in the basis for the PCR tests

that are being done to detect COVID.

It is based on a bacteria that was

discovered in Yellowstone in the 1960s.

A bacteria called thermos aquaticus.

So yeah,

it is entirely possible that the

thermal basins in Yellowstone look

a bit like what early Earth might

have looked like,

and certainly some of the life

we see in these places might be

somewhat similar to the kinds of

things that were present when life

first evolved on Earth.

Alright. Let's see you have a few more here.

Let me get to those and I would like to

know do we know how the Snake River formed.

The eastern SRP reflects the

path of the Yellowstone hotspot,

but how about the Western SRP?

And why are these two parts

geologically coherent? Or are they?

I'm sorry to say that I don't

really know much about the western

part of the Snake River plain this

area right in here and why it is.

It is so smooth.

But there are some folks may,

perhaps on the call, that,

no, what that is, but I,

I can't say if you want to email

me that that question I'd be more

than happy to ask around some of my

colleagues and see if I can look that up.

There is an interesting track

volcanism that extends backwards

from the hot spot to the West

towards present day Newberry Volcano.

There's a a young that goes in that

direction, which is really wacky.

You know,

of course it gets younger along the

Snake River plain if you go this way.

But there are certain types

of volcanic rocks younger.

If you go towards Central Oregon,

and that's not really well

understood either there's some.

Ideas out there about how how

tectonics are happening in the

region that might allow for that,

but the Yellowstone system,

even though we draw it as this

very simple system going up

the snake with the plane,

the eastern part of the state.

But it's it's complex.

There are a lot of mysteries.

That we have yet to really solve,

and I'm sorry to say I don't

really know the origin of the

Western snake there playing,

but if you drop a line to to

that email address Yvo Web team,

I'll do my best to figure that out.

I can let you know.

Excellent. Dave has turned

activity significantly affected

some of the Yellowstone features.

I'm thinking of people throwing

things into the Hot Springs

or walking near Hot Springs,

but there could be other

things occurring as well.

Tours have definitely affected

the Yellowstone system,

and it's mostly from throwing stuff in.

The best example I can think

of that is morning glory.

Pool morning glory is near Old faithful.

It was for a long time right next

to the road into Old Faithful.

And it was one of the first stops

that people made in the old faith.

Larry is a beautiful blue pool name

through the flower morning glory flower

and people would throw stuff in and.

Overtime all the junk that

was thrown in clogged the.

The inlet to the pool and the

pool temperature started to

decrease and not allowed.

Different types of bacteria to grow in

it and change the color of the pool.

Now it looks like a mini grand prismatic.

It's like a rainbow color.

They even tried to clean out morning glory.

They drained it.

The Park Service drained and they

vacuumed out as much stuff they could.

They got like hundreds of dollars

of coins out of the thing,

along with handkerchiefs and

all kinds of junk,

but it hasn't come back to that.


Perfectly blue color,

so people throwing stuff in and it

used to be a tourist attraction to throw.

So there's one called handkerchief pool,

which is not too far from Old Faithful Inn.

You would throw a handkerchief in and

it would disappear and then would come

shooting back up a few seconds later.

And so this was a thing that you did

you through your handkerchief and it

went into the pool, came back out.

Hey I got a thermal handkerchief or whatever.

That kind of stuff is done quite a

lot and and another great example.

There was a swimming pool at Old Faithful.

Can you believe this?

There was a thermal swimming pool like

a hot spring pool at Old Faithful from

the early part of the 1900s to the 50s.

The way they fed the pool was to

put a pipe up to solitaire E Geyser,

which is on the hill above Old Faithful

and to tap that water to go into the pool.

And when they did that,

they changed the way solitairy behave.

Now eventually they demolish the

pool and got rid of the pipe.

But Solitaire E still has not gone

back to the way it used to behave.

So yeah,

humans have absolutely impacted the

the system by throwing stuff in,

and in some cases like the the

the swimming pool,

the old faithful and I I was I was

pretty shocked when I was walking

around with one of the Rangers

and she pointed to this very flat

area near the Firehole River City.

That's where the pool used to be.

What pool? Yeah.

That that way, then that's a real thing.

We wrote a caldera chronicles about that.

If you want to see some photos of

what the pool looked like actually

look like a pretty nice place,

but still crazy to think that there's

a pool right next to the faithful.

Yeah, no kidding.

My goodness. Well, Mike,

thank you so much for your talk tonight.

I mean, it was absolutely fascinating.

You answered so many

questions from our audience,

so I know that they appreciate it very much.

My pleasure if anyone has any questions

that that you weren't able to get to,

you can feel free to just send an

email and I'm more than happy to.

I'm always happy to talk Yellowstone.

Yeah, no, that's right.

It's at for those of you out there.

It's Yvo webteam at USGS Gov,

so we have it up there and again,

thank you so much and I also

want to thank all of you out

there who joined us tonight.

Mike's lecture will be available later

for on demand viewing on our website at LS and.

Again, we hope you can come

back next year, January 27th,

2022 at 6:00 PM Pacific Time to hear

Thomas Edwards four species here,

species there and species species

everywhere until next time.

Goodbye for now.