USGS Scientist Talks About Lava Lake in Halema‘uma‘u Crater
USGS–Hawaiian Volcano Observatory research geologist Matt Patrick talks about the lava lake in the Halema‘uma‘u Crater at the Kīlauea Volcano (Hawaii). Dr. Patrick describes the eruption that created the lava lake and points out features of the lake including moving crustal plates, gas bursts, spatter and collapse scars on the crater rim. Dr. Patrick also discusses hazards near the lake, such as explosions and volcanic gases. This is a recording of the USGS Volcanoes Facebook Live event held on March 19, 2018, on the 10th anniversary of the summit eruption.
Location Taken: Hawaii Volcanoes National Park, HI, US
Narration, Matt Patrick.
Video by Liz Westby.
Video produced by Janet Babb.
[Wind noise throughout the video.]
Hi how’s that coming in?
So my name is Matt Patrick, I work for the Hawaiian Volcano Observatory – the U.S. Geological Survey. We’re here on the rim of Halema‘uma‘u Crater. Today is March 19, 2018, and this marks the 10-year anniversary of the summit eruption, which began of March 19, 2008.
Right behind me is the active lava lake in Halema‘uma‘u Crater and you can see just to the side of me, a little spattering. It’s just dying out. But spattering in the lake is very common.
We’re here today to make a quick visit to do daily measurements and observations. So one of the most important things that we track is the lake level and that is what I have the laser rangefinder here to do. And we also make general visual observations of the lake behavior.
Right now you see some of that spattering has died out but there is still some persistent spattering in the south part of the lake.
So if you look at the lake surface, it’s really interesting. It has these large, black crustal plates. And it’s hard to see, but the upwelling is in the north part of the lake, which is just in that direction there. And so the lava upwells in the north part of the lake and it flows toward the south where it sinks and presumable cycles downward. The spot where it sinks is commonly where the spatter is situated, although spattering can really happen on any area of the lake. It’s commonly in the lake margins.
What we’re standing on right now is actually a lot of Pele’s Hair, which are thin filaments of lava. Pele’s Hair is produced during the spattering activity. Basically, the spattering is large bubbles bursting–ejecting droplets of lava. The droplets have little tails and it’s the tails that form the Pele’s Hair.
So obviously, we’re here on the crater rim. One of the hazards in this general area is the hazard of explosive events. There have been a handful of explosions from the lake and they are triggered by large collapses of the crater walls. Basically, the crater walls you can see are fairly unstable, the collapses can fall into the lake and the lake is very gas-rich and frothy and when the rocks impact the lake they trigger a very violent explosion or ejection of gas and spatter. And so that is one of the reasons we have to wear protective gear like you see, we’re wearing helmets. Another hazard out here, obviously, is the gas. The lava lake is producing a lot of volcanic gas. And one of the hazards is sulfur dioxide emissions and that is why we have to wear gas masks out here. And of course we also just wear basic protective clothing like fire resistant clothing as well.
So, yeah, the weather is a bit marginal right now but I think it will hold.
General observations over the past day, the lake has been really steady. And that’s not surprising because over the last few years we’ve actually had fairly steady activity. The lake level does fluctuate a bit. But in general, the lake you see now is similar to what it’s been like over the past few years. One change though, is that this crater is enlarging. The crater walls are constantly collapsing in and then lake enlarges to fill that larger area–the larger volume.
And so what we have now is one of the largest lava lakes on Earth. But it is really unique in the sense that geologists are here every day, observing, and documenting the activity so we have a long detailed history of the lake activity.
So I guess the question is how did the lake come to be? Well, on March 19, 2008, we had a small explosion that followed several months of increasing seismic tremor and increasing gas emissions in late 2007 to early 2008. On March 19, 2008, we had a small explosion and that was associated with the opening of this new crater here, which we call the Overlook Crater.
Originally that crater was about 100 feet wide. And the lava, in the first couple of years, was very deep, about 200 yards below the floor of Halema‘uma‘u Crater. So over the past decade we’ve had lava rise into the crater and we’ve also had the crater enlarging quite a bit. Now it’s about, along this axis, it’s over 900 feet long. So beginning at 100 feet and enlarging to over 900 feet. And like I said, the lava was originally 200 yards or so below the floor of Halema‘uma‘u Crater and now it’s more like 30 yards below the rim there.
So you just saw some small minor bubble bursting in the lake surface. That’s kind of interesting because we often have these isolated bubble bursts in the north part of the lake and that corresponds with where the lava is upwelling. So those sporadic bubble bursts that you see might be bubbles rising up from the conduit that is feeding lava into the base of the lake.
So the lava is upwelling, as I said, in the north part of the lake and it’s traveling just a few inches a second and it takes about 30 minutes or so to cross the lake surface. So it’s hard to see but the lake surface is slowly migrating toward the south.
I’ll just step out of view so you can get a view of the lake.
So, I just want to repeat that we are here today in part because it’s the 10th anniversary of the summit eruption. Like I said, the summit eruption began March 19, 2008–that was the start of the summit eruption. This eruption has been going on for 10 years which obviously is a remarkable duration for a volcanic eruption. What is also remarkable is that this is only one of two long-term eruptions. We also have the Pu‘u ‘Ō‘ō eruption going on in the East Rift Zone. That has been going on for over 35 years.
And we often get a question of how are these eruptions connected? And that’s a really great question because Kilauea is really interesting and remarkable for the hydraulic connection that exists from the summit along the East Rift Zone. And this eruption, and the Pu‘u ‘Ō‘ō eruption 12 miles away, are both jointly fed by jointly supplied magma from the summit magma chamber that’s below us here at a depth of a couple of miles.
There is a question of how high is the lava? It’s about 30 meters below the rim there. And how hot is the lava? What you can see is that the surface has these large black crustal plates. And those crustal plates are obviously hot, but much lower than the actual magmatic eruption temperature. The plates themselves are a couple of hundred degrees Celsius, 200-300 degrees Celsius [400-500 degrees F] and that’s way lower than the eruption temperature of the lava just below the surface which is incandescent (that’s around 1100 degrees Celsius). So the surface cools really instantaneously to form this black skin. And you can see that the crust here, if you zoom in or look closely, you can see that the crust is actually semi-flexible. It’s more like a skin. It’s thin; probably just a couple of inches thick and it’s very hot. So it can actually bend and fold. You can get a sense of the bends and folds on the lake surface.
But these zones in between plates, these are spreading….
Hi USGS Volcanoes. We apologize for the little break in connectivity. We are down here on the rim after all. But we’re back, with Matt Patrick, from the USGS-Hawaiian Volcano Observatory.
So, right now, I just made a lake level measurement with the laser rangefinder. The lake is about 30 yards below the crater floor there. That’s been a typical level for the last several months.
I think we’re going to wrap up soon. But I want to mention the USGS video that’s on the USGS YouTube Channel and it’s a 24-minute video that gives a really nice overview of the summit activity and the summit eruption [https://youtu.be/gNoJv5Vkumk]. There are some really great views and really great clips in that video.
So, we are here basically, in part because of the 10-year anniversary of the summit eruption that started March 19, 2008. But, really we’re here to do our daily lake level measurements and daily observations.
We’re going to wrap it up. Thanks for tuning in and we’ll catch you later.
Okay, hello again. I guess we have a few more minutes. So, one thing that we can talk about is the crater floor here. So we are on the rim of Halema‘uma‘u Crater. And you can see in front of us, about 80 yards below us, is the crater floor of Halema‘uma‘u Crater. You can see in the foreground, you can see this dark area. These were overflows. So there was a time in mid-2015, when the lake rose up to the rim and began to spill over onto the floor of Halema‘uma‘u Crater. And it created these flows of shelly pāhoehoe. These flows cover about a quarter of the floor of Halema‘uma‘u Crater. The rest of the floor was formed from earlier eruptions in the 60s and 70s.
You’ll also see on the top of some of these overflows, some white blocks. And some are from explosions recently that deposited on top of the overflows. And there is also a little bit on the north rim, some spatter from a collapse about a week ago or so ago, that triggered a small explosion where spatter was deposited on the crater rim.
There is a lot of steaming in the distance on the crater floor. There are obviously a lot of hot cracks. Some of these are magmatic gases and you can actually see some sulfur deposits around these fumaroles. And some of it is just water vapor. There has been a lot of rain recently, so basically, much of the Kīlauea caldera floor, there has been a lot of steaming just from groundwater.
Ok, so we’re often asked what are we sensing here, what do we smell? Actually, I smell clean air because we deliberately chose to be on the upwind side of the plumes. So, you can see there is a lot of gas coming out. We deliberately chose this spot to avoid that. Still, occasionally, if you do walk by some of these fumarolic areas you’ll get a smell of sulfur. In general, we’re trying to avoid the gas right now.
So we just had a small bubble burst here in the north side of the lake again. They are these quasi-periodic bubble bursts that happen in the north part of the lake that corresponds with the area where the lava is upwelling. You can also see on the crater walls, there are these white patches, kind of lighter-colored patches. And those are recent collapses. And we talked about how the crater is expanding, it’s constantly enlarging and it enlarges through these large collapses. And these white patches are basically fresh collapse scars. These collapses happened in the last week.
And like I said, sometimes when these collapses impact the lake, they trigger spattering of some size and occasionally if the collapses are large enough, they’ll trigger an explosion where spatter can reach the rim of Halema‘uma‘u.
Okay, so I think our time is up now. We can’t stay too long for safety reasons. So we’re going to sign off for real this time. We finished what we needed to do. We did our lava lake measurement. We make our basic observations and I think we’re going to head back to the vehicle now. Thanks for tuning in and we’ll see you later.