Caldera Chronicles

Caldera Chronicles is a weekly article written by U.S. Geological Survey Yellowstone Volcano Observatory scientists and colleagues.


Filter Total Items: 219
Date published: September 6, 2021

Silver Gate—the Mammoth Terraces of yesteryear!

Just south of Mammoth Hot Springs, near the north entrance of Yellowstone National Park, lies a jumble of white/gray rock known as the Hoodoos or, more formally, Silver Gate.  The origin of this deposit is a quintessential tale of the dynamic nature of Yellowstone.

Date published: August 30, 2021

Locating earthquakes in the Yellowstone region

Ever wonder how seismologists determine the location of an earthquake in Yellowstone?  It’s an intricate process, but thanks to experienced scientists, up to thousands of earthquakes are located in the Yellowstone region every year!

Date published: August 23, 2021

Volcano deformation: What and why?

The ground surface at Yellowstone goes up and down.  Since 2015 the caldera has been going down at a rate of about 2–3 cm—about 1 inch—per year, but during 2004 –2010 the caldera uplifted at a similar rate. What causes these ups and downs? Well…it’s complicated…

Date published: August 16, 2021

Borehole instruments: The hidden component of geophysical monitoring in Yellowstone

When it comes to data, Yellowstone is a geophysicist’s dream. There is continuous activity from earthquakes, geysers, and of course, the volcano itself. A keen eye may be able to spot one of the park’s numerous GPS or seismometer stations hard at work, but some of the park’s data collectors are buried deep within the Earth, hidden from sight in boreholes.

Date published: August 9, 2021

Where is the volcano?

Visitors to Yellowstone ask a lot of questions! So how do park rangers answer when they are asked, “where is the volcano?”

Date published: August 2, 2021

Relics of past earthquakes: How the 1959 Hebgen Lake M7.3 earthquake may continue to influence Yellowstone seismicity today

The M7.3 Hebgen Lake earthquake in 1959 is one of the two the largest recorded earthquakes in the entire Intermountain West of the United States.  We might still be seeing aftershocks from that event in what today is the most seismically active area of the Yellowstone region.

Date published: July 26, 2021

“Land of the burning ground”: The history and traditions of Indigenous people in Yellowstone

We sometimes think of Yellowstone as an untouched landscape, but humans have been present in the area for over ten thousand years!  The history and traditions of Indigenous people in Yellowstone are as rich as the landscape itself.

Date published: July 19, 2021

Yellowstone’s sibling in the southern hemisphere: Taupō, New Zealand

Yellowstone is not the only large caldera system in the world.  Indeed, caldera systems can be found all over the planet!  In New Zealand, the Taupō caldera system shares many similarities with Yellowstone—a history of large eruptions, geysers and hot springs, and even earthquake swarms and ground deformation, some of which might be related to magmatic intrusions.

Date published: July 12, 2021

An outlier of Yellowstone's thermal areas: the travertine of Mammoth Hot Springs

Early explorers during the separate Washburn, Hayden, and Hague expeditions of the 1870s were astonished by the massive terraces and pools of hot-spring limestone, better known as travertine, at Mammoth Hot Springs—a chemical oddity that is quite different from other Yellowstone thermal areas.

Date published: July 5, 2021

The long journey of water from Yellowstone’s hot springs and geysers to different oceans

Yellowstone’s hot spring waters ultimately flow for thousands of miles before entering the ocean. But waters enter two different oceans—the Gulf of Mexico and the Pacific Ocean.

Date published: June 28, 2021

The day that Porkchop Geyser exploded

Small hydrothermal explosions—steam blasts—are common at Yellowstone, occurring every year or two.  Most happen in the backcountry and are not observed by people.  In 1989, however, Porkchop Geyser blew up right in front of several observers on an otherwise sunny September afternoon.

Date published: June 21, 2021

What causes earthquake swarms at Yellowstone?

Earthquake swarms are common at Yellowstone, but why do they occur?  Are they driven by magma migration?  Water?  Steady creep along faults?  All three are possibilities, and tracking the style of the earthquakes can reveal the causes.