The Yellowstone Plateau volcanic field developed through three volcanic cycles spanning over two million years and including two of the world's largest known eruptions.


The >2450 km3 (588 mi3) Huckleberry Ridge Tuff erupted about 2.1 million years ago, creating a large, approximately 75 km (47 mi) wide, caldera and thick volcanic deposits. A second cycle concluded with the eruption of the much smaller Mesa Falls Tuff around 1.3 million years ago. Activity subsequently shifted to the present Yellowstone Plateau and culminated 640,000 years ago with the eruption of the >10003km (240 mi3) Lava Creek Tuff and consequent formation of the 45 x 85 km (28 x 53 mi) caldera. Large volumes of rhyolitic lava flows (approximately 600 km3 (144 mi3) were erupted in the caldera between 180,000 and 70,000 years ago, distributed primarily along two north-south alignments of vents. No magmatic eruptions have occurred since then, but large hydrothermal explosions have taken place during the Holocene, including near Yellowstone Lake. Uplift and subsidence of the ground surface is centered on two uplifted regions (the Mallard Lake and Sour Creek resurgent domes). Large earthquakes occur just off the plateau along the nearby Teton and Hebgen Lake faults, the latter of which ruptured in 1959 (Ms = 7.5), causing considerable damage to the region. Yellowstone is presently the site of one of the world's largest hydrothermal systems including Earth's largest concentration of geysers.


Date published: December 6, 2021

Arsenic in Yellowstone’s thermal waters

Yellowstone’s thermal waters are more than just hot—they also contain a variety of elements, some of which are potentially toxic!  Arsenic is an example, but the concentrations of this element depend on the style of the thermal feature.  Perhaps paradoxically, acidic thermal features contain much less arsenic than neutral ones!

Date published: November 29, 2021

Why Have There Been So Many Earthquakes in Central Idaho?

Seismic activity in central Idaho has been elevated for the past 20 months. These earthquakes are aftershocks of a M6.5 earthquake that occurred on March 31, 2020—a classic example of a mainshock-aftershock sequence!

Date published: November 22, 2021

The largest landslide in the world

Yellowstone is well-known as one of the largest volcanic systems in the world. Few people know, however, that the largest-known subaerial landslide on Earth is located just next door.

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