Images

Map of the Heart Mountain slide block. From Mitchell et al., 2015 ("Catastrophic emplacement of giant landslides aided by thermal decomposition: Heart Mountain, Wyoming." Earth and Planetary Science Letters 411: 199-207), modified from Anders et al. (2010).

(Left) Sample of the Pitchstone Plateau rhyolite flow, which erupted about 72,000 years ago, making it is the youngest rhyolite at Yellowstone. The blocky white crystals in this sample are the mineral sanidine, whereas the rounded crystals are quartz.

Gas collection from a bubbling source within Pelican Creek, Yellowstone. Inverted funnel placed over gas source, gas travels through tubing into evacuated/vacuum glas flask to be analyzed in lab.

Gas flask sampling at West Astringent Creek, Yellowstone. Open tube with attached gas chamber inserted into ground, gas travels through tube into vacuum flask being held by scientist.

Lidar coverage of the Hebgen and Red Canyon faults collected in 2014. Magenta lines show fault scarps mapped by USGS geologists shortly after the 1959 earthquake. Yellow lines show fault scarps interpreted from lidar data 55 years after the earthquake.

Lava Mountain, Wyoming.  (A) View from Dubois, WY, in the Wind River basin looking northwest ~30 km toward Lava Mountain.

Schematic cross section of the magmatic and hydrothermal systems underlying Yellowstone Caldera, showing magmatic volatiles emitted during crystallization of the rhyolitic magma and/or from basalt intrusions or convection, and the hypothesized relation with earthquake swarms on the caldera margins.  The exsolved fluids accumulate at lithostatic pressures in the

Frosted trees in the Fairy Falls area of Yellowstone National Park near the Firehole River.  National Park Service photo by Annie Carlson, 2014.

Thermal infrared image of a portion of Norris Geyser Basin, Yellowstone National Park, acquired from an airborne thermal survey in October 2014.  Warm colors indicate higher temperatures, and cooler colors are lower temperatures.

The contact (red arrow) between Huckleberry Ridge Tuff ignimbrite members A and B is marked by a time break of probably weeks to a month or so.

A mud pot in the Obsidian Pool Thermal Area, near Mud Volcano. The large amounts of suspended sediment make the thermal water much more viscous than pure water. Photo by Shaul Hurwitz, September 2014.

Example model output of possible ash distribution from a month-long Yellowstone supereruption. Results vary depending on wind and eruption conditions. Historical winds for January 2001 used here.

Images of a) the southern Teton Mountains and b) the northern Teton Mountains as seen from the Bridger-Teton National Forest. USGS photos by Stanley Mordensky, August 2014.

Beryl Spring's strongly boiling blue pool is about 8 m (25 ft) wide and contains high-chloride liquid water with a near-neutral pH. Immediately behind the pool is a loud, hissing fumarole producing a white cloud of steam. USGS Photo by Pat Shanks, 2002.

The left axis shows the number of earthquakes per week. The right axis is the total cumulative number of earthquakes, which means it has to always increase. It increased a lot in the period 1996-2003 when there was a period of uplift near Norris.

Station map showing seismograph stations used in the location of the M4.8 earthquake that occurred near Norris Geyser Basin on March 30, 2014.  The yellow star shows the earthquake epicenter.  Red triangles represent seismograph stations with a P-wave arrival pick.  Green triangles represent seismograph stations with both a P-wave and a S-wave arrival

Seismograms of the magnitude 4.8 earthquake that occurred in Yellowstone on March 30, 2014, as recorded by seismometers at station YNR near Norris Geyser Basin.  Top: Seismogram recorded on the accelerometer, which stayed on scale during the shaking.  Bottom: “Clipped” seismogram recorded on the broadband seismometer, which went off scale during the shakin

Telemetry system of the Yellowstone Seismic Network operated by the University of Utah Seismograph Stations.  Black arrows show analog telemetry and pink arrows show digital telemetry.  The green line is the boundary of Yellowstone National Park.

Record section showing horizontal component seismograms from stations in the Yellowstone region from the M4.8 earthquake that occurred near Norris Geyser Basin on March 30, 2014.  The vertical blue dashed line represents the origin time of the earthquake at 12:34:39.16 UTC.  The red line represents the P-wave arrival with a velocity of ~5.7 km/s.  The

3-component seismograms from station YHB for the M4.8 earthquake that occurred near Norris Geyser Basin on March 30, 2014, and showing the P-wave arrival pick (red) and the S-wave arrival pick (green) as determined by UUSS analysts.  The vertical blue dashed line represents the origin time of the earthquake at 12:34:39.16 UTC.

Time history of Yellowstone Caldera uplift (black line) and subsidence patterns along with quarterly catalog earthquake counts (blue bars). Note that large swarms in 1985 and 2010 accompany uplift to subsidence of caldera. The vertical deformation on the right axis was measured at the Sour Creek (SC) dome in the eastern part of the Yellowstone Caldera.