Images

Serapeum, a Roman Marketplace in Pozzuoli, Italy, records deformation of Campi Flegrei caldera over two millennia.

Dragon’s Mouth in the Mud Volcano Area of Yellowstone National Park.

Mushroom Pool, Lower Geyser Basin, Yellowstone National Park.

Hot spring waters with relatively high dissolved element concentrations on the floor of West Thumb, Yellowstone Lake. Image acquired by the Global Foundation for Ocean Exploration ROV Yogi on August 7, 2018.

Fishing cone, a hot springs on the floor of Yellowstone Lake. The hot spring rim sits at lake level.

Sensor deployed in the Deep Hole, east of Stevenson Island to monitor long-term temperature and chemical variations in an active vent. Image acquired by the Global Foundation for Ocean Exploration ROV Yogi on August 4, 2018.

A sensor data logger recovered from the floor of Yellowstone Lake in the Deep Hole area in 2018 shows signs of melting due to unexpectedly high temperatures in sediments up to ~3 ft (1 m) away from an active hydrothermal vent. Image acquired by the Global Foundation for Ocean Exploration ROV Yogi on August 4, 2018.

Sensor (top), deformed battery/electronics package (bottom), and titanium sheath (left) following recovery from vent location A in teh Deep Hole area on the floor of Yellowstone Lake.

Sensor (left) and battery/electronics package (right) at vent location A in the Deep Hole area of Yellowstone Lake.  Photo was taken immediately before recovery from the lake floor. Notice the battery/electronics package slightly submerged in sediment.

Spectrogram and wind data from stations on Stevenson Island for June 30, 2018. Warm colors in the spectrogram correspond to stronger seismic energy compared to cool colors. The ~1-second-period lake-generated microseism (outlined by the black box) that was generated on this day is correlated with elevated wind speeds (red circles) as a storm passed by overnight.

River Styx, Mammoth Hot Springs, Yellowstone National Park. This thermal feature is actually a subterranean hot water creek that likely collects water discharged from Mammoth Hot Spring pools that, after cooling and outflowing from vents, tends to disappear back underground through the porous travertine.

View of Lower Geyser Basin, with Fountain and Clepsydra Geysers in eruption, looking south towards Fountain Paint Pots. The vegetation in the photo is indicative of vegetation throughout much of Lower Geyser Basin—open grassland maintained by hot ground with patches of lodgepole pine.

Steamboat Geyser in the water-phase of an eruption on June 4, 2018, Norris Geyser Basin, Yellowstone National Park.

Steamboat Geyser in the steam-phase of an eruption on June 4, 2018, Norris Geyser Basin, Yellowstone National Park.

A nodal seismometer can be easily deployed for a month in a closely spaced array of tens of instruments. Arrays have been installed at Yellowstone National Park to map subsurface of geyser basins.

Large hydrothermal explosion craters shown with black dot and leader plus associated breccia deposits in Yellowstone National Park (locations from

Red circles represent all seismicity and blue circles represent earthquakes as part of earthquake swarms. The size of the circles is scaled to the magnitude of the earthquake. The 630,000 year old Yellowstone caldera is shown as a bold black line within Yellowstone National Park. Mapped faults are shown as light gray lines.

Doublet Pool, fringed by geyserite, in the Upper Geyser Basin of Yellowstone National Park. National Park Service photograph by Jacob Frank.

The head of an immature wetsalts tiger beetle at the entrance to the burrow it dug. Photo by Robert K. D. Peterson, 2017.

Time series of vertical displacements during April–October 2017 at four GPS stations (LAK1, LAK2, LKWY, and SEDG) on the north side of Yellowstone Lake. Downward trends indicate subsidence and upward trends show uplift. Uplift “spikes” in late September are related to inclement weather and do not show true deformation. Error bars are one standard deviation.

Map showing volcanoes that formed at the leading edge of the Yellowstone hotspot in the past several million years.  (A) Map of northwest Wyoming, eastern Idaho, and southern Montana (modified from Brueseke et al., 2017, https://doi.org/10.1130/GES01553.1).  Upper Wind River Basin (UWRB) is depicted by dashe