Michael Poland

Tuff Cliff, located north of Madison Junction in Yellowstone National Park, is one of the best-known exposures of the Lava Creek Tuff and has long been cited as a classic example of member A of that deposit.  USGS photo by Mike Poland, September 24, 2026.

Black Pearl Geyser in Biscuit Basin, Upper Geyser Basin, Yellowstone National Park.  USGS photo by Mike Poland, September 22, 2026.

YGH monitoring station near Geyser Hill, Upper Geyser Basin, Yellowstone National Park.  Infrasound sensors sit under the brown "hats" that serve as wind screens, and a seismometer is buried nearby.

View from September 11, 2026, at 3:02:16 p.m.

Acoustic signals recorded at infrasound arrays (red inverted triangles) YBB (in Biscuit Basin) and YGH (near Geyser Hill), in Upper Geyser Basin, can be used to determine the direction from which low-frequency acoustic signals originated, also called the backazimuth.  This example is from 9:14 p.m.

View from a research camera installed at Biscuit Basin near the site of seismic, infrasound, and GPS monitoring. The camera has a view of Black Diamond Pool, where a hydrothermal explosion occurred on July 23, 2024, as well as of the area north of the pool where another small explosion occurred on June 13, 2026.  Camera images are updated every 15 minutes

Camera installed at the Biscuit Basin monitoring site. The camera is near the top of a small tower that holds a weather sensor and solar panel that powers nearby seismic and acoustic sensors.  The solar panel that powers the camera is located on the ground at the base of the tower.  USGS photo by Mike Poland, July 22, 2026.

Black Sand Pool, in Yellowstone National Park's Upper Geyser Basin.  The hot spring is known for it's thumping behavior, which occurs every few minutes due to collapse of bubbles within the spring.  The thumping is strong enough to be heard and felt by anyone nearby.  USGS photo by Mike Poland, July 21, 2026.

Screen capture showing the view from the Biscuit Basin research and monitoring camera at 05:09:54 a.m. MDT on June 13, 2026.  Black Diamond Pool is in the foreground, and a steam plume in the upper right marks the occurrence of a small hydrothermal explosion behind (to the north of) the pool.

Infographic giving earthquake, deformation, thermal emission, and geyser statistics for the Yellowstone region for the year 2024.  The graphic accompanies the Yellowstone Volcano Observatory 2024 annual report, freely available online at https://pubs.usgs.gov/publication/cir1566.

Front cover of the Yellowstone Volcano Observatory 2024 annual report, which includes a summary of earthquake, deformation, and geyser activity, as well as research investigations and other information. The report is freely available online at https://pubs.usgs.gov/publication/cir1566.