Emergency fix at a Yellowstone monitoring site (Yellowstone Monthly Update October 2025)

The Yellowstone caldera is vast – 45 miles across by 30 miles wide. You could fit over 60 islands of Manhattan in this area. There are deep canyons, like the one on the Yellowstone River, that reveal a complex geologic history. And, forested landscapes and features remind us that this special place is ever-changing.

The broad expanse of the caldera presents a challenge for monitoring seismic, volcanic, and hydrothermal activity. Where should monitoring stations go? Sometimes the best locations are close to roads. Sometimes they are in remote areas of the park.

The White Lake GPS station is in a remote area of the park. It is on the Sour Creek resurgent dome within Yellowstone Caldera. This is a raised area of the caldera floor that formed shortly after the last massive explosive eruption, when the ground was pushed upward by magma accumulating beneath the surface. Since 2015, the dome has been subsiding or sinking.

During the summer of 2024, the White Lake station went offline. The larger network of dozens of GPS stations in the region, including others on the Sour Creek dome continued to collect data, but repairing the White Lake station was important as it has a very long history and is located near the core of the dome.

The site requires a helicopter to access, and there hadn't been a chance to visit until September 2025. That's when a field team from the USGS and the EarthScope Consortium flew to the site to conduct repairs. The engineers found that water had corroded the antenna cable, so that had to be replaced. And in addition, they took the opportunity to perform some upgrades. They added weather sensors and also converted the communications from an older radio link to a new cellular system. This will allow for a stronger connection and the ability to stream higher rate data if needed.

The White Lake GPS station is now back online, with data flowing once again, and the data indicate that the subsidence of the caldera has continued, following the trend of the past decade.

During the month of September 2025, the University of Utah Seismograph Stations, which monitors and operates the Yellowstone seismic network, located 85 earthquakes. The largest was a magnitude 3.3 on September 28, that occurred just to the south of Mammoth Hot Springs. Deformation trends (subsidence) continue. Steamboat Geyser had minor activity but no major water eruption. Valentine and Guardian Geysers, within Norris Geyser Basin, have been erupting since August and a big fumarole opened in the Mud Volcano area. Yellowstone Volcano remains at normal, background levels of activity.