Monthly update of activity at Yellowstone Volcano for August 1, 2022 from Mammoth Hot Springs

Mike Poland, scientist-in-charge of the Yellowstone Volcano Observatory, describes activity at Yellowstone in this monthly update for August 1, 2022. 

The August 1 update comes to you from beautiful Mammoth Hot Springs in Yellowstone National Park. Tens of millions of years ago, this area was a shallow inland sea. The bedrock geology includes sandstones and slates, and even limestones composed of the shells of small marine organisms that accumulated over time. This area is also a zone of persistent hydrothermal activity and faulting, so hot fluids from the Yellowstone caldera migrate upward, interact with marine sediments, and pick up calcium carbonate. When the fluids get to the surface, the calcium carbonate is deposited, creating beautiful terraces. Mammoth is considered a travertine hot spring, which is different from the neutral chloride hot springs observed around Old Faithful, and the acid sulfate hot springs typified by Mud Volcano. These hot springs will be explored in the next two monthly updates.

During the month of July, there were 59 located earthquakes (maximum magnitude M3.1). Seasonal uplift detected by the GPS network continues due to groundwater accumulation. There were no water eruptions of Steamboat Geyser in July. Yellowstone remains at normal, background levels of activity.