In this period of relative eruption-level calm, here is a monthly update from the Yellowstone Volcano Observatory, where the current Volcanic Alert Level is NORMAL and the Aviation Color Code is GREEN.
August has been a spectacular month for the Yellowstone Geysers.
Steamboat Geyser erupted five times during the month, on August 3, 9, 14, 20 and 26, bringing the total number of eruptions for the year to 34.
Additionally, on August 26, Giantess Geyser, in the Upper Geyser Basin not far from Old Faithful, erupted for the first time in over six and a half years! Geyser activity like this is common and does not reflect deeper volcanic processes, but it is a spectacular sight to see.
Seismicity level: In August 2020, the University of Utah seismograph stations, responsible for the operation and analysis of the Yellowstone seismic network, located 82 earthquakes in the region of the National Park of Yellowstone. The most significant event was a minor magnitude 2.6 earthquake located 7 miles west of Old Faithful, Yellowstone National Park, on August 20 at 11:12 p.m. PT. .
A small swarm of 12 earthquakes occurred about 12 miles north-northeast of Old Faithful on August 18. The largest swarm event was a magnitude 0.9 micro-earthquake on August 18 at 4:07 a.m. PST.
Earthquake sequences like these are common and account for about 50% of the total seismicity in the Yellowstone area.
Yellowstone's seismic activity remains at background levels.
The rates and styles of deformation in Yellowstone, recorded by continuous GPS stations, have not changed significantly for many months.
The subsidence of the Yellowstone caldera, ongoing since 2015, continued at an average rate of 2-3 cm (about 1 inch) per year.
In the Norris Geyser Basin area, little deformation has been detected by a nearby GPS station since early 2020.
Sources: YVO, Yellowstone for ever