Yellowstone earthquake activity is currently at elevated levels compared with typical background activity, the Yellowstone Volcano Observatory reports in its monthly update for July 2017.
During July 2017, the University of Utah Seismograph Stations, responsible for the operation and analysis of the Yellowstone Seismic Network, reports 528 earthquakes were located in the Yellowstone National Park (YNP) region. The largest event was a minor earthquake of magnitude 3.6 on July 18, at 20:31 UTC (14:31 MDT), located about 14.5 km (9 miles) north northeast of West Yellowstone, MT. The earthquake was reported felt in the town of West Yellowstone, MT. This earthquake is part of a continued energetic sequence of earthquakes in the same area that began on June 12, 2017, YVO reports.
July seismicity in Yellowstone was marked by the ongoing seismicity ~9.6 km (6 miles) north of West Yellowstone, MT where an energetic swarm added an additional 475 earthquakes in July to the 1028 earthquakes in June.
The swarm includes the largest event of the month on July 18 (magnitude 3.6). Swarm activity for July consists of two earthquakes in the magnitude 3 range and 40 earthquakes in the magnitude 2 range. Including the events from last month beginning on June 12, total swarm seismicity includes one earthquake of magnitude 4.4, seven in the magnitude 3 range, and 112 earthquakes in the magnitude 2 range.
Earthquake sequences like these are common and account for roughly 50% of the total seismicity in the Yellowstone region.
Yellowstone earthquake activity is currently at elevated levels compared with typical background activity.
Monitored locations within the Yellowstone Caldera show minimal ground deformation change this month. Uplift north of the caldera, centered near the Norris Geyser Basin continues at a low rate. Behavior is similar to the past several months.
Current deformation patterns at Yellowstone remain within historical norms.