The October 2017 seismicity in Yellowstone was marked by the ongoing but waning earthquake swarm north of West Yellowstone, MT, contributing 60 earthquakes to the existing catalog of 2 475 events located in the area since June, the Yellowstone Volcano Observatory reports in their monthly update released November 1, 2017. During October 2017, the University of Utah Seismograph Stations, responsible for the operation and analysis of the Yellowstone Seismic Network, reports that 111

earthquakes were located in the Yellowstone National Park region. The two largest earthquakes of the month both registered magnitude 2.2 and occurred on October 30 and 31, one about 11 km (7 miles) northeast of West Yellowstone, MT, at 09:29 UTC (03:29 MDT) on October 30, and another about 5 km (3 miles) north-northeast of West Thumb, WY, at 05:12 UTC on October 31 (23:12 MDT, October 30). October seismicity in Yellowstone was marked by the ongoing but waning swarm north of West Yellowstone. CONTINUE