Seismic Activity in Yellowstone National Park

Yellowstone National Park extends from Wyoming into parts of Idaho and Montana and is considered to be the hotbed of hydrothermal activity in the United States. The park is home to a diverse array of geysers, hot springs, and fumaroles and is considered to be one of the most seismically active areas in the US. Check out the National Park Service for official information on Yellowstone.Yellowstone's presence of magmas, partial melts, and hydrothermal activity, coupled with its underlying fault lines, make it a popular site for earthquakes. Over 32,000 earthquakes have been recorded in and near the park from 1975 to 2009. About 1,000 to 3,000 earthquakes occur each year around the park, but few are strong enough to be felt. Yellowstone's subsurface temperatures are high, which weakens bedrock, making it less likely to rupture. Yellowstone Net: Yellowstone National Park Earthquakes features an overview on earthquake information.  Earthquakes of Yellowstone: 1973 - 1996 describes every quake to occur in the park during this time period.

Even though most earthquakes are small, there have been a few notable earthquakes in the park's past. In 1959, west of the park near Hebgen Lake, an earthquake of a magnitude (M) 7.5 occurred. It caused a tidal wave that rushed over the dam which resulted in a landslide that killed 28 people. It caused 11 million dollars in damage. California State University, San Bernardino Geology Department provides an overview and pictures of this tragic event.

In 1975, a M 6.5 earthquake occurred near the Norris Geyser Basin that was felt throughout the area. The quake created two new geysers, downed one chimney, and created cracks in a parking lot. U.S. Geological Survey describes this historic earthquake. In late December 2008 and early January 2009, there was a swarm of earthquakes—813 total—reaching up to M 3.9. Scientists paid close attention to these quakes since frequency of earthquakes are often—but not always—a sign of an impending volcano eruption. Yellowstone Volcano Observatory describes this swarm. Earthquakes are not just a recent occurrence. Yellowstone National Park has a long history of earthquakes. The earliest account of earthquake activity in the park was recorded in 1872 by Ferdinand Hayden, who had camped in the park. He felt so many earthquakes that he referred to Yellowstone as “Earthquake Camp.” Bob Smith has conducted thorough research on Yellowstone earthquakes since 1970 and is currently the director of the Yellowstone Seismic Network. Even though earthquakes abound in the park, Yellowstone is generally safe for travel. Scientists have no evidence that a volcano eruption is imminent, especially since geological activity has remained somewhat constant in the past 30 years. Yellowstone National Park: Volcano Questions and Answers addresses any safety issues that you may have pertaining to the geothermal conditions of the park. There are many resources available that monitor daily conditions at the park so you can check the frequency of earthquakes before you arrive. Yellowstone Volcano Directory monitors volcanic and earthquake unrest and displays the current volcanic alert level and a monthly summary of conditions. The University of Utah's Seismograph Station features a seismic map that is updated every five minutes within an earthquake—or once every hour. There is no way to plan ahead to completely avoid earthquakes at Yellowstone National Park. Besides monitoring current conditions, you can arm yourself with knowledge of what to do if an earthquake occurs. Generally, it's best to be outdoors in a tent, away from buildings and utility wires. Make sure to pack flashlights, a battery-powered radio, and spare batteries. Yellowstone County, Montana's government site provides tip on how to be safe during an earthquake.