Earthquake Journal Entry

Quake Swarm Hits Yellowstone (January 28, 2010)

A swarm of more than 1,000 small earthquakes of up to magnitude 3.8 shook the northwestern corner of Yellowstone National Park, near the Wyoming-Montana border. Ten of the quakes registered over magnitude 3.0. The quakes were all centered in a tiny area 9 miles (14 kilometers) east of the town of West Yellowstone and 10 miles (16 km) west of Old Faithful, the park's most famous geyser and biggest tourist attraction. No injuries or damages were reported.

Earthquake swarms are fairly common in Yellowstone. About 80 of them have been recorded since 1995. Scientists don't think the recent swarm is a sign the park's long-sleeping volcano is about to wake up from its slumber. There's no sign magma is stirring below Yellowstone's huge caldera. It's more likely the quakes are the result of tectonic shifts in the slabs of Earth's crust the park is sitting on.

Yellowstone lies in a seismically active region known for its geothermal activity. The park lies within a huge caldera, the collapsed remains of a volcano that last erupted 70,000 years ago. Magma that once filled the volcano now lies just five to ten miles underground. Heat from the magma provides energy for Yellowstone's popular geysers, fumaroles, hot springs, and mud pots.

Not all of Yellowstone's earthquakes have been small or harmless. In 1959, a magnitude 7.5 quake at Hebgen Lake just west of the park touched off deadly landslides, killing 28 people.