Swarm of Yellowstone Quakes Baffles Scientists
Posted on December 31, 2008 Comments (1)
“There doesn’t seem to be anything to be alarmed about,” Vallie said. Smith said it’s difficult to say what might be causing the tremors. He pointed out that Yellowstone is the caldera of a volcano that last erupted 70,000 years ago.
Yellowstone has had significant earthquakes as well as minor ones in recent decades. In 1959, a magnitude 7.5 quake near Hebgen Lake just west of the park triggered a landslide that killed 28 people.
So far the most powerful quake over the last few days has been one at 3.8 on the Richter scale. An earthquake of 4.0-4.9 “Noticeable shaking of indoor items, rattling noises. Significant damage unlikely.” The Richter scale is a logarithmic scale, meaning a measure of 4.0 is 10 times as powerful as 3.0 quake, and 5.0 is 100 times more powerful than a 3.o quake.
Related: Scientists Chart Record Rise in Yellowstone Caldera (2007) – Yellowstone Is Rising on Swollen “Supervolcano” – Live earthquake measurements at Yellowstone – Quake Lifts Island Ten Feet Out of Ocean – Wabash Valley, Illinois Earthquakes