Earthquake Swarm at Yellowstone Supervolcano: Update

January 01, 2009
James Pethokoukis

So what is the latest with the ongoing earthquake swarm at the Yellowstone supervolcano caldera? Here is my just-completed email chat with Dr. Jacob Lowenstern of the U.S. Geological Survey, top scientist at the Yellowstone Volcano Observatory:

How would you characterize the recent level of seismic level? Terms like "swarm" are pretty alarming. How would place this level of activity in historical context to what the USGS/YVO have tracked before?

Lowenstern: Swarm refers to seismicity when there isn't a typical mainshock/aftershock sequence. In other words, the events are more similar in size. Swarms are very common at Yellowstone. This one is clearly bigger than normal, and is the largest since 1985. There were also some large swarms in the 1970s, but the seismic network was much cruder at that time and we weren't able to locate earthquakes as well. the rest