Since December 26th, hundreds of small earthquakes have shimmied Yellowstone National Park.
Earthquake swarms are a collection of small earthquakes over a short space of time. These aren’t aftershocks of one primary, larger quake, they are quakes in their own right. Yellowstone National Park, located mainly in the state of Wyoming (stretching into Montana and Idaho), plays host to the Yellowstone Caldera, a volcanic hotspot where molten mantle rock bubbles to the surface. This activity creates hot springs and is the energy source of many geysers.
The last Yellowstone “supereruption” occurred 640,000 years ago, but there have been many smaller eruptions and lava flows since then; the most recent being 70,000 years ago.
Any earthquake in the largest volcanic system in North America will therefore cause excitement and a little concern, and these recent earthquake swarms are an oddity. Yellowstone is no stranger to earthquake swarms, but the recent frequency of events are unusual scientists say.
In an effort to track the swarms, I’ve stumbled across an interesting article where a numerical modelling package has been used to locate and simulate the earthquake swarm breakouts…
Using the Mathematica software, Arnoud Buzing decided to create an animation to track the recent strange Yellowstone behaviour. It’s not so much the tracking of the quakes I find most interesting, it is the apparent ease at which Buzing was able to download seismic data and overlay it onto geographical data. A superb effort.
On playing the animation generated (4.3MB .mov), it becomes very clear that Yellowstone is undergoing a rapid series of quakes focused under two primary locations.
Since this animation was generated, Yellowstone has continued to rumble and on Friday, three quakes surpassed the magnitude 3.0 mark. Although no damage or injury has been reported (these quakes are considered low-level), scientists are at a loss to understand what could be causing the tremors. For now, these swarms are interesting, but certainly not a huge concern yet.