Monday, March 31, 2014

Yellowstone Caldera Hit By Mag 4.8 Quake

Yellowstone Caldera was struck by a magnitude 4.8 quake on March 31st, the largest quake in the area in over 34 years. The quake was centered in an area of continuing uplift that has been documented since the mind-90's, and is most likely related to a small intrusion of magma at depth. This quake does not increase the risk of an eruption at Yellowstone, although the volcano is still very closely monitored as its potential for a nation-killing eruption is very high.

It has been a busy couple of years for Yellowstone. Earlier last year, a geyser that had not erupted in over 8 years had some activity, and earthquake swarms have been slightly more numerous than 'normal'. Again, there is no indication that any of this activity is pointing to an imminent eruption. The current episode of D/I (deflation/inflation) is still well within historical norms since monitoring began, and is not out of character for the volcano. While rare, Yellowstone has produced quakes in the larger magnitudes, around 6.0, in the past.

Screenshot of Google Earth with USGS overlay showing center of quake swarms.

Yellowstone caldera is one of the most researched volcanoes on the planet. It is used as a laboratory of sorts for all kinds of scientific analysis and testing of technology from seismic wave detection, to imaging of magma chambers. It was recently discovered that Yellowstone's magma chamber is 2.5 times larger than previously thought, however other studies have now suggested that the volcano may be 'dying' as not only is the magma slowly cooling, but the last 'super eruption' of the volcano was more than 600,000 years ago, and its most recent was barely a 'blip' on the radar, some 70,000 years ago.

Currently Yellowstone is classified as active, and has the largest concentration of geysers and hot springs in the world. There is some debate within the scientific community as to whether it is 'overdue' for an eruption, but the recent discovery that it may be cooling might throw some cold water on that idea. It would take a very large injection of fresh magma from the mantle plume to actually initiate an eruption, and this seems quite unlikely at this time. Hotspots do not live forever, as has been seen with ones like the Bermuda Hotspot, which stopped at (you guessed it) the Bermuda islands (or so it has been theorized). It could be that Yellowstone is in it's long, drawn-out death throes, but will still give us a jolt every now and again. Only time will tell, and most likely, none of us will be around when we finally get that answer.

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