Do Yellowstone Earthquakes Foretell Yellowstone Volcano Eruption?

It is not unusual for there to be small earthquakes in the Yellowstone Park area, however the recent spate of Yellowstone earthquakes are different. The University of Utah publishes a map of recent Yellowstone earthquakes online. The map currently shows 146 earthquakes in the Yellowstone National Park area within the last week, most of them underneath the ancient Yellowstone volcano. Many of them over 3.0 on the Richter scale and the strongest reaching a 3.9 reading. For reference, an earthquake with a strength of 4.0 is capable of causing moderate damage.

Yellowstone Earthquakes centered under Yellowstone Volcano

These Yellowstone earthquakes are not powerful, but there are a lot of them occurring in a very short period of time. Yellowstone National Park is the home of the Old Faithful Geyser which derives its heat from a shallow, five to ten mile deep pool of magma that lies below Yellowstone. The Yellowstone caldera is, in fact, the remnants of a very large volcanic event that occurred hundreds of thousands of years ago. The area is still very geologically active and, according to the University of Utah's earthquake center, is the site of 1000-2000 small earthquakes every year, but they say, this week's activity is much higher than average.

Yellowstone Supervolcano is Largest Volcano in the US

With all the shaking going on in Yellowstone Park, we can't help but think of the possible effects if the supervolcano under the park were to erupt again. The last time the Yellowstone supervolcano erupted was approximately 640,000 years ago, says Larry Hanlon in his article "America's Explosive Park" on the Discover Channel website. He also notes that the last time the Yellowstone volcano erupted, it was about 8000 times more destructive than the Mount St. Helens eruption. It has, he says, the potential to be even more powerful than that. If these Yellowstone earthquakes are a precursor to another eruption, the damage would almost certainly be more catastrophic than we can imagine. Aside from the destruction force of the explosion, the tremendous amounts of ash that would be released into the atmosphere would certainly have a dramatic, if temporary, effect on the Earth's climate. While it would not stop global warming in the longer term, we might expect the ash to block enough sunlight globally to cause a year or two of the coldest weather on record. Not to mention that the Eastern half of the United States would likely be covered in abrasive volcanic ash as it fell from the sky.

Cause of Recent Yellowstone Earthquakes Still Unknown

At present, it is not clear if these recent Yellowstone earthquakes are the result of existing, but undiscovered fault lines in the area, or if they are related to increased geothermal activity of the Yellowstone volcano. While the possibility of a major eruption at Yellowstone remains extremely unlikely, the volatility of the area reminds us how marvelous and fragile some of our country's natural wonders can be. Even without a major eruption, places like Old Faithful could be disrupted by a minor shift in the geothermal conditions at Yellowstone, just as natural aging and the forces of the weather caused the collapse of the Wall Arch earlier this year at Arches National Park in Utah.

Sources:

O'Hanlon, Larry, "America's Explosive Park", retrieved on December 30. 2008 from dsc.discovery.com/convergence/supervolcano/under/under.html

University of Utah Earthquake Information Center: seis.utah.edu/EQCENTER/eqcenter.htm

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