Yellowstone is one of the largest known volcanoes in the world and the largest volcanic system in North America. The volcano is found above an intra-plate hot spot that has been feeding the magma chamber underneath Yellowstone for at least 2 million years.
The giant caldera is the product of large-scale collapse of the crust after 3 so-called ultra-Plinian or super-volcano eruptions - large explosive events that erupt several hundreds to few thousands of cubic km of magma. These eruptions took place 2.1, 1.3 and 0.64 million years ago.
Yellowstone is also the world's largest hydrothermal system. It contains 182 geysers, mud pools and fumaroles. The most famous feature in Yellowstone is Old Faithful Geyser.
Future super-volcano eruptions at Yellowstone? Yellowstone's magma chamber is believed to be still active and contain at least 15,000 cubic km of melt.
It cannot be ruled out, nor predicted that there will be another super-volcano eruption at Yellowstone in some (geologic) future.
In recent years, the caldera has been studied and is being monitored more closely. In recent years, Yellowstone has been showing unrest in the form of deformation, ground uplift, temperature changes, and seismic swarms, all of which have been followed with great interest and rising some concern. 70 small earthquake swarms were recorded at Yellowstone volcano between 1983 and 2006. On the other hand, such activity is probably entirely normal for a large dormant super-volcano.
Despite the unrest, there is currently no reason to believe that these are precursors to another large super-volcano eruption to happen in the nearer future (years to decades). More likely, these are normal activities in dormant stages of large active volcanic systems. In addition, most of the activity can be related to the hydrothermal system rather than the magma chamber itself.
Statistically, even though the interval of time lapsed since the last such eruption is similar to the intervals separating the past 3 eruptions, statistical likelihood that such an event will repeat itself in the next few 100 years is very low. Unfortunately, most media reports in recent years have been exaggerating this risk greatly.
During the month of December 2012, the University of Utah reports 101 earthquakes were located in the Yellowstone National Park region with a notable increase of earthquake swarms. ...more
The largest earthquake was a magnitude 2.6 event on December 15, 2012, at 6:25 AM MST, located about 10 miles north of Pahaska Teepee, WY. Dec. 9 through Dec. 10 a small swarm of 11 events was located 9 miles north northwest of West Yellowstone, MT with magnitudes 0.3 to 2.1. On Dec. 13 a small swarm of 12 quakes was recorded about 13 miles east of Old Faithful, YNP with magnitudes 0.3 to 2.1. Also on Dec. 13 a small swarm of 12 quakes was recorded between Lewis and Shoshone Lakes with magnitudes 1.4 to 2.5. Overall Yellowstone earthquake rates are normal for this monthly reporting period. Slow subsidence of the caldera, which began in early 2010, continues. Current deformation patterns at Yellowstone are well within historical norms. [less]
Time and depth of quakes at Yellowstone during Oct 2012
Yellowstone earthquake activity remains at background levels. ...more
During October 2012, 128 earthquakes were recorded in the Yellowstone National Park region. The largest were a pair of magnitude 3.1 events on October 14 at 8:55 PM and 9:21 PM MDT, located about 18 miles south southwest of West Yellowstone, MT. These events were part of a swarm of 55 quakes recorded October 14 -16, with magnitudes ranging from M 0.9 to M 3.1. [less]
Current seismic signal b207 station (Univ. Utah / USGS)
A small earthquake swarm occurred under the Yellowstone caldera. The quakes are few and very small and no indicator of an impending eruption. It completely falls under what is normal behavior of an active caldera.
