Today’s event is the largest earthquake at Yellowstone since February 22, 1980, and occurred near the center of a region of recent ground uplift described in a YVO Information Statement on February 18, 2014. The Yellowstone Volcano Observatory has been tracking this uplift episode for about 7 months.
As discussed in the March 3, 2014 YVO Monthly Update, seismicity in the general region of the uplift has been elevated for several months. A previous period of uplift in this area occurred between 1996 and 2003, and it was also accompanied by elevated seismicity.
A USGS field team is in Yellowstone and will visit the area near the earthquake’s epicenter today. The team will look for any surface changes that the earthquake may have caused, and for possible effects to the hydrothermal system at Norris Geyser Basin.
Based on the style and location of today’s earthquake, at this time YVO sees no indication of additional geologic activity other than continuing seismicity.
And speaking of potential SHTF disasters:
The loosely defined term ‘supervolcano‘ has been used to describe volcanic fields that produce exceptionally large volcanic eruptions. Thus defined, the Yellowstone Supervolcano is the volcanic field which produced the latest three supereruptions from the Yellowstone hotspot; it also produced one additional smaller eruption, thereby creating West Thumb Lake 174,000 years ago. The three super eruptions occurred 2.1 million, 1.3 million, and 640,000 years ago, forming the Island Park Caldera, the Henry’s Fork Caldera, and Yellowstone calderas, respectively. The Island Park Caldera supereruption (2.1 million years ago), which produced the Huckleberry Ridge Tuff, was the largest and produced 2,500 times as much ash as the 1980 Mount St. Helens eruption. The next biggest supereruption formed the Yellowstone Caldera (640,000 years ago) and produced the Lava Creek Tuff. The Henry’s Fork Caldera (1.2 million years ago) produced the smaller Mesa Falls Tuff but is the only caldera from the Snake River Plain-Yellowstone (SRP-Y) hotspot that is plainly visible today.
We may be about due for another super eruption, if the decreasing time between such eruptions – 800,000 years, 700,000 years – continues. The last such eruption occurred 640,000 years ago, so we may even be overdue.