Earthquake in Yellowstone
The Hazards and Ramifications
In the United States of America, Yellowstone is considered one of the most active areas as far as seismic activities are concerned. Each year, it receives an approximate of 1000 to 3000 earthquakes even though most of it is not felt. The earthquakes result from large number of faults that are associated with volcano. In 2014, an M4.8 earthquake hit north east side of Norris Geyser Basin, thereby being felt in Yellowstone National Park, towns of Gardiner and West Yellowstone, Montana and all around the area. Since the 1980s earthquake, this is the biggest earthquake at Yellowstone and was part of GPS-determined uplift episode that had built up about four months before the earthquake.
There are many hazards caused by the earthquakes, though the earthquake itself is a hazardous effect of the volcanic eruptions. There could be slipping of rocks, liquefaction, mudslides and landslides in regions that have been hit by the earthquake. Walls, buildings, bridges and other valuable structures in these earthquake-prone areas could also be brought down as a result of severe earthquake multitudes in such areas.These types ofhazards have been experienced in Yellowstone. The 1959 earthquake that hit Red Canyon and Hebgen Lake, producing 22 feet fault scarps. This caused the death of 28 people, with 19 of them having been buried permanently beneath the Madison Canyon landslide. This is because the intense shaking triggered landslide above the Rock Creek campground, making rocks and landslides to tumble into most areas along the highways of Yellowstone national park. The park’s west entrance at West Yellowstone was closed after the roads between Old Faithful and Mammoth were blocked as a result of the earthquake.The historic Old Faithful inn had its indoor chimney collapse into the dining room,and numerous other buildings situated throughout the park were also extensively damaged.
A frequent series of earthquakes within a local area over a short period, commonly dubbed ‘Earthquake swarms’ are a collective experience in Yellowstone, 1985 recording the biggest swarm, recording well over 3000 earthquakes in 3 months. In 2009 and 2010, the swarm was experienced close to both Lake Village and the Old Faithful areas respectively, and numerous earthquakes got recorded. According to scientists, as the hydrothermal fluids migrate, it releases a lot of pressure to the earth’s crust, and it is due to the changing and shifting of these pressures that result into the swarms. Despite the feared effects of earthquakes, they have played a significant role in studying, mapping and even understanding the geology beneath and around the earth surface in Yellowstone. Through studying of the seismic waves, geologists can create images of both caldera and the magma chambers since they can view below the surface and read earthquake-emitted seismic waves. The analysis of the 2014 Yellowstone earthquake showed that the series of earthquake swarms was originated from tectonic forces beneath the ground in the area.
Earthquakes and volcanic eruptions
Earthquakes can trigger volcanic eruptions though that is still a topic of debate by scientists. A volcano can be brought closer to an eruption if the displacement of the earthquake closer to the volcano changes stress around the magma chamber. There have been a series of smaller volcanic eruptions in Yellowstone after the last major eruption that took place 640 years ago. Theses eruptions are believed to be catalyzed by the continuous earthquakes in the region, and they emit rhyolite lava filling a large part of Yellowstone’s caldera. Yellowstone has a of history being one of the largest hydrothermal explosive regions, for instance a large hydrothermal explosion was experienced about 16000 years ago, measuring over 100 meters in diameter. This could have been affected by the earthquakes that hit the area frequently enough.
Husen, S., et al. “Changes in geyser eruption behavior and remotely triggered seismicity in Yellowstone National Park produced by the 2002 M 7.9 Denali fault earthquake, Alaska.” Geology 32.6, 2004). 537-540.
Pitt, A. M., and R. A. Hutchinson. “Hydrothermal changes related to earthquake activity at mud volcano, Yellowstone National Park, Wyoming.” Journal of Geophysical Research: Solid Earth87. B4, 1982. 2762-2766.
Smith, R. B., et al. “Yellowstone hot spot: Contemporary tectonics and crustal properties from earthquake and aeromagnetic data.” Journal of Geophysical Research 82.26, 1977. 3665-3676.