- Current Update, last updated May 1, 2014 12:50 :
The ground deformation occurring in north-central Yellowstone abruptly changed direction on about April 6, 2014, one week following a M4.8 earthquake in the same region. The change is most prominent on the NRWY GPS station (http://earthquake.usgs.gov/monitoring/gps/YellowstoneContin/nrwy/), but is also detectable on other nearby stations. Since April 6, 2014, NRWY has moved about 0.5 cm west, 1 cm north, and 2 cm down, reversing about 1/3 of the deformation accumulated over the previous 8 months. (Note that last month’s update erroneously reported that NRWY had moved 2 cm north since August 1, 2013. In fact it had moved 2 cm SOUTH).
Slow caldera uplift, which began in early 2014 after 4 years of subsidence, continues at about 2 cm/yr.
During April 2014, the University of Utah Seismograph Stations reports 182 earthquakes were located in the Yellowstone National Park region. The largest event was a small earthquake of magnitude 3.1 on March 31, at 10:32 PM MDT (April 1, at 04:32 UTC), located about three miles north-northeast of Norris Geyser Basin in Yellowstone National Park, Wyoming.
April 2014 seismicity was characterized by the continuation of the late-March seismicity, including the largest earthquake to occur in Yellowstone in the past 34 years. The sequence of earthquakes, from March 27 through April, consisted of 144 earthquakes ranging in magnitudes from -0.05 to 4.8. The sequence included one magnitude 4 event, six magnitude 3 events, 33 magnitude 2 events, and 104 events less than magnitude 2, encompassing three earthquake clusters in the Norris Geyser Basin region. One new unrelated earthquake cluster occurred near Old Faithful, WY. The April earthquake sequences are described below.
1) A north-south trending series of earthquakes, over seven miles in length, which began in September, 2013 decreased in intensity through April 27 with only 68 total events. The majority of seismicity occurred before April 12 and the largest earthquake (magnitude 2.8) occurred on April 5, at 07:19 PM MDT, located 17 miles east-notheast from West Yellowstone, MT.
2) The earthquake series containing the March 30 magnitude 4.8 event began on March 27 and continued into April, with an additional 31 earthquakes in April, including the month's largest earthquake (M3.1) noted above.
3) A smaller series of 11 earthquakes occurred over five hours on April 7. The largest earthquake in the series (magnitude 1.5) occurred on April 7, 00:01 AM MDT, located about 12 miles south of Mammoth, WY.
4) A small series of 14 earthquakes began April 11. The largest earthquake in the series (magnitude 2.1) occurred on April, 20, at 03:54 AM MDT, located 4 miles south-southwest from Old Faithful, WY.
Earthquake sequences like these are common and account for roughly 50% of the total seismicity in the Yellowstone region.
The University of Utah Seismograph Stations calculated a moment tensor solution for the March 30 magnitude 4.8 event indicating a dominantly strike-slip, 98% double-couple mechanism, with north-northwest and west-southwest striking nodal planes.
Earthquake activity at Yellowstone is currently at background levels.
- Volcanic History Overview: The Yellowstone Plateau volcanic field developed through three volcanic cycles spanning two million years that included some of the world's largest known eruptions. Eruption of the >2450 cu km Huckleberry Ridge Tuff about 2.1 million years ago created the more than 75-km-long Island Park caldera. The second cycle concluded with the eruption of the Mesa Falls Tuff around 1.3 million years ago, forming the 16-km-wide Henrys Fork caldera at the western end of the first caldera. Activity subsequently shifted to the present Yellowstone Plateau and culminated 640,000 years ago with the eruption of the >1000 cu km Lava Creek Tuff and the formation of the present 45 x 85 km caldera. Resurgent doming subsequently occurred at both the NE and SW sides of the caldera and voluminous (1000 cu km) intracaldera rhyolitic lava flows were erupted between 150,000 and 70,000 years ago. No magmatic eruptions have occurred since the late Pleistocene, but large phreatic eruptions took place near Yellowstone Lake during the Holocene. Yellowstone is presently the site of one of the world's largest hydrothermal systems including Earth's largest concentration of geysers.
- Location: Western US, WY
Elevation: 2805 m
- Hazard Assessments: Christiansen, R. L., Lowenstern, J. B., Smith, R. B., Heasler, H, Morgan, L. A., Nathenson, M., Mastin, L. G., Muffler, L. J. P., and Robinson, J. E., 2007, Preliminary Assessment of Volcanic and Hydrothermal Hazards in Yellowstone National Park and Vicinity, U.S. Geological Survey Open-File Report 2007-1071.
- Link to monitoring data:
Recent earthquake activity in Yellowstone National Park (map and catalog with links)
GPS Measured Horizontal Ground Motions
Provisional real-time stream-flow data
See the Yellowstone Volcano Observatory Monitoring Page for more.
Volcanic Alert Level: NORMAL Aviation Color Code: GREEN