MAMMOTH, Wyo. – Yellowstone National Park’s oldest and hottest geothermal area, a favorite spot for park visitors, was shaken by a moderate earthquake Tuesday evening.
The U.S. Geological Survey (USGS) reported a magnitude 3.7 earthquake near Mammoth, Wyoming, at about 6 p.m. MST, close to the Norris Geyser Basin. Seismologists said a few people in the Yellowstone region reported the shaking.
“The earthquake is typical of the Yellowstone region and not a sign of any significant unrest,” the agency said following the quake.
The National Park Service (NPS) said Norris Geyser Basin is home to some truly extreme geothermal features.
The highest temperature ever recorded in Yellowstone (459 degrees) was measured in a drill hole at Norris, just 1,087 feet below the surface, underscoring the intense heat and activity in the area, the NPS added. There are very few thermal features at Norris under the boiling point at 199 degrees at this elevation.
Norris shows evidence of having had thermal features for at least 115,000 years, according to the NPS. The features in the basin change daily, with frequent disturbances from seismic activity and water fluctuations.
The area was named after Philetus W. Norris, the second superintendent of Yellowstone, who provided the first detailed information about the thermal features.
While Yellowstone is frequently rattled by small earthquakes — averaging 1,500 to 2,500 per year — the Yellowstone Volcano Observatory notes that larger, damaging earthquakes have also struck the area.
The park’s largest recorded earthquake, a magnitude 6, occurred on June 30, 1975, along the north-central boundary of Yellowstone Caldera, a few miles southeast of Norris Geyser Basin. No injuries were reported, and all park campgrounds and facilities remained open.