According to a US Geological Survey report, the Earth is still rumbling under Yellowstone National Park. In July 2021, there were more than 1,000 earthquakes in the area. According to the report, this is the highest level of seismic activity that the park has witnessed in a single month since June 2017 when more than 1,100 earthquakes rattled the region.These earthquakes were not very strong, with four of them measuring in the magnitude-3 region (strong enough to feel but unlikely to cause any damages). Park seismologists also said that none of these quakes indicated that the supervolcano beneath the park was likely to blow.According to the USGS report, "While this level of seismicity may be above average, it is not unusual and does not reflect magmatic activities." We would expect other indicators such as changes in deformation or thermal/gas emission to indicate magmatic activity. However, no such variations were found.Related: Rainbow Basin Photos of Yellowstone's grand prismatic hot springThe University of Utah Seismograph Stations recorded 1,008 earthquakes throughout July 2021. They are responsible for monitoring the Yellowstone Park region and analysing them. These earthquakes occurred in seven swarms with the most powerful occurring on July 16.According to the USGS there were at least 764 earthquakes that struck the ground below Yellowstone Lake on that day. One of them was a magnitude-3.6 earthquake, which was the largest in the month.According to the report, six of the remaining swarms for this month were smaller than expected, with between 12 and 40 earthquakes per swarm, each measuring below magnitude 3.The USGS said that these quakes should not be considered alarming. They also noted that the earthquakes are likely to result from motion on existing faults beneath the park. The melting of snow can stimulate fault movements, increasing groundwater seepage under the park and raising pressure underground.Yellowstone is one the most seismically active areas in the US. According to the National Park Service, the area is often hit by 700-3,000 earthquakes per year. Most of these are not visible to visitors. In 1959, the largest quake in Yellowstone was the magnitude-7.3 Hebgen lake quake.Why is the park so fragile? The park is situated on top of a network fault lines that are associated with an immense volcano deep below the ground. According to the USGS, this volcano last erupted around 70,000 years ago.Earthquakes are caused by the fault lines that run through the region and the movement of magma, water, and gas beneath the surface. These features feed the park's hot springs and geysers.Yellowstone's volcano has erupted many times before, with massive eruptions about every 725,000 years. This schedule indicates that the park will experience another major eruption within approximately 100,000 years.Live Science previously reported that such an eruption could devastate the whole United States. It would clog rivers across the continent with ash and cause widespread drought and food insecurity.Similar content:Yellowstone National Park: The Early Years (photos).Photo: The best national parks to visit in winterYellowstone's grizzly bear trapping photographsLive Science originally published this article. You can read the original article here.