As small earthquakes continue to rumble around the Yellowstone supervolcano in Wyoming, scientists have revealed new evidence of the changes going on beneath the ground.
A new map from the US Geological Survey shows how the ground around the Yellowstone caldera has deformed over the span of two years, as the quakes release uplift-causing pressure, allowing the ground to sink back down.
This activity is typically linked to changes in magma and gases deep below the surface – but for now, the experts say there’s no cause for worry.
Scroll down for video
The University of Utah’s Seismograph Stations (UUSS) have been monitoring the activity since it began June 12.
A total of 1,562 quakes have been recorded so far at Yellowstone since the swarm began.
Earthquake swarms are common in Yellowstone and, on average, comprise about 50 per cent of the total activity in the Yellowstone region.
Although the latest swarm is the largest since 2012, it is fewer than weekly counts during similar events in 2002, 2004, 2008 and 2010.
Tremors were recorded from ground level to 9mi (14.5km) below sea level.
Seismic activity could be a sign of an impending eruption of the supervolcano, although this is impossible to predict exactly
The map, created by USGS geophysicist Chuck Wicks uses data from June 2015 and July 2017 to show how the region around Yellowstone has changed.
In the map, the colourful rings show the changes in the ground’s elevation as seen by a radar satellite, according to USGS.
A bulls-eye shaped section of uplift can be seen at the Norris Geyser Basin, where the ground has risen roughly 3 inches.
And, an elliptical subsidence can be seen in the Yellowstone caldera, with the ground dropping about 1.2 inches.