A big blob of molten rock appears to pushing up remnants of an ancient volcano in Yellowstone National Park in Wyoming, scientists reported Friday.

They say no volcanic explosion is imminent – that already happened 642,000 years ago, creating the volcanic crater known as a caldera where part of Yellowstone Lake sits.

But satellite readings show just how volcanically active the area remains, the researchers reported in the journal Science.

From the middle of 2004 through 2006, the floor of the caldera rose 7 inches at a rate of 2.8 inches a year – the biggest rise ever measured, they reported.

“There is no evidence of an imminent volcanic eruption or hydrothermal explosion. That's the bottom line,” University of Utah seismologist Robert Smith said in a statement. 

Source : Sign on Sandiego
See Also :  Volcanoes: Ready, stead, blow,  Yellowstone's Super Sisters - A List of Known Supervolcanoes,  The Yellowstone Caldera,  Super Volcano at Yellowstone National Park