The seven-year study, which kicked-off in 1997, was led by Charles Wicks and used satellite pictures snapped by the ERS-2 probe. Their research showed an upswelling of magma under the northern edge of the caldera – near the Norris Geyser Basin – causing subsidence across the park. It means the caldera rim can rise while the floor sinks very closely to each other in time.
The surface appears to be in constant motion, rising and falling, but Dr Wicks said the team needed more time to understand what is happening.
He said in 2007: “We need 10 to 20 years of research before we can get a feel for normal behaviour.
”Then we can predict what’s happening based on the abnormal behaviour.
“We propose that the observed patterns of uplift and subsidence result from the nearly continuous movement of molten basalt into and out of the Yellowstone volcanic system.”
Dr Wicks and his colleagues believe that magma is rising from beneath the Sour Creek Dome, in the caldera’s eastern section, where it hits the solid mantle layer and spreads out.
As magma pulses into the chamber under the dome, the dome swells and rises.
Then, when the magma pulse leaks out through fractures under the north rim of the caldera, the dome settles back.
He added: “As the magma loses heat and cools, it dives back under the Mammoth [Hot Springs].
“Right now, we’re looking at a new episode of uplift that started in 2004.”
Dr Wicks is yet to provide an update on the situation
However, the discovery does not mean the supervolcano is any closer to erupting, despite claims it is overdue.
Researchers working for the USGS have stated this theory couldn’t be further from the truth.
Their website reads: “First of all, one cannot present recurrence intervals based on only two values, it would be statistically meaningless.
“But for those who insist, let’s do the arithmetic – the three eruptions occurred 2.1 million, 1.3 million and 0.64 million years ago.
“The two intervals are thus 0.8 and 0.66 million years, averaging to a 0.73 million-year interval.
“Again, the last eruption was 0.64 million years ago, implying that we are still about 90,000 years away from the time when we might consider calling Yellowstone overdue for another caldera-forming eruption.
“Nevertheless, we cannot discount the possibility of another such eruption occurring sometime in the future, given Yellowstone’s volcanic history and the continued presence of magma beneath the Yellowstone caldera.”
