An enormous mass of warm rock is rising slowly but steadily toward the surface of New England and for now, researchers cannot explain this kind of abrupt activity.
“Our study challenges the established notion of how the continents on which we live behave,” Vadim Levin, a geophysicist and professor at Rutgers University-New Brunswick, stated in a press release.
“The upwelling we detected is like a hot air balloon, and we infer that something is rising up through the deeper part of our planet under New England.”
Seismic data shows a rising balloon of warm rock beneath New England. Photo by Vadim Levin/Rutgers University-New Brunswick
“It is not Yellowstone (National Park)-like, but it’s a distant relative in the sense that something relatively small – no more than a couple hundred miles across – is happening.”
The study focused on New England, because scientists had previously documented an area of great warmth (hundreds of degrees Celsius warmer than neighboring areas) in the Earth’s upper mantle. For two years, data was gathered by the National Science Foundation’s EarthScope program and thousands of seismic measurement devices, which were 46.6 miles apart, covered the continental United States.
“We’re interested in what happens at the interface between tectonic plates – thick, solid parts that cover our planet – and material in the upper mantle beneath the plates,” Levin said.
“We want to see how North America is gliding over the deeper parts of our planet. It is a very large and relatively stable region, but we found an irregular pattern with rather abrupt changes in it.”
The observations of seismic activity point to the upwelling pattern detected beneath central Vermont and western New Hampshire, but it’s also under western Massachusetts.
“The Atlantic margin of North America did not experience intense geologic activity for nearly 200 million years,” Levin said. “It is now a so-called ‘passive margin’ – a region where slow loss of heat within the Earth and erosion by wind and water on the surface are the primary change agents.
So we did not expect to find abrupt changes in physical properties beneath this region, and the likely explanation points to a much more dynamic regime underneath this old, geologically quiet area.”
“It will likely take millions of years for the upwelling to get where it’s going,” he added. “The next step is to try to understand how exactly it’s happening.”