Geologists at Rutgers University and Yale University have discovered a large subterranean mass of hot rock slowly bubbling its way to the surface in the American state of Vermont. Although its discovery is recent, this phenomenon has been ongoing beneath the mountains and forests of New England for tens of millions of years. In a region known for its relative volcanic inactivity, the movement of molten rock beneath the soon-to-be-frozen ground has come as a surprise. “Our study challenges the established notion of how the continents on which we live behave,” said Vadim Levin, Rutgers professor and lead author of the study. “It challenges the textbook concepts taught in introductory geology classes.”
The study used data from the National Science Foundation’s Earthscope program to analyze seismic wave activity to determine the shape, state, and texture of geological objects. Earthscope gathered its data over the course of two years, during which thousands of seismic measurement devices were placed throughout the continental United States, each 46.6 miles apart from the next. Prior to the Rutgers study, scientists had observed that the temperature of New England’s upper mantle is significantly warmer than surrounding regions. This led the Rutgers researchers to focus their attention on Vermont, where the mass of hot rock was discovered.
The recent study’s conclusion offers an alternative perspective on the geological history and future of New England. “The Atlantic margin of North America did not experience intense geologic activity for nearly 200 million years,” said Levin. “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.” Still, no one should expect an eruption in New England any time soon. “It will likely take millions of years for the upwelling to get where it’s going,” said Levin. “The next step is to try to understand how exactly it’s happening.”