Heat that has been escaping from the Earth's core could be making Greenland's ice sheet melt and flow faster, according to new research from a team of geoscientists from around the world, including at Trinity College Dublin.
The discovery means that predictions about the rate of climate change that are based on the movement of ice must also factor in that some of the influence that may be coming from deep under the frozen landscape.
The researchers, including Geology Research Fellow at TCD Dr Alan Vaughan, used a combination of computer models, seismology, gravity measurements, ice-core samples and radar, as well as airborne, satellite and ground based measurements to work out the flow dynamics and subglacial hydrology.
The study says that the unusually hot area of the Earth's core, or mantle, which produces volcanic activity in Iceland, has over millions of year also thinned the depth of ice in Greenland.
As a result there is now a zone 1,200km long and 400km wide where the heat coming from inside the Earth is higher than average, the scientists conclude.
This has caused more water than normal under the ice sheet to melt, which in turn has caused an increase in the speed of the ice's flow, they say.
In particular, the researchers suggest that half of the area of central-northern Greenland that is covered in ice is melting from below.
This in turn is creating a quickly moving flow of ice of up to 750km in length from its peak down to the North Atlantic Ocean.
The findings confirm readings from radar and ice core drilling data, which suggest rapid melting in the area.
"This study demonstrates an unexpected link between hotspot history and ice sheet behaviour," said Dr Vaughan.
"It shows that the influences on ice sheets span a huge range of timescales from the month by month changes of the ice cover to the multi-million year epochs over which the Earth's mantle and tectonic plates evolve."
The study was published in the journal Nature Geoscience.