West Antarctica is one the fastest-warming areas on Earth. Thwaites Glacier, also known as "Doomsday Glacier", is a good example.
Thwaites has lost 595 billion tonnes (540 billion metric tonnes) of ice since the 1980s. This contributes 4% to global sea-level rise annually, Live Science previously reported. In the last three decades, the glacier has seen its rate of ice loss accelerate substantially. This is partly due to hidden rivers containing comparatively warm seawater that cut across the glacier's bottom and unmitigated climate change which has warmed the ocean.
New research has shown that Thwaites is not being driven by the warming atmosphere and ocean. The heat from the Earth may be causing Thwaites' glaciers to scream.
Related: Wild satellite image shows close collision of A-74 icebergs in Antarctica
Researchers used geomagnetic field data taken from West Antarctica to generate new maps of geothermal heat flows in the region. These maps are basically maps that show how much heat is being emitted from the Earth's interior to heat the South Pole.
Researchers found that the crust under West Antarctica is much thinner than East Antarctica, approximately 10 to 15 miles (17-25 kilometers) thicker in the West than it is in the East. This exposes Thwaites Glacier more to geothermal heat then glaciers on the opposite side of the continent.
"Our measurements showed that geothermal heat flow can occur below Thwaites Glacier where the Earth's crust has only 17-25 kilometers thick," Ricarda Dziadek (lead study author), a geophysicist at Alfred Wegener Institute (AWI), Helmholtz Centre for Polar and Marine Research, Germany said in a statement.
Related: Dramatic images capture the rapid slide of Antarctic glacier
The crust under the seabed of West Antarctica is thinner than that below East Antarctica because it lies in an oceanic trench. Scientists suspect that the crust beneath the oceanic trench is absorbing more heat from the planet’s upper mantle, which has an average temperature of 392 degrees Fahrenheit (or 200 degrees Celsius). This could have an impact on the formation and evolution glaciers over many millions of years.
The researchers measured the difference in heat flow in the new study. The team used a variety magnetic field datasets to calculate the distance between crust and mantle at different spots in Antarctica. They also calculated the relative heat flow within those areas.
It is difficult to determine the exact temperature of the glacier where it meets the seabed. Different types of rock conduct heat differently so it's difficult to know. However, researchers stated that it is clear that Thwaites will be disappointed by this additional heat source in the West.
According to Karsten Gohl (also a geologist at AWI), "large amounts of geothermal warmth can, for instance, cause the bottom of the glacier to stop freezing completely or to a continuous film of water forming on it's surface." Gohl said that either of these conditions could lead to glacier's ground ice sliding more easily, which would cause glacier's loss to "accelerate significantly".
This scenario could prove to be a test for the Doomsday Glacier's reputation. If Thwaites Glacier collapses completely into the ocean, global sea level would rise by approximately 25 inches (65 cm) and cause severe damage to coastline communities all over the globe, Live Science previously reported. The glacier is not required to block the West Antarctic Ice Sheet's edge, which could lead to sea level rise at unprecedented rates.
Researchers will soon be able to improve their understanding of heat flow below Antarctica. At the South Pole, a major international research project is underway. This includes missions to drill cores of ice that extend down to Thwaites Glacier's bed. These core samples may provide scientists with heat flow measurements that could help them determine how long the Doomsday Glacier is still ticking.
Original publication on Live Science
