Glaciers not only melt from the tops exposed to the air, but also some from the bottom, that is, melt into the sea. Since scientists can’t get there precisely, this melting may be difficult to study. But now, researchers are using robotic kayaks to monitor freshwater plumes from beneath glaciers and find that they are melting much faster than we thought.
Alaska’s Le Conte Glacier, known as the Tidal Glacier, is essentially a 20-mile (32-kilometer) glacier that flows into the sea. For the new study, researchers were interested in how and how much ice meets the sea, but because blocks often fall, it’s too dangerous to get close.
As a result, the team instead sent robotic kayaks. They are programmed to cruise around the icy cliffs and measure the “surrounding meltwater invasion”, which means that fresh water from glaciers flows into the ocean. No one has studied this particular type of meltvery very carefully in the past, so only estimates have been made in the model.
Traditionally, these models have shown that melting in this environment is relatively small compared to the daily understanding of melting on the surface of glaciers. But new research has found that the melting of the sea’s environment is much higher than the model had expected, and in fact 100 times higher.
Rebecca Jackson, lead author of the study, said: “With robotic kayaking, we found surprising signs of melting: large amounts of melting water invading the ocean, revealing the critical importance of processes that are often ignored when modeling or estimating melting rates.” “
The new study isn’t the only one that can spy on what’s happening under a glacier at sea level. Last year, a NASA satellite used radar to reveal a huge hole beneath the Thwaites glacier in Antarctica, which had previously contained 14 billion tons of ice. Another study found that melting glacial water alters the chemical properties of surface seawater, further accelerating sea level rise.
The new study, published in Geophysical Research Letters, could help improve our glacier melting models.