The discovery of the new mechanism is important for creating accurate models about rising sea level.
For the first time, the investigators recorded numerous “ice earthquakes” in the depths of Granelândia’s ice cloak, revealing a previously unknown mechanism which influences the way their frozen rivers move toward the ocean.
The discovery, in Science magazine, could alter the way scientists shape the movement of ice and predict Future Sea Level Climb.
A team of investigators made the discovery by inserting a fiber optic cable in a 2.7 kilometers In the northeastern ice stream of Grolândia – the largest of its genre, responsible for draining huge amounts of ice from the ice cloak to the North Atlantic. Like the earthquakes, the earthquakes occur when the ice fractures and moves along failed structures, generating seismic waves, explains the.
So far, these ice seasters had not been detected because their seismic signs were blocked by a buried layer of volcanic particles located about 900 meters below the surface. These particles originated in the old eruption of Mount Mazama, Oregon, about 7700 years ago.
These particles not only prevent seismic waves from reaching the surface, but they can also be responsible for the earthquakes themselves. The main researcher, Andreas Fichtner, from ETH Zurich, explained that impurities such as sulfates and other volcanic waste can destabilize the ice, causing the formation of cracks and triggering small localized tremors. These tremors propagate themselves as a chain reaction, spreading through vast areas of the ice stream.
“We were surprised by this previously unknown relationship Between the dynamics of an ice stream and volcanic eruptions, ”said Fichtner.
Scientists have long been struggling to model the movement of ice currents, which play a key role in Ice cloak drainage from Gronelândia and contribute to the rising of sea level. Until recently, it came from the principle that these frozen rivers ran constantly, such as a thick honey.
However, this new study, along with previous investigations, calls into question this assumption. The detection of ice tremors suggests that ice chains also move irregularlysimilar to the way tectonic plates move before an earthquake.
This revelation has important implications for climate change models. Granelândia’s ice cloak, which covers 80% of the island, has already contributed to a increase of about 1 centimeter At the global level of the sea since the 1990s. If it melted completely, it could increase the sea level by an impressive 7 meters.
