Climate change|The Antarctic seems to rise in some places even by a centimeter a year.
Antarctica gradually lightens as its huge ice mass melts. With the lightening, the continent will rise in the same way as the land has risen, for example, in Finland’s Merenkurku after the ice age.
According to a recent study, the Antarctic bedrock can rise surprisingly quickly.
“Uplift due to ice loss may occur in the coming decades rather than thousands of years,” says in the announcement geophysicist Terry Wilsonone of the authors of the study.
According to some GPS observations, the bedrock of Antarctica is rising up to five centimeters a year in some places. However, the entire Antarctic continent is not rising at the same rate, it is a relatively small area.
A study conducted at the Canadian McGill University was published Science Advances – in science magazine at the beginning of August.
The continent itself in addition, the sea level will rise as the climate warms and the glaciers melt. The continent’s share of sea level rise varies, a recent study says.
The rise of the Antarctic bedrock may mean that the rise of the sea due to the melting of its glaciers would be up to 40 percent more moderate than estimated.
But it can also be the other way around.
The mechanism is complex. At the edges of Antarctica, some of the glaciers extend into the sea below the surface. These glaciers are estimated to be prone to melting, or so-called retreat.
Edge glaciers will melt more slowly if warming can be curbed. Then the continent rises less, which in turn pushes less seawater away from near Antarctica to other sea areas.
If emissions and warming are not curbed, more ice will disappear and the continent will rise more strongly. Then it pushes water away from near Antarctica, causing sea level rise elsewhere to accelerate.
Researchers the modeling is based on GPS data and seismic surveys of the Earth’s mantle under the Antarctic ice mass.
In places the soil is “watery” (squishy). It is precisely in these areas that the earth’s crust can rise unexpectedly quickly.
Of course, there are uncertainties in the modeling, the researchers remind. One reason is the lack of comprehensive seismic measurements, especially in western Antarctica.
Provided of glaciers retreat would be slowed down, so the Antarctic could slow down sea level rise more than predicted.
“If the glaciers continue to retreat in the current or accelerating pattern, the shape of the Antarctic sea and the subglacial bedrock is such that more water can be released into the oceans than previously predicted,” says the research manager in his email. Jyri Näränen From the Geospatial Information Center of the Land Surveying Institute.
A large part of Antarctica has so far not started to react significantly to the current mass change of glaciers caused by climate change. The biggest glaciers react slowly to climate change, says Näränen.
“But if and when the warming continues, they will start to react. Then such models are invaluable to tell you how.”
The globe is not a perfect ball. That is why in some areas the sea rises more than average and in others less. Elevation is affected by, for example, the rotation of the Earth and variations in gravity.
A glacier has a mass whose gravitational force pulls the surrounding sea. The sea surface obeys the gravity field. That is why, for example, the sea level around Antarctica and Greenland is rising.
Nearly 700 million people live on the Earth’s coasts, reminds the glacier researcher Natalya Gomez McGill University in the bulletin. He was the first author of the recent study.
Although, according to him, the rising of the sea cannot be completely prevented, a rapid reduction of emissions could prevent the destruction caused by the melting of the Antarctic glaciers on the coasts.
Read more: What will happen if a giant glacier in Antarctica collapses? A cavity of tens of kilometers has appeared under the Thwaites glacier