Scientists at Washington University in St. Louis, led by seismologist Douglas Vince, have completed one of the first seismic surveys of the Patagonian Andes. In it, they displayed and described the local underground dynamics. Patagonia is a remote and not densely populated region.
Changes in the size of glaciers are leading to rapid and variable uplift of the region.
Hannah Mark, former Earth and Planetary Science Fellow at the University of Washington
Seismic data show that there is a gap in the descending tectonic plate. It caused hot, less viscous mantle material to flow under South America.
Above this gap there are ice fields, their number has begun to decrease. Therefore, the weight that previously caused the continent to sag down was reduced. The scientists found very low seismic activity in and around the rupture, as well as thinning of the rigid lithosphere covering the rupture.
Due to these conditions, many recent changes have occurred in Patagonia, in particular the uplift of the lithospheric plates in certain areas that were once covered with ice.
When the glaciers melt, the pressure on the Earth is reduced: a huge amount of water flows into the oceans. As a result, lithospheric plates begin to actively rise.