Scientists Reveal: South Africa Is Emerging From The Ocean

Scientists Reveal: South Africa Is Emerging From The Ocean

As climate change accelerates, South Africa is not only experiencing increased heat and dryness—it’s also gradually rising by as much as 2 millimeters per year, according to new research.
Image Credits: Pixabay

As climate change accelerates, South Africa is not only experiencing increased heat and dryness—it’s also gradually rising by as much as 2 millimeters per year, according to new research.

While scientists already recognized this upward movement, they previously attributed it to mantle flow beneath the Earth’s crust in the region.

However, the new study links the uplift to recent droughts and the resulting loss of surface water, a pattern associated with global climate change.

Data from a network of global navigation satellite system (GNSS) stations across South Africa made this finding possible. Originally intended for atmospheric studies, the network delivers highly accurate measurements of elevation changes at different locations.

“Between 2012 and 2020, the data showed an average elevation increase of 6 millimeters,” says geodesist Makan Karegar from the University of Bonn.

From Mantle Activity to Water Loss

Previously, scientists attributed the Quathlamba hotspot—a localized swelling of Earth’s crust caused by an upswelling of material from a mantle plume beneath the area—to explain the ongoing uplift.

“But we’ve now tested an alternative explanation,” says Karegar. “We believe that the loss of groundwater and surface water may also be causing the land to rise.”

To investigate this theory, Karegar and his team analyzed GNSS elevation data alongside rainfall patterns and other hydrological indicators throughout South Africa.

A clear correlation emerged: regions that experienced severe droughts in recent years showed the most significant uplift.

The most notable rise occurred during the intense 2015–2019 drought, a time when Cape Town faced the looming threat of “day zero”—the projected day the city would run out of water.

Image Credits: The change in height of different GPS stations (red = rising; blue = sinking). The rise was particularly pronounced between 2015 and 2019. (AG Kusche/University of Bonn)

Satellite Data Offers Broad Insight into Water Loss

The researchers also incorporated data from the GRACE satellite mission—a collaboration between NASA and the German Aerospace Center designed to track Earth’s gravity field and shifts in water distribution.

“These measurements help us determine changes in total water storage, including surface water, soil moisture, and groundwater,” explains Christian Mielke, a geodesist at the University of Bonn. “However, the satellite’s spatial resolution is limited to several hundred kilometers.”

Even with that limitation, the GRACE data backed up the team’s theory: areas with reduced water mass showed greater land uplift at nearby GNSS monitoring stations.

To gain more detailed insights, the researchers turned to hydrological models, which offered higher-resolution analysis of how drought conditions affect the water cycle.

“This data also indicated that the land uplift is largely due to drought and the resulting loss of water mass,” says Mielke.

Mantle Plume and Moisture Loss Drive Uplift

The researchers propose that, alongside the upward force from a mantle plume, the reduction of moisture in the Earth’s crust may also be contributing to the land’s rising.

This finding highlights yet another way climate change is reshaping our planet—but it may also have practical benefits.

GNSS data, which are affordable and easy to gather, could serve as a new tool for monitoring water scarcity, including vital groundwater reserves that are often overdrawn for farming and other human activities.

With droughts posing a serious threat not only in South Africa but globally, this research could offer a valuable method for tracking water availability and managing water resources more effectively.


Read the original article on: Sciencealert

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