15-06-2025
Satellite data shows South Africa rising 6mm: Here's why it matters
South Africa's landmass is slowly rising, and new research suggests the surprising cause may not be deep within the Earth but rather due to repeated droughts and water loss.
A study from the University of Bonn, Germany, analysing over two decades of satellite data has found that the country experienced a vertical uplift of around 6 millimetres between 2012 and 2020.
Scientists say this change is linked to the loss of surface water, with the land rising in response to the weight being lifted.
The study used data from the Global Navigation Satellite System (GNSS) base stations across the country to track vertical land movement. Researchers originally considered that this might be due to geological forces such as mantle flow and dynamic topography, the slow, deep movements in the Earth's crust and mantle. However, they now say the evidence points to a different explanation.
"Our evidence suggests that land water loss from multiple droughts is a major driver of the observed uplift," the researchers wrote.
To reach this conclusion, the team analysed daily height records from Global Positioning System (GPS) stations between 2000 and 2021. They applied a method known as Singular Spectral Analysis (SSA) to separate long-term trends and seasonal variations from random noise in the data.
