Unlike traditional land elevation changes typically attributed to tectonic shifts, scientists have discovered that this African nation is rising due to an entirely different cause: severe drought conditions.
This unusual geological behavior offers new insights into Earth’s dynamic processes and potential methods for monitoring water resources.
The rising phenomenon in South Africa Scientists from the University of Bonn have documented a surprising trend across South Africa – the land is steadily rising above sea level.
Much like how massive icebergs can dramatically impact geological conditions, drought appears capable of reshaping landscapes in unexpected ways.
By monitoring land elevation through existing GPS networks, scientists can now infer the status of underground water supplies with remarkable accuracy.
South Africa’s gradual but notable upward movement is a remarkable geological phenomenon. Scientists have found that this African country is rising for a completely different reason: extreme drought conditions, as opposed to the conventional land elevation changes that are usually ascribed to tectonic shifts. New understandings of Earth’s dynamic processes and possible techniques for water resource monitoring are provided by this peculiar geological behavior.
a growing trend in South Africa.
A startling trend has been observed throughout South Africa by scientists from the University of Bonn: the land is gradually rising above sea level. According to their findings, which were published in the Journal of Geophysical Research: Solid Earth, some areas are rising up to two millimeters per year. Even though it might not seem like much, this movement indicates a lot of activity over geological timescales.
An average elevation increase of 6 millimeters was recorded by South Africa’s vast network of permanent GPS stations across several regions between 2012 and 2020. The most significant changes occurred in the Western Cape province, where elevation gains of 5–6 millimeters occurred exactly during the severe drought that lasted from 2015–2019. Pretoria and northern KwaZulu-Natal showed similar trends, albeit at slower rates of two to three millimeters.
This elevation pattern directly correlates with the severity of the drought, which contradicts conventional wisdom regarding land movement. Similar to the profound effects that enormous icebergs can have on geological conditions, drought seems to have the power to drastically alter landscapes.
The unanticipated driver was drought.
The phenomenon can be explained mechanically, according to the research team’s analysis. Due to the significant weight of water, the land below is compressed when soil and subterranean aquifers get saturated. The earth’s crust can rise a little as drought conditions worsen and water evaporates or is consumed; this is comparable to a compressed foam ball expanding when pressure is released.
In order to verify their theory, scientists integrated data from the GRACE satellite mission, which monitors changes in Earth’s gravitational field, with GPS readings. Although the satellites only had a few hundred kilometers of spatial resolution, the results were clear: regions that lost water mass had correspondingly higher land elevations.
The analysis was improved by the addition of high-resolution data from local hydrological models. There is a distinct pattern in the relationship between elevation change and water quantity: areas with water saturation exhibit little elevation change (0-0point 5 mm annually), whereas areas affected by drought see more notable increases (approximately 2 mm annually).
keeping an eye on consequences and potential uses.
An inventive approach to monitoring groundwater supplies is provided by this discovery. Scientists are now able to determine the condition of subterranean water supplies with remarkable accuracy by using existing GPS networks to monitor land elevation. This method provides a simple, affordable way to predict water emergencies and guide decisions about water restrictions.
Authorities may have been able to lessen the severity of the situation if such monitoring had been in place during Cape Town’s 2018 water crisis, when the city almost ran out of drinking water. In arid regions like the Sahel, California, and the Mediterranean basin, this monitoring strategy may prove invaluable as climate models predict more frequent and severe drought periods globally.
The ramifications go beyond water management. Other areas that are suffering from significant climate impacts might see comparable geological reactions. Scientists monitor the effects of enormous cosmic events on Earth, but these changes on the ground serve as a reminder that Earth’s systems are still dynamic and sensitive to their surroundings.
