Scientists reveal cause behind rising continents
Scientists from the University of Southampton have uncovered the reason behind the mysterious rising of continents. Their research indicates that when continents split apart, the continental crust stretches, causing stirring movements in Earth's mantle. This process triggers powerful waves deep within the Earth, leading to a rise in continental surfaces, sometimes by over a kilometer.
Study sheds light on formation of topographical features
The research team has been studying plate tectonics to understand the formation of topographical features known as "escarpments" and "plateaus." Their findings, published in the journal Nature, are based on the study of global tectonic forces' impact on landscape evolution over hundreds of millions of years. Tom Gernon, Professor of Earth Science at the University of Southampton and lead author of the study, stated that scientists have long suspected these features form when continents rift and split apart.
International collaboration unravels continental movements
The research team, including Dr. Thea Hincks, Dr. Derek Keir, and Alice Cunningham from the University of Southampton, collaborated with colleagues from the Helmholtz Centre Potsdam—GFZ German Research Centre for Geosciences and the University of Birmingham. Their goal was to understand why stable parts of continents sometimes move vertically. Professor Sascha Brune from GFZ Potsdam compared this process to a sweeping motion that disturbs the deep foundations of continents.
Simulations link mantle waves to continental rise
Professor Brune and Dr. Anne Glerum ran simulations that revealed the speed of mantle "waves" moving under continents closely matched major erosion events in Southern Africa following Gondwana's breakup. They concluded that a rifting event sets in motion a "deep mantle wave" that travels along the continent's base at about 15-20km per million years. Brune explained that as continents lose material, they rise, a process similar to a hot-air balloon ascending when it sheds weight. This is known as isostasy.
How continental breakup triggers mantle movements
Building on their previous study linking diamond eruptions to continental breakup, published in Nature last year, the research team used advanced computer models and statistical methods to examine how Earth's surface has responded to the breakup of continental plates over time. They discovered that when continents split, the stretching of the continental crust triggers stirring movements in Earth's mantle, the thick layer between the crust and the core, which influences the surface dynamics and contributes to geological changes.
