Researchers discovered that the 2023 Morocco earthquake was caused by movement deep below the Earth’s surface. In September 2023, the High Atlas Mountains in western Morocco experienced a magnitude 6.8 earthquake. This event, which caused widespread damage and loss of life in rural areas, may have been triggered by mantle upwelling.
On September 8, 2023, the earthquake struck western Morocco, resulting in significant destruction and numerous fatalities in the High Atlas Mountains. The previous major earthquake in Morocco occurred in 1960, leading to a long period of seismic inactivity that left the region underprepared for such a disaster.
Typically, most seismic activity in Morocco occurs near the Rif Mountains in the north, where the African and Eurasian plates converge. However, near the High Atlas Mountains, the plates converge at a much slower rate of about 1 millimeter per year. It’s believed that mantle upwelling beneath the High Atlas significantly contributes to the height of these mountains, which rise over 4,000 meters.
By analyzing geodetic and seismic data, Huang et al. determined that the 2023 earthquake originated in the Tizi n’Test fault system, with a fault plane about 26 kilometers below the surface. The strongest effects of the rupture occurred at depths of 12-36 kilometers, causing displacement of the Moho, the boundary between the crust and the mantle at around 32 kilometers deep.
Due to the earthquake’s unusual depth and its distance from plate boundaries, researchers suggest that mantle upwelling, rather than surface faulting activity, triggered the quake. The findings indicate that seismic hazard models should include more data on deeper dynamics in intraplate regions, which are often overlooked in favor of plate boundary dynamics. This highlights the need for enhanced seismic monitoring in regions with slow deformation rates and complex fault structures, which can lead to infrequent but devastating earthquakes.
