Unveiling the hidden spark: New insights into earthquake prediction
Researchers have identified the "ignition" mechanism of earthquakes, and their latest findings were published in Nature. They believe that understanding the slow movements of tectonic plates preceding these extreme events could help predict earthquakes.
Scientists have explored the hidden mechanism that explains the "ignition" of earthquakes. Their latest findings are detailed in the scientific journal "Nature." They propose that slow, creeping movement without tremors might be a necessary prelude to shocks. This discovery offers new insights into the fundamental mechanisms of these catastrophic events and opens potential avenues for prediction.
Laboratory experiments unveil the physics of fractures
Research led by physicist Jay Fineberg at the Hebrew University in Jerusalem focused on fractures in sheets of plastic under laboratory conditions. Although these materials differ from the rocks composing the Earth's crust, the experiments help elucidate the basic principles of physics concerning the formation of fractures by transforming friction into a sudden split at the junction of two surfaces.
Earthquakes occur when tectonic plates moving against each other become locked, and stress along the fault increases. Fineberg explains that these plates are subjected to escalating forces but are blocked by a rigid part of the boundary separating them, which eventually breaks. The process doesn't occur immediately—an initial fracture must form, which accelerates upon reaching the brittle zone's limits, resulting in strong ground vibrations.
From slow "creeping" to sudden fracture
The mystery has been how this initially slow process transforms into rapid fracturing. The research team discovered that a so-called nucleation front, an initial fracture, develops slowly in the zone between tectonic plates before the fracture. Although these fronts advance slowly and don't release much energy, they expand over time, and the energy needed for further fracturing increases with the size of the fracture.
Ultimately, additional energy penetrates further when the fracture extends beyond the brittle zone, leading to sudden and violent displacement. Fineberg notes that understanding aseismic movement could make earthquake prediction possible. His team is investigating how such movement transitions into seismic activity in the laboratory, which may aid future forecasts for early earthquake warnings.
The potential for earthquake prediction
Fineberg and his team strive to detect signs of the laboratory transition from aseismic to seismic movement. "So maybe we can uncover what you can’t really do in a real fault, because you have no detailed information on what an earthquake is doing until it explodes," the researcher stated.
These discoveries highlight how slow creeping before a fracture can rapidly lead to an earthquake. Theoretically, if it were possible to measure aseismic movement before a fracture—on a fault or even in a mechanical object like an aeroplane wing—it would be feasible to predict the fracture before it occurs.
The discovery of earthquakes' hidden "ignition" mechanism represents a breakthrough in understanding these catastrophic events. The potential for predicting earthquakes presents new opportunities for safeguarding lives and infrastructure.
