CanadaThe area off the coast of Vancouver Island experienced nearly 2.000 earthquakes in a single day as seismic activity revealed the impending creation of new ocean crust.
Vancouver Island seen from above. Image: WordPress
Nearly 2.000 earthquakes shook a location off the coast of Canada in one day in early March 3, possibly a signal that new ocean crust is about to be born through magmatic faulting, Live Science reported on March 21. Earthquakes do not threaten humans. They are relatively small and concentrated in a spot called Endeavor Beach, about 3 km off the coast of Vancouver Island. The site contains several hydrothermal veins and is located on the Juan de Fuca Ridge, where the ocean floor is separating.
According to Zoe Krauss, a doctoral student in marine geophysics at the University of Washington, the above area is separate from the subduction zone, where one tectonic plate sinks into the mantle below another tectonic plate, closer to shore. and can create large, destructive earthquakes. “Mid-ocean ridges cannot produce large earthquakes, the intensity is no higher than 5 magnitude. This will not trigger large earthquakes on the subduction zone,” Krauss said.
Earthquakes are scientifically interesting because they can reveal details about the process by which the ocean floor separates and new crust forms. At Endeavor Bank, the Pacific Plate and the Juan de Fuca Plate are moving away from each other. That stretching creates long, straight fault lines and thins the crust, allowing magma to rise. When magma reaches the ground, it cools and hardens, forming new ocean crust.
Endeavor Bank is continuously monitored as part of the Northeast Pacific Time-Series Subsea Network Experiment (NEPTUNE) program operated by the Ocean Networks Canada initiative. Since 2018, this area has become more seismically active, according to Krauss. However, on March 6, seismic activity became intense with at least 3 small earthquakes shaking the seabed every hour. In total, researchers detected about 200 earthquakes in one day. “The vast majority of earthquakes are less than one magnitude. They are very small but allow us to track where the vibrations occur, what breaks and the direction of displacement,” Krauss shared.
Krauss said the most likely cause of the earthquake is that the seabed is stretched to its maximum extent and accumulates great pressure. At Endeavor Bank, this happens when two tectonic plates separate by about a meter. The pressure eventually reduces as the magma flows into the thin crust and cools.
An Khang (Follow Live Science)
