Unveiling the Birth of New Oceanic Crust: 2,000 Earthquakes Strike Off Canada Coast

A recent surge of seismic activity off the coast of Vancouver Island has raised eyebrows among scientists, with almost 2,000 earthquakes recorded in a single day. This unusual phenomenon hints at a significant geological event: the potential birth of new oceanic crust through a deep-sea magmatic rupture.
Situated approximately 150 miles (240 kilometers) off the coast of Vancouver Island, the epicenter of this seismic flurry lies at the Endeavour site, characterized by a cluster of hydrothermal vents. This region is part of the Juan de Fuca Ridge, where the ocean floor undergoes spreading. Unlike the nearby subduction zone, where tectonic plates collide, potentially resulting in destructive earthquakes, the mid-ocean ridges, such as the Juan de Fuca Ridge, typically produce smaller quakes, seldom surpassing magnitude five.
Zoe Krauss, a doctoral candidate in marine geophysics at the University of Washington, explains that while these earthquakes pose no threat to human safety, they offer valuable insights into the processes underlying crustal formation. The stretching of tectonic plates at the Endeavour site leads to the creation of linear fault lines and the thinning of the crust, facilitating the ascent of magma. Upon reaching the surface, the magma cools and solidifies, contributing to the generation of new oceanic crust.
Continuous monitoring of the Endeavour site, as part of the North-East Pacific Time-series Undersea Networked Experiments (NEPTUNE) conducted by Ocean Networks Canada, has revealed an escalation in seismic activity since 2018. However, the magnitude and frequency of earthquakes reached unprecedented levels on March 6, with approximately 200 small earthquakes occurring per hour and a total of around 1,850 quakes recorded in a single day.
While the majority of these earthquakes register below magnitude one, they serve as valuable markers for tracking crustal movements and fault activity. Krauss suggests that the surge in seismicity may be attributed to the accumulation of stress as the seafloor reaches its maximum stretching capacity. When the plates pull apart by about 3.3 feet (1 meter), the stress is alleviated as magma ascends into the thinned crust, cooling and solidifying in the process. This cycle of stress accumulation and release provides critical insights into the dynamic processes shaping the oceanic crust.

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