Pacific Megaquake: Potential Earthquake, Tsunami from Underwater Fault Threatens 10,000 Residents in US West Coast

A Pacific megaquake in the making can happen sooner or later along the West Coast region of the United States, according to a study earlier in June 2024. This looming threat is caused by an underwater fault line, called the "Cascadia Subduction Zone," which stretches from California to Canada's British Columbia province. The threat includes a potentially powerful earthquake and tsunami.

The US earthquake risk threatens the lives of approximately 10,000 residents across the western region, according to the research paper led by the US. Other scientists also compare the potential Cascadia mega earthquake event to what Japan experienced in 2011, when a strong underwater megathrust earthquake caused a massive tsunami, killing more or less 20,000 people based on official estimates.

While the Pacific megaquake alert is recent, the threat posed by the Cascadia Subduction Zone is not new. For decades, research about the underwater fault line suggests that a seismic potential for a mega earthquake is imminent. Based on historical records of related major tremors within the subduction zone, seismic experts estimate the next megaquake dubbed "The Big One" can occur within the century.

Pacific Megaquake

In the study published in the journal Science Advances on June 7, researchers hinted the lingering Pacific megaquake within the Cascadia Subduction Zone but did not predict a timeline. However, the authors of the paper emphasized the underwater fault line can pave the way for powerful earthquakes every 500 years; the last incident being reported in 1700 when a tsunami struck North America's west coast.

The research led by a team at Columbia University's Lamont-Doherty Earth Observatory says the Cascadia fault line can cause at least a 9.0 magnitude earthquake, comparable to the 2011 Japan earthquake. The findings of the study show that an underwater earthquake and tsunami across the East Pacific Ocean threatens the Pacific Northwest, potentially killing more than 10,000 people and causing widespread damage.

There are no specific hotspots for The Big One across the Northwest US and Southwest Canada, yet the recent study provided a clearer map of which areas are more at risk. Regardless, the earthquake risk is estimated to be confined within these US and Canadian regions, since the 600- to 700-mile Cascadia Subduction Zone runs along the coasts from northern California to southern British Columbia.

Cascadia Subduction Zone

The Cascadia Subduction Zone lies in a tectonic boundary stretching 1,300 kilometers between the Juan de Fuca and Gorda oceanic plates. According to the U.S. Geological Survey (USGS), subduction zone earthquakes are known to generate massive tsunamis and generate earthquakes exceeding magnitude 9 in the Richter scale. This means the next major earthquake in Cascadia is expected to be both life-threatening and disastrous.

Despite our knowledge of tectonic plates and seismic activity, the USGS says that no individual or group has yet to provide a successful earthquake prediction, mainly in terms of specific intensity, time, and location of a tremor.