BRITISH COLUMBIA, Canada — A 5.7-magnitude earthquake struck off the coast of Vancouver Island on Thursday morning, just a day after a 4.4-magnitude quake hit in a nearby area.
The United States Geologic Survey (USGS) recorded the earthquake at 9:15 a.m. on the morning of July 4th, just over 250 miles west of Victoria. In total, there have been 10 earthquakes of at least 4.0 magnitude in the waters west of Puget Sound in the past 24 hours.
The National Weather Service shared a social post following the earthquake that no tsunami alert was being issued for this quake.
It appears to have been the highest-magnitude earthquake in the Pacific Northwest since at least January, per USGS available data.
Earthquakes near western Washington
Many earthquakes in and around Washington state are linked to the motion of the Juan de Fuca Plate and the North America Continental Plate moving against each other as the Juan de Fuca Plate slips beneath the North American continent, according to PNSN. This is called the Cascadia Subduction Zone.
According to the Washington State Department of Natural Resources (DNR), earthquakes happen in Washington every day, but most are too small to be felt. The state has the second highest risk in the U.S. of experiencing a large and damaging earthquake because of its geologic setting.
The Pacific Northwest typically experiences three types of earthquakes:
- Shallow fault quakes: Ruptures in faults located in the upper 18 miles of the Earth's crust. These earthquakes typically last 20 to 60 seconds and shaking is localized to the area near the fault, according to the DNR.
- Deep earthquakes: Deep faults happen when two tectonic plates collide and one plate slips beneath the other one. These quakes can impact a large area but are less intense.
- Subduction zone earthquakes: This earthquake results from the tension of an oceanic plate slipping beneath a continental plate. When enough stress builds, the fault will rupture, releasing a massive amount of energy. The Cascadia Subduction Zone has the potential for these types of earthquakes and has ruptured in the past. It is one of Washington state's biggest hazards, according to DNR.