Cascadia Subduction Zone: What You Should Know

Source: Washington Emergency Management Division

Earthquakes in Seattle, Washington can be a major source of concern for residents in the Pacific Northwest. Seattle, like many major cities in this region, lies on the intersection of two major fault lines – the Cascadia Subduction Zone and the Seattle Fault. These fault lines are responsible for the majority of earthquakes that occur in the area, and scientists have long predicted that the next big quake is due to hit any day now.

The Cascadia Subduction Zone is a 600-mile long fault line that runs from Northern California to Vancouver Island. It is capable of producing quakes of magnitude 8.0 or larger, which could cause catastrophic damage to the Seattle area. The Seattle Fault is a much smaller fault line, running through the heart of the city, that is capable of producing earthquakes of magnitude 6.0 or higher.

Though scientists are unable to predict exact dates or times when earthquakes will occur, they do have an idea of when the next big quake will hit. According to the Pacific Northwest Seismic Network, there is a 37 percent chance of a major earthquake occurring in the Seattle area within the next 50 years.

The last major earthquake to hit the Pacific Northwest occurred on April 13th, 1949. This earthquake, which registered at magnitude 7.1, was centered near Olympia, Washington and caused extensive damage in Seattle and surrounding areas. The quake caused buildings to collapse, bridges to break apart, and caused a great deal of property damage.

If a similar earthquake were to strike Seattle today, the damage could be far worse due to the city's continued growth and expansion. Buildings constructed before modern seismic codes were enacted are especially at risk of collapsing during a major quake. Additionally, the city's roads, bridges, and other infrastructure may not be able to withstand the force of a large earthquake.

Though Seattle residents can never be completely sure when the next big quake will strike, they can prepare for the possibility. By taking steps to better secure their homes and businesses, they can mitigate the damage and loss that could result from such an event.

Curious whether your property is ready to withstand an earthquake? Book a free seismic assessment with us today and find out.