Beyond the Drill: Urgent Need for Washington Earthquake Readiness

The Great Shakeout Drill was today in Washington State, but do you really understand the dangers we face if the Cascadia Subduction Zone goes?

Prepare for the Big One: Importance of the Great ShakeOut Drill

The Great ShakeOut drill took place today at 10:17 AM, serving as an essential reminder for communities to prepare for the possibility of an earthquake, a scary reality for people living on the coast of Washington State. Millions participated in this one-minute drill to practice vital safety measures during an earthquake. While this brief exercise was important, it’s crucial to recognize a Cascadia Subduction Zone earthquake could last significantly longer than the drill and be much more dangerous than most people realize.

The Cascadia Subduction Zone, stretching from Cape Mendocino, California, to Vancouver Island, British Columbia, is a megathrust fault capable of producing extremely powerful earthquakes, potentially reaching a magnitude of 9.0. Historical evidence shows that the last major event occurred on January 26, 1700, and its resulting tsunami was recorded as far away as Japan with an estimated 100-foot wave. Scientific studies indicate that this zone is currently "locked" by friction, slowly building strain that will eventually lead to a catastrophic event.

The statistics are alarming: the Cascadia Subduction Zone generates a major earthquake approximately every 300 to 600 years, but intervals have ranged from as low as 200 years to as high as 1,000 years. Recent studies suggest a 7-15% chance of experiencing a magnitude 9.0 earthquake in the next 50 years, especially in the southern portion of the zone, which is historically more active. Watch the video below of multiple simulations of what an 8.0+ earthquake could be like.

The Cascadia Earthquake Could Last 4 to 6 Minutes

The impacts of a Cascadia earthquake will be profound and widespread. Ground shaking would affect areas from Northern California to British Columbia, with intense shaking lasting 4 to 6 minutes. This duration, combined with the low-frequency shaking characteristic of subduction zone quakes, poses a significant risk to tall and long structures, increasing the potential for devastating damage. Most of the northern west coast has older buildings built before anyone knew the subduction zone existed, which will likely collapse with the expected large earthquake.

Economic losses are projected to be unprecedented, with estimates for Oregon alone exceeding $32 billion, almost one-fifth of the state’s gross product. Fatalities could range from 650 to 5,000 or higher, with over 27,000 individuals potentially displaced from their homes. Essential services will be disrupted for extended periods, impacting water, electricity, and healthcare facilities.

In addition to the earthquake risk, residents in coastal areas must also prepare for the possibility of a tsunami, which could strike within 15 minutes of the earthquake. Estimates have the tsunami wall be 100 feet or more. Some scientists say most everything west of I-5 will be washed away from below Seattle to northern California. The video below shows the direct impact on coastal communities the large wall of water will have just minutes after the 9.0 earthquake. That is one major reason why knowing your evacuation routes out of that area quickly is vital to your family's survival.