Oregon Earthquake Safety & the Cascadia Megathrust

Mark StraussBusiness | Commercial Insurance

As the 2011 magnitude 9.0 Tohoku, Japan earthquake celebrated it’s four year anniversary last week the disaster continues to be a stark lesson for what the potential impact of the predicted Cascadia megathrust earthquake will leave on the Pacific Northwest. It makes one think about Oregon earthquake safety and what safety measures have been put into place.

There is no doubt the threat is real as based on scientific data collected since the 1980’s it’s become a question not if a Cascadia Megathrust earthquake will happen, but a question of when. If you’ve been living under a rock and have had your doubts about this a 2013 publication released by the Cascadia Region Earthquake Group titled “A Magnitude 9.0 Earthquake Scenario” sums up the potential of our earthquake risk perfectly. The publication states “The Cascadia subduction zone is one of the principal sources of concern. Lying mostly offshore, this plate interface is a giant fault—approximately 700 miles long. Here, the et of tectonic plates to our west is sliding (subducting) beneath the North American Plate. The movement of these plates is neither constant nor smooth: the plates are stuck, and the stress will build up until the fault suddenly breaks. This last happened in 1700: the result was an earthquake on the order of magnitude 9.0, followed within minutes by a large tsunami—much like the earthquake and tsunami that struck Japan on March 11, 2011. Stresses have now been building along the Cascadia subduction zone for more than 300 years, and the communities of Cascadia can be certain that another great quake will again shake the region.” Based on the potential devastation of Cascadia it makes one think how earthquake proof is Oregon and what is being done to make certain we survive the projected magnitude 9.0 Cascadia megathrust earthquake and tsunami?

The Oregon Resilience Plan, published in 2012, states“At the current stage, Oregon’s infrastructure has low resilience and is expected to have significant loss of sector services and a slow recovery time.” It’s not a shock to read that statement because the media (which reports legislative activity) seems to be silent in regards to how Oregon is handling our earthquake threat. In stark opposition the city of San Francisco has already passed an ordinance and the city of Los Angeles is proposing to pass a law that requires the retrofitting of earthquake-vulnerable buildings. In addition the city of Los Angeles is preparing a proposal to earthquake proof their water delivery system.

How much earthquake damage would Portland and other major cities suffer? Are you prepared to survive more than two weeks without critical services? Analysis in the Oregon Resilience Plan reveals the following timeframes for service recovery under present conditions:

  • Service: Electricity | Location: Valley | Time to Restore Service: 1 to 3 months
  • Service: Electricity | Location: Coast | Time to Restore Service: 3 to 6 months
  • Service: Police and fire stations | Location: Valley | Time to Restore Service: 2 to 4 months
  • Service: Drinking water and sewer | Location: Valley | Time to Restore Service: 1 month to 1 year
  • Service: Drinking water and sewer | Location: Coast | Time to  Restore Service: 1 to 3 years
  • Service: Top-priority highways (partial restoration) | Location: Valley | Time to Restore Service: 6 to 12 months
  • Service: Healthcare facilities | Location Valley | Time to Restore Service: 18 months
  • Service: Healthcare facilities | Location: Coast | Time to Restore Service: 3 years

As you can see in Oregon’s present state relying on municipal services is unrealistic, the report stated a concern that “a policy of business as usual implies a post earthquake future that could consist of decades of economic and population decline – in effect, a “lost generation” that will devastate our state and ripple beyond Oregon to affect the regional and national economy.”

Our ability to plan, prepare and survive without major relief will be imperative. You should prepare to have food and water for each family member to last at least 4-6 months. In addition each household should have fuel available, if your home has not been built within the past 25 years or is not seismically retrofitted to the foundation you should have supplies to repair your home as it is more than likely your home will sustain damage. If you have earthquake insurance in place for your home make certain you know how to reach your insurance company. One of the most immediate and cost effective solutions you can put into place for the safety of your home is to install a gas earthquake shut off valve, this will eliminate the threat of fire to your home from a break in the gas line. Additional resources can be found on the Earthquake Awareness & Resources page which can help you create an informed plan of action.