Earthquake News

Snohomish County is susceptible to a tsunami after the Seattle earthquake.

Within ten minutes of a magnitude 7.5 earthquake on the Seattle Fault, the first wave of a tsunami might reach Snohomish County. The Edmonds ferry port might experience waves that peak at five feet in 15 minutes.

No doubt, Mukilteo would have some consequences as well.

The Washington State Department of Natural Resources (DNR) recently issued a new research examining the effects of a tsunami brought on by a significant earthquake on the Seattle Fault, which included some alarming conclusions.

One of its more alarming discoveries was a wave that might have been more than 40 feet high on Seattle's waterfront.

The study was conducted to assist local and state emergency managers and planners develop and improve response and preparedness plans for a tsunami in the middle of Washington's largest population center and economic hub. It was prepared by geologists within the Washington Geological Survey division of DNR.
The eastern part of Bainbridge Island, Elliott Bay, and Alki Point are among the locations where the analysis concludes that tsunami waves will often reach the shoreline in less time than three minutes.

According to the analysis, the greater Seattle area's shorelines would be submerged to a depth of more than 20 feet by such a tsunami.

"Our outer coast and the communities bordering the Pacific Ocean come to mind most frequently when we think of tsunamis. But there has been a lengthy history of earthquakes on Puget Sound faults, according to the report's Commissioner of Public Lands Hilary Franz.

"While the Seattle Fault has a less frequent history of earthquakes and tsunamis than the Cascadia subduction zone, the effects might be extremely severe. It is crucial that these communities have the knowledge necessary to respond and prepare.

"When we think of tsunamis, our outer coast and the communities surrounding the Pacific Ocean typically come to mind. However, Puget Sound faults have seen numerous earthquakes in the past, according to the report's Commissioner of Public Lands Hilary Franz.

"While earthquakes and tsunamis have historically occurred less frequently along the Seattle Fault than in the Cascadia subduction zone, the consequences might still be very serious. These communities must be equipped with the knowledge required to react and plan.

Many regions experience tsunami waves in a matter of minutes.

The Seattle Fault, which runs east-west through Puget Sound and the city of Seattle, has been the source of multiple earthquakes that have been recorded in the local geologic record. A very large, extremely unlikely earthquake with a magnitude of roughly 7.5 is the scenario considered in this study.

For the purposes of emergency preparedness, it generates the largest possible tsunami from the Seattle Fault.

On the eastern edge of Bainbridge Island, Elliott Bay, and Alki Point, tsunami waves often reach the shoreline in less than three minutes. After the earthquake, there may be a longer than three-hour period of tsunami flooding and strong currents.

Although this analysis indicated that the 6 feet of inundation at the Port of Tacoma would be less than that predicted in earlier studies, it also discovered that in some areas of the port, waves may extend up to three miles inland.

While the Seattle Fault would see the highest tsunami inundation, the study found increased currents and coastal flooding throughout the Salish Sea, from Blaine to Olympia.

The model does not take into consideration local tsunamis brought on by earthquake-induced landslides or tidal stages.

County of Snohomish is not exempt

While the study concentrated on the Seattle Fault, residents in Snohomish County shouldn't assume they are safe from an earthquake in our neighborhood.

A significant rupture has not occurred on the South Whidbey Island Fault, which runs just south of Mukilteo and Picnic Point, in approximately a thousand years.

Similar to the Seattle Fault, it is a shallow crustal fault.

Maximilian Dixon of the Washington Emergency Management Division stated, "Even though the likelihood of (a 7.5 earthquake) occurring in our lifetime is low, it's crucial for families to get ready now" (WEMD).

"The trembling of the ground will serve as your warning that a tsunami could be approaching. Make sure you are aware of the quickest path to the nearest high ground as well as its location. Register for local and tsunami notifications.

At the intersection of Dayton Avenue West and Railroad Avenue in Edmonds, the WEMD installed its most recent pole-mounted tsunami siren, also known as an All Alert Hazards Broadcast tower (AHAB), in the parking lot next to Olympic Beach.

In the event of a tsunami, the sirens provide audible and visual warnings of the impending danger with a wailing audio sound and an intense blue light for the hearing impaired that can also cut through fog and is visible from a great distance, according to the WEMD.

Residents near the shorelines of central Puget Sound would have "minutes to tens of minutes" to leave if the Cascadia Subduction Zone ruptures, according to the Washington State Department of Natural Resources.

Every month on the first Monday at noon, the siren in Edmonds is tested while playing the well-known "Westminster Chimes" tune. The sirens are also tested once a year, with the genuine wail sounding in connection with the Great Washington ShakeOut on the third Thursday in October.

A voice message in English and Spanish stating that the annual test is simply a test will be played after the wail sound.

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