History won’t let us forget we’re due for mega earthquake
Jan 26, 2018, 2:44 PM | Updated: 3:29 pm
(File, MyNorthwest)
(File, MyNorthwest)
Around 9 p.m. on Jan. 26, 1700, one of the largest earthquakes the Pacific Northwest has ever experienced struck.
WATCH: ‘Big One’ simulation
The quake is believed to have been comparable to the magnitude 9.2 earthquake of March 27, 1964, in Alaska and the magnitude 9.2 quake of 1960 in Chile.
The ground shook for up to five minutes and created a tsunami that traveled across the Pacific Ocean, eventually hitting the east coast of the main island of Japan.
Researchers believe the earthquake was linked to the Cascadia Subduction Zone. The subduction zone is the area where the Juan de Fuca tectonic plate and North American plate overlap. When it hit, the coastline along the Pacific Northwest is believed to have dropped as much as 6 feet.
There hasn’t been a Cascadia Subduction Zone earthquake since that day in January of 1700. Scientists say a magnitude 8.0 quake happens every 250 years on average. That means we’re “overdue” for a large-scale earthquake.
The magnitude 7.9 Alaska quake on Tuesday was just another reminder of the reality we face.
There are efforts underway to better prepare us for a mega-quake. The Shake Alert system, for example, is moving forward and will eventually be used to shut down critical infrastructure and warn people prior to a large quake.
A visit to the earthquake simulator
Cities are also preparing for a devastating quake through retrofitting. However, much work has yet to be done on that front. In Seattle, for example, the city’s Department of Construction and Inspections compiled a list of more than 1,100 buildings that are in danger of being destroyed or severely damaged during an earthquake. The problem: there is no mandatory requirement for property owners to retrofit them.
As Reuters reported after the Alaska quake on Tuesday, there are concerns that the region is also under-prepared for a tsunami. Scientists, Reuters reports, have only pinpointed about half the areas where tsunamis are likely to come ashore after a Cascadia-related earthquake. The state’s chief hazard geologist said “a lot needs to be done” to prepare for a tsunami.
Even the tsunami warning system has much to be desired. Though people in Alaska received warnings to move to higher ground for a potential tsunami, some residents on Washington’s coast received no warning whatsoever because the threat didn’t raise to the level requiring an alert.
