Cascadia Earthquake: Part 2 Timelines, Japan, Food and Bridges

1200px-HawthorneBridge-PanoRunning time: 1 hour 3 min.

Click here for Part 1:Introduction, maps and fuel

Today we go over the timeline of past great earthquakes, link between Japan and Oregon, Infrastructure/Risk.  The page numbers are the electric (vs. print out) number and not the true page numbers.

Oregon Resilience Plan—please click and follow along.


“Oregon’s buildings, transportation network, utilities and population are simply not prepared for such an event. Were it to occur today, thousands of Oregonians would die, and economic losses would be at least $32 billion.” Pg 26

 Intervals of Great Quakes

The time interval between previous earthquakes has varied from a few decades to many centuries, but most of the past intervals have been shorter than the 313 years since the last event. It is simply not scientifically feasible to predict, or even estimate. when the next Cascadia earthquake will occur, but the calculated odds that a Cascadia earthquake will occur in the next 50 years range from 7-15 percent for a great earthquake affecting the entire Pacific Northwest to about 37 percent for a very large earthquake affecting southern Oregon and northern California. Pg 30

The simulation shows that Oregon would experience shaking very similar to the shaking that northern Japan endured in 2011. As indicated in Figure 1.4, areas along Oregon’s coast would experience severe to violent shaking, while cities along the I-5 corridor would experience strong or very strong shaking. East of the Cascades, shaking would be light to moderate. In all areas, the strong shaking would last from two to four minutes. Pg 31

Oregon’s Infrastructure and Risk

This means that the majority of buildings in Oregon have not been designed to resist the shaking from a magnitude 9.0 Cascadia earthquake. This widespread vulnerability of Oregon’s buildings is grimly illustrated in the Statewide Seismic Needs Assessment completed by the Oregon Department of Geology and Mineral Industries (DOGAMI) in 2007.pg38

Of the 2,567 highway bridges in the Oregon Department of Transportation (ODOT) system, 982 were built without seismic considerations, and of the rest, only 409 were designed specifically with consideration of Cascadia subduction zone earthquakes.


“In 2011, Oregon’s economy produced nearly $195 billion in goods and services (US Bureau of Economic Analysis, Regional Economic Accounts). The state’s firms and agencies employed over 2.2 million people who earned over $104 billion in compensation (Bureau of Economic Analysis, Regional Economic Accounts). While these workers produced goods and services in a wide variety of industries (including agriculture, logging, wood products manufacturing, computer and electronics manufacturing, metals manufacturing, company management, and tourism), every industry depends on various factors that could be disrupted by a Cascadia event.” pg 45

“Because stores are routinely resupplied several times each week, the amount of food actually held in an individual store is probably no more than what is required to supply the surrounding neighborhood for a few days. In particular, fresh fruits, vegetables, and dairy products are typically replenished several times a week, so the quantities kept in stock are not large. With supplies already limited, a related concern is that people will hoard food out of fear that stores will run out completely. In the near term, such hoarding will exacerbate the erosion of the food supply.” pg 55

“Before a business can reopen following a Cascadia earthquake, the building it occupies has to be certified to be structurally safe, it has to be served by municipal and private utilities and the communications  infrastructure must be operating. A business that cannot reopen within a month of a major earthquake or other disaster resulting in extended service disruption will likely never reopen at its previous location”                                 (see Figure2.10).page 58

“If a Cascadia earthquake occurs during the workday (a one in three chance), workers will be in their offices or industrial plants during the event. In areas of the state where the Willamette River bisects the cities — Portland, Salem, Albany, Corvallis/Lebanon, and Eugene/Springfield —it is likely that a large number of workers will be trapped on the “wrong side” of the river.” page 62

Disaster song by Mc Frontalot

Related Posts

Leave a reply