With all the news about Sandy in the Northeast, many learned whether their data centers could ride out a 100 yr flood natural disaster.
In the Pacific NW, the big risk is a megaquake.
Oregon Live estimates the financial impact to just Oregon to be $32bil.
The next great Cascadia subduction-zone earthquake will kill thousands in Oregon and cause at least $32 billion in economic losses unless preparations are radically overhauled, a state panel says.
When, not if, the magnitude-9.0 quake strikes -- let alone an accompanying tsunami -- Oregon will face the greatest challenge in its history, the state earthquake commission said in a 290-page draft report released Monday to The Oregonian.
Now, you may think that Eastern Washington and Eastern Oregon are a safe distance from the threat of a Tsunami. But, when a quake this big hits it affects all parts of a the infrastructure. Pacific NW fiber cables could be broken, water lines break, electrical systems have cascading failures, and diesel fuel is under federal management.
Transmission towers may topple into the river, blocking ships. Fires, landslides and explosions will proliferate. Hydrants and sprinkler systems won't work.
There will be no water or sewer service, no electricity and no ATMs, telephones, television, radio or Internet. Willamette River bridges will be impassable. Food will soon run out.
Responding to the disaster will be difficult, experts found, because of a sort of emergency gridlock. To restore phone service, crews will need restored electricity. To bring back power, workers will require repaired roads and bridges. To fix highways, crews will need restored fuel delivery and distribution.
One issue though is the cascadia earthquakes are spaced out by hundreds of years.
Earthquake magnitude
The Cascadia subduction zone can produce very large earthquakes ("megathrust earthquakes"), magnitude 9.0 or greater, if rupture occurs over its whole area. When the "locked" zone stores up energy for an earthquake, the "transition" zone, although somewhat plastic, can rupture. Great Subduction Zone earthquakes are the largest earthquakes in the world, and can exceed magnitude 9.0. Earthquake size is proportional to fault area, and the Cascadia Subduction Zone is a very long sloping fault that stretches from mid-Vancouver Island to Northern California. It separates the Juan de Fuca and North American plates. Because of the very large fault area, the Cascadia Subduction Zone could produce a very large earthquake. Thermal and deformation studies indicate that the locked zone is fully locked for 60 kilometers (about 40 miles) downdip from the deformation front. Further downdip, there is a transition from fully locked to aseismic sliding.[6]
In 1999, a group of Continuous Global Positioning System sites registered a brief reversal of motion of approximately 2 centimeters (0.8 inches) over a 50 kilometer by 300 kilometer (about 30 mile by 200 mile) area. The movement was the equivalent of a 6.7 magnitude earthquake.[7] The motion did not trigger an earthquake and was only detectable as silent, non-earthquake seismic signatures.[8]
Great Earthquakes
| estimated year | interval |
|---|
|
| about 9 pm, January 26, 1700 (NS) |
780 |
| 780-1190 CE |
880-960 CE |
210 |
| 690-730 CE |
550-750 CE |
330 |
| 350-420 CE |
250-320 CE |
910 |
| 660-440 BCE |
610-450 BCE |
400 |
| 980-890 BCE |
910-780 BCE |
250 |
| 1440-1340 BCE |
1150-1220 BCE |
unknown |
[edit]Earthquake timing
The last known great earthquake in the northwest was the 1700 Cascadia earthquake. Geological evidence indicates that great earthquakes may have occurred at least seven times in the last 3,500 years, suggesting a return time of 300 to 600 years. There is also evidence of accompanying tsunamis with every earthquake, and one line of evidence for these earthquakes is tsunami damage, and through Japanese records of tsunamis.[11]
