It is interesting to see all the California bashing in a thread that involves the Cascadia Subduction Zone, which is centered in the Pacific Northwest, basically Oregon and Washington. I suppose that California is indelibly associated with earthquakes in the popular mind, at least in the USA.

Two of the largest shakes, the 1964 Alaska quake, and the 1812 New Madrid event, in the lower Mississippi valley, had nothing to do with California directly. California is generally more active, although the large events here, historically at least, have been of somewhat lesser magnitude. What is of direct interest to Californians is the historically quiet southern third of the San Andreas fault, which hasn't moved in recorded history, and is therefore somewhat "overdue" Fountain's caution with respect to this concept are absolutely correct.

So, if one happens to live in California, you don't need to go to Las Vegas to gamble. Just wait for the next Big One. And while you are waiting, take comfort that Las Vegas is getting closer all the time.

"So California drops into the sea."

I've actually got a large surfboard resting on the side of my house.
Ready to go, captain :-)

Pete2

The Casscadia event is getting a lot of attention in Oregon.

The drum beat is getting louder.

In Central Oregon (the Bend Region) a big concern is that should a major event occur a lot of people from the western half of the state will try to evacuate here.

The Red Cross doesn't have the supply support or materials in place to manage such an event.

Blake

www.outdoorquest.blogspot.com

Goodthing Prineville is close by,California's Home Depot stores get 99% of their Plywood from that town.

I lived just west of the Los Angeles area in the adjacent county during the 1994 Northridge quake. Our locality lost power for a day. There was no discernible movement of refugees out of Los Angeles into our area. When you think about it, how do you "flee" an earthquake... After the event. most people will try and patch up and rebuild, although U-Haul traditionally does great business in the weeks after a big shake - people moving to Kansas to avoid quakes. I have talked to ex-Floridians who have moved to SoCal to avoid hurricanes - talk about jumping out of the frying pan into the fire.

Migrations / self-evacuations after a quake depend entirely on the scenario - a 9.0M CSZ quake in November-February when the temps are 32-42 F and its wet out may cause a lot of displaced to try to get away. The focus of the initial response is to shelter folks so they don't die, then its like running a farm - feed them and water them and handle their sewage. You want your house to remain habitable, but if it doesn't crowding in with neighbors or in a nearby church, school or community center to get out of the rain will do, believe me. Ask yourself, if you're lucky and your house survives a 9.0M, are you really going to turn away the neighbor - or stranger - at your door? July when you can survive over night and not get rained on gives you more possibilities - as long as you can eat and have something to drink, you probably are going to stay close to home. You may send your family out to Aunt Martha's, and the kids could be expected to stay 4 counties over to go to school the next year.

During the Vancouver Olympics Washington EMD and various other agencies ran a drill simulating a rapid forced migration across the border of thousands of Olympic visitors, I think the identified threat was a terrorist attack, but the logistics are all the same - how many can cross the border per hour, how fast they can travel, how far before they need to stop for the night and bed down, etc. Dealing with any migration has a lot of similarities - how many are at risk from an event, how many are detected along major traffic routes out of the area, how far can they travel before they have to bed down. You open shelters and offer assistance along those routes, people will stop, or find their own shelters, food and water. I can believe that Bend OR doesn't have the resources to assist Western Oregon after a CSZ event, but then neither does anyone, not without a bit of planning.

From just an earthquake? Probably no sudden mass migration. But if we're talking CSZ, a tsunami or series of tsunami could flood hundreds of square miles of coastline and push people inland in a hurry. Or a strong earthquake near Sacramento, CA could collapse the extensive levy system there, flooding much of the metro area and causing people to flee. And under the right conditions, a big, out of control wildfire could have a huge front that forces many thousands to flee in a hurry.

A slower unfolding but also plausible scenario is a shortage of water in Southern California if the water supplies imported from Northern California and Colorado are disrupted by a quake for an extended period of time. So, a strong quake near Sacramento or out in the desert along the San Andreas might not cause that much damage for the people in the LA/OC metro area, but severely disrupt water supplies and prompt SoCal residents to leave for greener pastures if most water imports are cut off. There are extensive local reservoirs but those won't last forever, nor are there enough ground water supplies to support everyone in the region.

Oh, and considering the ongoing troubles at the San Onofre nuclear power plant and the tragedy of 3/11/11 in Japan, a nuclear accident triggered by an earthquake could release radiation and cause a major migration. There are reports that the Japanese government considered evacuating up to 40 million people due to the Fukushima meltdown. Where do you send 40 million people on short notice?

My point was that it doesn't seem that historically earthquakes have triggered large movements of victims fleeing the scene of the devastation, but I am certainly no expert on the situation. Can someone cite examples of large movements of earthquake refugees?

According to the Virtual Museum of the City of San Francisco, three-fourths of the city's population was evacuated after the Great 1906 Earthquake:



According to this website, after the 7.9 Sichuan earthquake in China: "At least 15 million people were evacuated from their homes and more than 5 million were left homeless."

i'm surprised that folks in OR are worried about a potential evacuation from the western side of the state. I would think that Oregon has enough farms, local communities and resources to cope with displaced people. Seems like everybody should get fed - it may take a little while. But it should happen.

As far as LA goes ... I tend to think that the human response after a giant earthquake may be the dominant factor in an emergency, rather than just the earthquake itself. I honestly cannot predict how people will do. But it's not hard to speculate that families will run out of fresh water in a few days. And at that point they either fight with each other over the remaining (very) scarce resources ... or they try to get out. However, walking out of LA is no mean feat, and could be a grueling trek. Especially for families with children. An escape route going East would take them into the desert ... not attractive from a dehydration point of view. South or north might be better. It's hard to know what will happen to LA - probably depends upon whether there are large-scale fires (after the quake) and large-scale rioting.

Pete2