Please see "At risk: earthquakes and tsunamis on the West Coast". You can also see the USGS site on earthquake preparation, including seeing shakemaps for your region given hypothetical megaquakes.

No, your buildings and bridges in Portland would not be destroyed, unless they're in violation of the earthquake code that went active in the 80s (with retrofits required by the 00s).

Yes, you should be prepared to survive on your own for 72 hrs, particularly with respect to food, water, and medications.

The problem is: at 8+ magintude, all plans go to crap...

Actually, no. Vancouver is located near a triple-plate junction, and is susceptible to deep magnitude 9 subduction quakes with minimal surface shaking (akin to Chile), or shallower magnitude 7s with a lot of surface shaking. Locally, a magnitude 7 is a lot more problematic, although a magnitude 9 would put everyone else on the rim on tsunami-watch.

Richmond and the unconsolidated saturated sediments they live on below sea water behind a dyke is pretty much out of luck in prolonged shaking, as the liquefaction means they'll discover they built on oatmeal. The only way to earthquake-proof that is to keep Richmond entirely agricultural.

But for the city proper, it's pretty much set. Vancouver is built on glacier-compressed sediment, and once you've had 2km of ice squishing everything flat, as far as earthquakes are concerned, it's pretty much bedrock. The engineered fill around False Creek/Granville Island/the downtown docks are likely to have more problems (honestly, I'm concerned about those nice, huge cranes toppling under a bit of liquefaction, exactly like waterfront in Haiti), but as far as "places with people" go, the biggest danger should be the shower of broken glass in the city core. Even personal preparedness is fairly high: approximately 2,000 students per year pass the intro to disasters course at UBC; I don't have the numbers but I'd guess at least a few hundred take the equivalent course at SFU.

Vancouver Island protects the mainland from tsunami; the only real tsunami-danger east of the island is locally in the fjords if the earthquake triggers a landslide (likely things will fail; not so likely anything big enough will go in any one place to really cause a threatening seche). As for the west coast of the island, this past year's Chile-warning was a good practice run. The last-mile notification is still bumpy, but getting better.

Victoria (on the south tip of Vancouver Island) worries me more -- the current subduction has buckled the island up by approximately 15m, which is an awful lot to deal with if it all slips at once. This is made more complicated by the large proportion of the elderly (Victoria is a major retirement destination in Canada), who have lowered resiliency in emergencies.

I share your exasperation with the lack of popsci understanding of Mars' variable temperatures & pressures.

When I used to run planetarium shows for kids, I used to explain the temperature gradient by telling them, "If you stood on Mars, you'd wear sandals and a parka, since your feet would be as warm as a summer day but by the time you reached your head it'd be colder than winter in Antarctica!" which, although on the "tiny lies of oversimplification" side, is true-ish and a vivid enough image that they remembered months later.

I love that "above some critical threshold" is listed like a mysterious or complex thing. It's the angle of repose, the angle that a material naturally sits at when you let it fall from a height and pile up. It might be, if things are very complicated, the angle of repose + cohesion, but then you're back at water-based theories again since water is the easiest way to remove cohesion and trigger failure.

I also really like that the experimenters managed to recreate a sand flow in their lab. Of course they did. The field of prior research involving laboratory sand flows is immense, especially if you start including the ones with tiny glass beads of carefully varied diameters instead of sand. The only problem is thioxtropy -- landslides are renowned for having material that exhibit viscosity inversely proportional to velocity -- which is not easily replicable in small-scale lab settings.

I'm not sure if this is a, "Physicists discover what geologists already knew" moment, or a "Journalists are puzzled by the mundane mysteries of science," or what, exactly, but if you want to learn more about landslides on Mars, check out geotechnical journals starting with Lucchitta 1978 (Bulletin of the Geological Society of America, v89, pg 1601) and work your way forward. As the lunar and Martian landslides discredited an entire set of excess mobility theories, they're very well described and discussed.

As far as detecting tsunamis from space, while not what the article poster is suggesting, would be a better use of orbiting lasers - detection of small rise in sea-level over a large area would, presumably, be a phenomena easily spotted from space.

...although more sensible than the article's idea, this one also won't work. The ocean isn't anywhere close to smooth -- follow the links on the difficulties of calibrating satellites from this 2007 article for an intro, then look up info on calculating the geoid -- and tsunamis are very, very small in open ocean.

But that's alright, since the science on predicting where the waves will go and when they'll arrive is incredibly good. The science on how big they'll be when they get there... now, that's an interesting problem worthy of more research & innovation!

If you want to take the parent's suggestion of studying this stuff seriously, some pointers:
- Check out U of Colorado's Natural Hazards Center. They have info on the major disaster research mailing lists, and put out a very good bulletin on the latest and greatest of ideas.
- A tsunami notification system (via email or SMS) already exists; it has the same inherent flaws as any other automated tsunami warning in that it only activates for earthquakes (not landslides) and lacks in expert judgment on if an event is likely to occur.

As for the easiest, cheapest, and most effective means of reducing tsunami danger: let the mangroves regrow. Mangroves act as an absorbing buffer; the areas with the least destruction and deaths from the Boxing Day Tsunami were all where the mangroves were intact. Tourist destinations tend to pluck the mangroves (huge beaches are so much more attractive for hotels), removing that protection. For the ugliest enactment of this risk-increasing policy, check out the mudflats of Cairns, Australia.

Just a pedantic little thing -- as a geomorphology instructor, I can tell you that rivers and coastlines are very, very likely to have changed. Check out pretty much any river mouth in Victoria, Australia, or any island off Maine, US in google earth vs google maps satellite mode for examples of how much they can change inside of just a few years. If something catastrophic has happened (big storm, big earthquake...), huge changes can shift the coastline inside of hours.

If you're going to use geomorphic features for your geocoding, find out what's most stable in your region (keyword search academic journals for geomorphology + your location + change and see what doesn't pop up, or ask a local university geo prof). Vegetated topography can be pretty stable over decades, especially if you only need relative shapes.

Thank you. Thank you, thank you, thank you.

I'm already cross-eyed from spending the last week pushing to finish a big project and keep being vaguely bemused by basic human interaction, then this came up and I was completely lost. The rant was both necessary and entertaining. So: thank you.

The geotechnical/geological engineers have also been treating soils as fluids for years -- check out any papers by Oldrich Hungr or Stephen Evans on landslides. Neil Balmforth, a geologist/mathematician, has piles of papers on fluid dynamics of small grains (sands or glass beads).

As a physicist working in earth science, yes, it is really nice to finally have some more solid reasons behind treating soft soils as fluids besides "because it works," but I disagree with the summary's claim that the discovery will lead to a whole new approach to soil sciences since it's already been treated as true for ages.

Exactly! It's in the key words: "cause" is the underlaying geology/structures/faults/etc that made it possible for this chunk to fail, "trigger" is why it happened at this particular time. If a trigger didn't happen (the dam wasn't built), then something else would act as a trigger later. Yes, the exact nature of the outcome would be different due to the intensity & distribution of the triggering event and other complex interactions blah blah blah, but it still would've been an earthquake. One of the big landslide bloggers posted an informal response to the academic article the news stories are based on. I thought his point about an artificially-triggered earthquake having liability consequences was interesting. I don't know the stats on death & damage for this event, but it'd certainly be enough to bankrupt anyone who was found fully or partially responsible for the disasters. I can see the usual suspects of conspiracy-theorists calling foul if the dam-triggering-earthquake theory is rejected by other scientists. After all, it wouldn't have anything to do with evaluating theories based on observations; the scientists would be protecting the geological engineers/regional planners/etc from bankruptcy, right? ;)