Since the frequency of earthquakes there is relatively low they use lower requirements for building strength.
I am absolutely certain you are mis-remembering, or the popsci distorted the engineering in their efforts to make it interesting for public consumption. I attend a lot of disaster conferences. I sat in on a policy session at the rock mechanics conference in Vancouver in the fall of 2007? 2008? where at least 100 global experts gathered specifically to discuss earthquake building codes in subduction zones (including the PNW and Japan). Low-frequency, low-intensity earthquake zones have lax codes, yes, but low-frequency high-intensity zones currently have very, very strong codes that at this point are only revised upwards to be more strong. (The iconic image of the Japanese low-rises toppling over prompted a set of revisions for building on sediment.)
...topple almost every building within a hundred miles of the epicenter.
Again, not a chance that's an accurate geotechnical assessment of any urban center in Canada or the United States. In part this is because our assessments have more to do with the hypocenter (the actual location of rupture) than the epicenter (the surface projection of the hypocenter). In California, the two are often close-enough to being the same, but in subduction zones the depth of the hypocenter has a huge impact on the type of shaking that will be felt. As I've explained in other comments in this thread, the PNW can get shallower magnitude 7 earthquakes that will cause a devastating amount of surface shaking in a very small area, or deeper magnitude 9 earthquakes that will cause less severe surface shaking over a very wide area. It is geologically not possible to have severe surface shaking over a large region*.
* This is true globally, unless you have local superficial geology that intensifies shaking. Mexico City is located in a sediment-filled basin that amplifies ANY surface waves that go anywhere nearby.
Wow! I didn't know the Hawaiian submarine landslides and resulting tsunamis were in the common knowledge. I've done a tiny, tiny bit of work modeling consequences of that one, and always figured it was a reliable "danger you've never heard of."
...mentioning that the state governments up here were taking interest in learning from the lessons of that quake to prepare better for our next big quake.
You would not believe how many quickie-conferences are popping up this summer addressing small little details in response to that earthquake.
The Yellowstone Caldera is not related to the subduction melt. Mount Saint Helens, Mount Rainier, and the rest of that volcanic chain are related, but plates shifting about in an earthquake doesn't increase or decrease rates of melting.
A bit off topic, but a fun bit of trivia: oceanic plates produce non-violent volcanoes (like Hawaii), continental plates produce highly violent volcanoes (like Yellowstone, although most are very very very small), and ocean melt passing through continental plate produce intermediate volcanoes (like Mount Saint Helens) which are technically less violent than purely andesitic volcanoes, but have larger volumes of magma so are the most destructive. (For the chemistry nerds, it has to do with percent-silica & trapped gas).
A few factual corrections, although I agree with the tone.
The earthquake building code for the United States is the same throughout the country, but it zones the country by expected earthquake risk. California is in a high-risk zone, but so are several other locations in the country. BC, California, and Japan all have fairly comparable building codes. So yes, California's code is very, very good. But it's not, technically speaking, "the best."
Next, California has relatively small translational earthquakes caused by the plates rubbing past each other. This leads to intensely focused, fairly shallow earthquakes, similar to that experienced by Haiti. It's common for one city to be hit hard (LA during the Northridge Quake, SF in '89...) and the surrounding region to be pretty much unaffected.
The Pacific North West and Chile have subduction earthquakes, also called megaquakes because of their incredible magnitudes. These earthquakes are caused by one plate subducting under another, and lead to deep earthquakes with less-intense shaking felt over a larger area. They are also commonly associated with tsunami-generation because of underwater vertical displacement (Sumatra was another subduction quake).
Geologically, the regions you're comparing have very different causes for earthquakes, very different types of shaking felt at the surface, and different impacts on the rest of the rest of the world.
Lots of big differences, from geology to building code to economic resilience. If you're curious, I bet it'll be a hot topic in all the big geo/policy conferences this year (AGU December 2011 in SF will probably have a whole session on it)
1. Geology: Haiti was a shallow, translation earthquake. This means that the surface shaking was intense & prolonged over a focused area (just the city). Chile was a deep, subduction earthquake. This means the shaking was spread over a larger surface area (half the country). 2. Awareness: Haiti's fault was only identified in the past few years. Chile's known it's in earthquake country forever. 3. Building code: Haiti did not have an earthquake building code. Chile's earliest earthquake-safe building practices pre-date the foundation of the country....and then continue on into the development, economic resiliency, and so on.
Pretty much the only thing the two events had in common was, "the ground shook," and "it happened in the same year." Nothing else is comparable.
One of the awesome things about earthquakes is that although we aren't so good at predicting exactly when they'll happen, we are very, very good at predicting where (where stress has built up, usually at the ends of the most recent rupture zone) and what type of shaking will occur.
Earthquake codes are designed to match the intensity and style of shaking not just for earthquakes with local epicenters, but what sorts of shaking they'll experience from elsewhere. The United States and Canadian codes were both revised repeatedly long after the threat of PNW mega-quakes were established. The building codes are very, very good (Japan's are also amazing), and quite well-enforced. Sure, we might have a few undetected defectors, like the high rise in Chile, but pretty much every public building in the entirety of BC that needed to be retrofit has been already.
The parent article is not new news. Not even slightly new news. Not even remotely new news. This news is so old, my parents met, got married, had a few kids, then I was born, grew up, went to a bunch of schools, and became a certified disaster expert since it first became well-known to the disaster-community (& it became well-known to the non-expert residents still before I was born). The only reason it's making the popmedia rounds now is because Haiti and Chile raised awareness of the potential devastation of earthquakes.
Also, that Haiti's quake was a shallow translational earthquake, so had lots of surface shaking, while Chile had a deep subduction quake with minimal surface shaking.
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.
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?;)
There are two ways of detecting exoplanets:
1. Wobbles -- what you explained: watch a star for deviations in its orbit by observing tiny redshifts and blueshifts. Our own sun does a little jiggle thanks mostly to Jupiter.
2. Dimness -- what they did for this object. Watch a star for dimming as something passes in front of it, although you have to be careful of other causes of temporary decreases in luminescence (like sunspots).
In both cases, it really needs repeated observations over time to establish that it's an orbital event and not something random. In the good ol' days of exoplanet discovery when the equipment wasn't so hot & we expected to find planets pretty much like ours, it took a whole lot of observations before anyone was willing to take the risk of announcing a discovery. Now, with better equipment making it easier to detect hiccups in a star's routine and a more open attitude about how planets behave, discoveries are being announced a lot earlier in the observation process.
To be fair, TFA does give itself a whole lot of wiggle room in interpreting the data. It just fails to mention that follow-up observations aren't confirming the orbital parameters of the assumed planet.
This was followed up on the astro mailing lists as faulty data -- the observers mistook sunspot-dimming for a planet passing in front of the star. The correction hasn't made it to journalists yet and the science article is still in draft, so no link-to-reference, sorry!
Planetary formation theory is fragmented and deeply in need of reworking (anyone want a phd topic?), but not to incorporate Jupiters in Mercury-orbits (yet).
I've been spending a lot of time hanging out with the evolutionary psychology research group, and they've taught me that the (evolutionary-)point of boobs is to camouflage the menstrual cycle. The basic logic is:
- if a male can tell a female's cycle, he'll spend all his time and energy on impregnating her at her most fertile(and keeping the other males away) but when she's not fertile dump her.
- for most primates, breasts swell during the fertile point in the cycle (as for why that would indicate a good mating partner, check out some other posts)
- to keep a guy around, women need to hide when they're fertile and when they're not so their breasts are swollen all the time (thus, boobs).
Okay, I'm not an evolutionary psychologist myself so I'm probably missing bits & it's not really relevant to the article, but it's tangentially related and I thought it was a neat theory. It does make me wonder if there's other examples (or counter-examples) of hiding fertility cycles and how it relates to mating/group structure.
It also makes me wonder if a version of the theory will pop up in a how-to-keep-your-man book or magazine some day -- "Now girls, make sure he never knows if you're using birth control or if you're on your period, or he'll be evolutionarily driven to cheat on you!"
The Initiative is already being rolled out. I'm at one of the first-round target schools in a department that won CWSEI funding, and have been involved in several of the curriculum-revision committees.
CWSEI is focused on undergraduate science education, both for science students and non-science students. The general plans is:
1. Articulate what we want students to learn
2. Figure out what they're actually learning
3. Fix things
4. Share everything that works with other department/schools
Step 1 has been pretty easy for the courses I've been involved with revising, although it can get pretty funny to see different schools of thought battling it out over what matters most (facts? ability to apply in novel situations? general "science" mindset? problem-solving?)
Step 2 is a bit of a nightmare, but is necessary to figure out if you're actually being effective or not (Step 2 & 3 are iterative until satisfactory, then progress to Step 4). How do you effectively test comprehension vs test taking-ability vs fact retention? It's a bit easier to fix the "Did we teach them or did they already know?" by doing before-and-after tests, but that still doesn't eliminate the keeners going out and self-teaching (no bad prof has ever defeated my desire to learn!)
Step 3 is also a challenge -- in big classes (Natural Disasters can have up to 400 students) it's almost impossible to have one-on-one interactions, they're undergrads so presumably parental-involvement isn't key for learning, the TA-hours to do good grading of neat projects is prohibitive, etc. This is where tech solutions come in: if everyone takes immediate multiple-choice quizzes throughout via clickers, or has to talk with their neighbours to decide on an answer, then we've got them interacting/thinking/talking inside class hours....kinda lame so far, but if you've got good ideas that fit within our ridiculous budget, I promise I'll try 'em out!
For Step 4, what works? U Colorado's physics department was where Carl started this idea, so they've got some pretty cool toys that help students practice concepts they heard in lecture even outside of lab sections. As for my department, no solutions yet...
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Since the frequency of earthquakes there is relatively low they use lower requirements for building strength.
...topple almost every building within a hundred miles of the epicenter.
I am absolutely certain you are mis-remembering, or the popsci distorted the engineering in their efforts to make it interesting for public consumption. I attend a lot of disaster conferences. I sat in on a policy session at the rock mechanics conference in Vancouver in the fall of 2007? 2008? where at least 100 global experts gathered specifically to discuss earthquake building codes in subduction zones (including the PNW and Japan). Low-frequency, low-intensity earthquake zones have lax codes, yes, but low-frequency high-intensity zones currently have very, very strong codes that at this point are only revised upwards to be more strong. (The iconic image of the Japanese low-rises toppling over prompted a set of revisions for building on sediment.)
Again, not a chance that's an accurate geotechnical assessment of any urban center in Canada or the United States. In part this is because our assessments have more to do with the hypocenter (the actual location of rupture) than the epicenter (the surface projection of the hypocenter). In California, the two are often close-enough to being the same, but in subduction zones the depth of the hypocenter has a huge impact on the type of shaking that will be felt. As I've explained in other comments in this thread, the PNW can get shallower magnitude 7 earthquakes that will cause a devastating amount of surface shaking in a very small area, or deeper magnitude 9 earthquakes that will cause less severe surface shaking over a very wide area. It is geologically not possible to have severe surface shaking over a large region*.
* This is true globally, unless you have local superficial geology that intensifies shaking. Mexico City is located in a sediment-filled basin that amplifies ANY surface waves that go anywhere nearby.
Wow! I didn't know the Hawaiian submarine landslides and resulting tsunamis were in the common knowledge. I've done a tiny, tiny bit of work modeling consequences of that one, and always figured it was a reliable "danger you've never heard of."
...mentioning that the state governments up here were taking interest in learning from the lessons of that quake to prepare better for our next big quake.
You would not believe how many quickie-conferences are popping up this summer addressing small little details in response to that earthquake.
The Yellowstone Caldera is not related to the subduction melt. Mount Saint Helens, Mount Rainier, and the rest of that volcanic chain are related, but plates shifting about in an earthquake doesn't increase or decrease rates of melting.
A bit off topic, but a fun bit of trivia: oceanic plates produce non-violent volcanoes (like Hawaii), continental plates produce highly violent volcanoes (like Yellowstone, although most are very very very small), and ocean melt passing through continental plate produce intermediate volcanoes (like Mount Saint Helens) which are technically less violent than purely andesitic volcanoes, but have larger volumes of magma so are the most destructive. (For the chemistry nerds, it has to do with percent-silica & trapped gas).
300-500 years, with the last big one in near Christmas in 1700.
A few factual corrections, although I agree with the tone.
The earthquake building code for the United States is the same throughout the country, but it zones the country by expected earthquake risk. California is in a high-risk zone, but so are several other locations in the country. BC, California, and Japan all have fairly comparable building codes. So yes, California's code is very, very good. But it's not, technically speaking, "the best."
Next, California has relatively small translational earthquakes caused by the plates rubbing past each other. This leads to intensely focused, fairly shallow earthquakes, similar to that experienced by Haiti. It's common for one city to be hit hard (LA during the Northridge Quake, SF in '89...) and the surrounding region to be pretty much unaffected.
The Pacific North West and Chile have subduction earthquakes, also called megaquakes because of their incredible magnitudes. These earthquakes are caused by one plate subducting under another, and lead to deep earthquakes with less-intense shaking felt over a larger area. They are also commonly associated with tsunami-generation because of underwater vertical displacement (Sumatra was another subduction quake).
Geologically, the regions you're comparing have very different causes for earthquakes, very different types of shaking felt at the surface, and different impacts on the rest of the rest of the world.
Lots of big differences, from geology to building code to economic resilience. If you're curious, I bet it'll be a hot topic in all the big geo/policy conferences this year (AGU December 2011 in SF will probably have a whole session on it)
1. Geology: Haiti was a shallow, translation earthquake. This means that the surface shaking was intense & prolonged over a focused area (just the city). Chile was a deep, subduction earthquake. This means the shaking was spread over a larger surface area (half the country). ...and then continue on into the development, economic resiliency, and so on.
2. Awareness: Haiti's fault was only identified in the past few years. Chile's known it's in earthquake country forever.
3. Building code: Haiti did not have an earthquake building code. Chile's earliest earthquake-safe building practices pre-date the foundation of the country.
Pretty much the only thing the two events had in common was, "the ground shook," and "it happened in the same year." Nothing else is comparable.
Thank you. I was starting to worry that I was biased about how common basic earthquake safety knowledge is locally!
One of the awesome things about earthquakes is that although we aren't so good at predicting exactly when they'll happen, we are very, very good at predicting where (where stress has built up, usually at the ends of the most recent rupture zone) and what type of shaking will occur.
Earthquake codes are designed to match the intensity and style of shaking not just for earthquakes with local epicenters, but what sorts of shaking they'll experience from elsewhere. The United States and Canadian codes were both revised repeatedly long after the threat of PNW mega-quakes were established. The building codes are very, very good (Japan's are also amazing), and quite well-enforced. Sure, we might have a few undetected defectors, like the high rise in Chile, but pretty much every public building in the entirety of BC that needed to be retrofit has been already.
The parent article is not new news. Not even slightly new news. Not even remotely new news. This news is so old, my parents met, got married, had a few kids, then I was born, grew up, went to a bunch of schools, and became a certified disaster expert since it first became well-known to the disaster-community (& it became well-known to the non-expert residents still before I was born). The only reason it's making the popmedia rounds now is because Haiti and Chile raised awareness of the potential devastation of earthquakes.
Also, that Haiti's quake was a shallow translational earthquake, so had lots of surface shaking, while Chile had a deep subduction quake with minimal surface shaking.
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? ;)
There are two ways of detecting exoplanets:
1. Wobbles -- what you explained: watch a star for deviations in its orbit by observing tiny redshifts and blueshifts. Our own sun does a little jiggle thanks mostly to Jupiter.
2. Dimness -- what they did for this object. Watch a star for dimming as something passes in front of it, although you have to be careful of other causes of temporary decreases in luminescence (like sunspots).
In both cases, it really needs repeated observations over time to establish that it's an orbital event and not something random. In the good ol' days of exoplanet discovery when the equipment wasn't so hot & we expected to find planets pretty much like ours, it took a whole lot of observations before anyone was willing to take the risk of announcing a discovery. Now, with better equipment making it easier to detect hiccups in a star's routine and a more open attitude about how planets behave, discoveries are being announced a lot earlier in the observation process.
To be fair, TFA does give itself a whole lot of wiggle room in interpreting the data. It just fails to mention that follow-up observations aren't confirming the orbital parameters of the assumed planet.
This was followed up on the astro mailing lists as faulty data -- the observers mistook sunspot-dimming for a planet passing in front of the star. The correction hasn't made it to journalists yet and the science article is still in draft, so no link-to-reference, sorry! Planetary formation theory is fragmented and deeply in need of reworking (anyone want a phd topic?), but not to incorporate Jupiters in Mercury-orbits (yet).
I've been spending a lot of time hanging out with the evolutionary psychology research group, and they've taught me that the (evolutionary-)point of boobs is to camouflage the menstrual cycle. The basic logic is:
- if a male can tell a female's cycle, he'll spend all his time and energy on impregnating her at her most fertile(and keeping the other males away) but when she's not fertile dump her.
- for most primates, breasts swell during the fertile point in the cycle (as for why that would indicate a good mating partner, check out some other posts)
- to keep a guy around, women need to hide when they're fertile and when they're not so their breasts are swollen all the time (thus, boobs).
Okay, I'm not an evolutionary psychologist myself so I'm probably missing bits & it's not really relevant to the article, but it's tangentially related and I thought it was a neat theory. It does make me wonder if there's other examples (or counter-examples) of hiding fertility cycles and how it relates to mating/group structure.
It also makes me wonder if a version of the theory will pop up in a how-to-keep-your-man book or magazine some day -- "Now girls, make sure he never knows if you're using birth control or if you're on your period, or he'll be evolutionarily driven to cheat on you!"
The Initiative is already being rolled out. I'm at one of the first-round target schools in a department that won CWSEI funding, and have been involved in several of the curriculum-revision committees.
...kinda lame so far, but if you've got good ideas that fit within our ridiculous budget, I promise I'll try 'em out!
CWSEI is focused on undergraduate science education, both for science students and non-science students. The general plans is:
1. Articulate what we want students to learn
2. Figure out what they're actually learning
3. Fix things
4. Share everything that works with other department/schools
Step 1 has been pretty easy for the courses I've been involved with revising, although it can get pretty funny to see different schools of thought battling it out over what matters most (facts? ability to apply in novel situations? general "science" mindset? problem-solving?)
Step 2 is a bit of a nightmare, but is necessary to figure out if you're actually being effective or not (Step 2 & 3 are iterative until satisfactory, then progress to Step 4). How do you effectively test comprehension vs test taking-ability vs fact retention? It's a bit easier to fix the "Did we teach them or did they already know?" by doing before-and-after tests, but that still doesn't eliminate the keeners going out and self-teaching (no bad prof has ever defeated my desire to learn!)
Step 3 is also a challenge -- in big classes (Natural Disasters can have up to 400 students) it's almost impossible to have one-on-one interactions, they're undergrads so presumably parental-involvement isn't key for learning, the TA-hours to do good grading of neat projects is prohibitive, etc. This is where tech solutions come in: if everyone takes immediate multiple-choice quizzes throughout via clickers, or has to talk with their neighbours to decide on an answer, then we've got them interacting/thinking/talking inside class hours.
For Step 4, what works? U Colorado's physics department was where Carl started this idea, so they've got some pretty cool toys that help students practice concepts they heard in lecture even outside of lab sections. As for my department, no solutions yet...