August 28, 2015

QotD: The unusually lucky 20th century, meteorologically speaking

Filed under: Environment, History, Quotations, Technology — Tags: , , — Nicholas @ 01:00

… I read a lot of history and thus know a fair bit about how weather impact has been perceived by humans over time. It is a fact that the 20th century was an abnormally lucky hundred years, meteorologically speaking. The facts I managed to jam into tweets included (a) the superstorm that flooded 300 square miles of the Central Valley in California in the 1860s, (b) rainfall levels we’d consider drought conditions were normal in the U.S. Midwest before about 1905, and (c) storms of a violence we’d find hard to believe were commonly reported in the 1800s. I had specifically in mind something I learned from the book Wicked River: The Mississippi When It Last Ran Wild, which relays eyewitness accounts of thunderstorms so intense that travelers had to steeple their hands over their noses in order to breathe air instead of water; but a sense that storms of really theatrical violence were once common comes through in many other histories.

We had a quiet century geophysically as well — no earthquakes even nearly as bad as the New Madrid event of 1812, which broke windows as far north as Montreal. And no solar storms to compare with the Carrington Event of 1859, which seriously damaged the then-nascent telegraph infrastructure and if it recurred today would knock out power and telecomms so badly that we’d be years recovering and casualties would number in the hundreds of thousands, possibly the millions.

(I’m concentrating on 19th-century reports because those tended to be well-documented, but earlier records tell us it was the 20th century calm that was unusual, not the 19th-century violence.)

The awkward truth is that there are very large forces in play in the biosphere, and when they wander out of the ranges we’re adapted to, we suffer and die a lot and there really isn’t a great deal we can do about it; we don’t operate at the required energy scales. For that matter, I can think of several astronomical catastrophes that could be lurking just outside our light-cone only to wipe out all multicellular life on Earth next week. Reality is like that.

Eric S. Raymond, “Heavy weather and bad juju”, Armed and Dangerous, 2011-02-03.

August 7, 2015

Looking back at April’s 7.8 earthquake in Nepal

Filed under: Asia, Science, Technology — Tags: , — Nicholas @ 04:00

At Ars Technica, Scott K. Johnson what has been learned about the devastating earthquake that struck Nepal earlier this year:

The mighty Himalayas have been driven up into the sky by the collision of Eurasia and India, which has migrated north like a tectonic rocket over the last 100 million years. The Indian plate is being crammed beneath the crumpled Himalayan rocks along a dangerous fault that ramps downward to the north.

Lots of GPS sensors and seismometers have been deployed in the area to help seismologists study earthquakes here. Combined with precise satellite measurements of surface elevation changes, researchers have the means to work out where the movement on the fault must have occurred.

The earthquake began about 80 kilometers northwest of Kathmandu and about 15 kilometers beneath the surface. Geologists like to talk about faults “unzipping,” which is a helpful way to visualize what’s going on. A small patch of the fault plane slips, and then expands outward along the fault. In this case, the patch unzipped about 140 kilometers to the east in under a minute, traveling horizontally along the fault plane. Within that patch, the rocks slipped as much as six meters past each other.

Although it’s the seismic energy released by that sudden motion that causes the damage, the surface changes are still eye-catching — some of the GPS stations ended up two meters south of where they had been before the earthquake.

As for that seismic shaking, the pattern of building damage in Kathmandu was partly the result of the geology beneath the city. It sits on a roughly 500-meter-thick stack of lake and river sediment filling a bedrock bowl. The reverberation of seismic waves in that bowl produced a resonance, building stronger waves with a period of 4 to 5 seconds. While fewer homes were actually damaged than expected, taller buildings — which can sway at about that same frequency — didn’t fare as well. (A similar thing happened in the 1985 Mexico City earthquake, when buildings between 6 and 15 stories bore the brunt.)

May 11, 2015

Nepal’s tragic unpreparedness for disaster

Filed under: Asia, Government — Tags: , , , , — Nicholas @ 04:00

In The Walrus, Manjushree Thapa explains why Nepal was so badly prepared for the earthquake:

Following the April 25 earthquake, Nepalis have had to learn the value of preparedness in the most painful way possible. In the aftermath, Pushpa Acharya, a Nepali friend at the University of Toronto, observed, “Knowledge was not our problem.” Indeed. We all knew that our country sits on an active fault line, where the subcontinent collided with the Eurasian plate with such force it created the Himalayas. The last big quake took place in 1934. Others have since struck, but none with the force of 1934’s 8.0 or April 25’s 7.9. We knew that a big earthquake was due.

It was our duty to prepare, and though some of us did so individually, as a society we ignored the warnings. In the past ten days, during search and rescue, and then the beginnings of relief, we’ve had to do some hard thinking about how our country could become more responsible going forward. The root problem may seem obvious: Nepal is one of the poorest countries in the world. Its poverty is, however, a symptom of our history of ill governance, and the reason for our national failure to prepare, which has kept us from becoming a functioning democracy.

When the earthquake struck, the country was in a deep and deeply depressing stupor. The governing parties — a coalition of the Nepali Congress Party and the Unified Marxist Leninists — had reached an impasse with Nepal’s thirty-three opposition parties about what kind of constitution to draft. There was no plan for the country as a whole, let alone in the case of an emergency. The drafting of a constitution has preoccupied, confounded, and eluded Nepal’s polity since 2006, when the Maoists ended a ten-year insurgency to join forces with other parties to remove Gyanendra Bir Bikram Shah. Nepal’s king had used the war as an excuse to end a fragile fifteen-year spell of democracy and install his own military-backed rule. A mass movement restored democracy, and the subsequent peace process promised to restructure the country along just and equitable lines through the drafting of a new constitution

August 17, 2013

Fracking and the environment

Filed under: Environment, Media, Technology — Tags: , , , , — Nicholas @ 09:03

Matt Ridley debunks five common myths about environmental issues with fracking:

The movie Gasland showed a case of entirely natural gas contamination of water and the director knew it, but he still pretended it might have been caused by fracking. Ernest Moniz, the US Energy Secretary, said earlier this month: “I still have not seen any evidence of fracking per se contaminating groundwater.” Tens of thousands of wells drilled, two million fracking operations completed and not a single proven case of groundwater contamination. Not one. It may happen one day, of course, but there’s few industries that can claim a pollution record that good.

Next comes the claim that shale gas production results in more methane release to the atmosphere and hence could be as bad for climate change as coal. (Methane is a more powerful greenhouse gas than carbon dioxide, but stays in the atmosphere for a shorter time and its concentration is not currently rising fast.) This claim originated with a Cornell biology professor with an axe to grind. Study after study has refuted it. As a team from Massachusetts Institute of Technology put it: “It is incorrect to suggest that shale gas-related hydraulic fracturing has substantially altered the overall [greenhouse gas] intensity of natural gas production.”

Third comes the claim that fracking uses too much water. The Guardian carried a report this week implying that a town in Texas is running dry because of the water used for fracking. Yet in Texas 1% of water use is for fracking, in the United States as a whole 0.3% — less than is used by golf courses. If parts of Texas run out of water, blame farming, by far the biggest user.

Fourth, the ever-so-neutral BBC in a background briefing this week described fracking as releasing “hundreds of chemicals” into the rock. Out by an order of magnitude, Auntie. Fracking fluid is 99.51% water and sand. In the remaining 0.49% there are just 13 chemicals, all of which can be found in your kitchen, garage or bathroom: citric acid (lemon juice), hydrochloric acid (swimming pools), glutaraldehyde (disinfectant), guar (ice cream), dimethylformamide (plastics), isopropanol (deodorant), borate (hand soap); ammonium persulphate (hair dye); potassium chloride (intravenous drips), sodium carbonate (detergent), ethylene glycol (de-icer), ammonium bisulphite (cosmetics), petroleum distillate (cosmetics).

As for earthquakes, Durham University’s definitive survey of all induced earthquakes over many decades concluded that “almost all of the resultant seismic activity [from fracking] was on such a small scale that only geoscientists would be able to detect it” and that mining, geothermal activity or reservoir water storage causes more and bigger tremors.


February 26, 2013

UN mistake costs 8,000 Haitian lives, UN refuses to compensate or even apologize

Filed under: Americas, Asia — Tags: , , , , , — Nicholas @ 00:01

A mind-numbing case of bureaucratic error, death, and ass-covering in Haiti:

International affairs can be complicated, but sometimes a case comes along that’s so simple it’s almost absurd. In 2010, the United Nations made a horrendous mistake that, so far, has claimed more than 8,000 lives. Its officials tried to cover it up. When the evidence came out anyway, lawyers for victims’ families petitioned the U.N. to end the crisis, pay damages, and apologize. For a year and a half, the world’s leading humanitarian organization said nothing. Then, last week, it threw out the case, saying, “The claims are not receivable.”

The background should be well-known by now. But despite the fact that American taxpayers have footed the lion’s share of the bill for the U.N. peacekeepers responsible for this disaster — to the tune of roughly $1.5 billion since 2004 — the story remains largely unknown in the United States.

The place was Haiti. The mistake: a killer combination of cholera and gross negligence. The peacekeeping mission, known by its French initials, MINUSTAH, had been in country since 2004, when it was authorized to protect an interim government installed after a coup. Six years later — thanks to a healthy dose of mission creep — the peacekeepers were still there. While rotating troops into what was now post-quake Haiti, the U.N. neglected to adequately screen a contingent of soldiers coming from an active cholera outbreak in Nepal. Upon arrival, the soldiers were sent to a rural U.N. base, outside the quake zone and long known for leaking sewage into a major river system that millions of Haitians used to drink, bathe, wash, and farm. Within days of their arrival, people downstream began to die. The epidemic then exploded, sickening more than 647,000 people, and killing in its first year more than twice the number of people who died on 9/11.

March 20, 2012

New Zealand facing “Marmageddon”

Filed under: Australia, Health, Pacific, Randomness — Tags: , , — Nicholas @ 09:18

Oh, the Marmanity!

An announcement by New Zealand’s leading manufacturer of the black sandwich spread, Marmite, has sparked “marmageddon” fears among Kiwis.

Food company Sanitarium said on its website that supplies “are starting to run out nationwide” after “our Christchurch factory was closed due to earthquake damage”.

Even Prime Minister John Key said he is rationing his personal supply.

[. . .]

“Supplies are starting to run out nationwide, and across the ditch in Australia. We know that we will be off shelf for sometime but we are doing everything we can to minimise how long,” the company said.

“Don’t freak. We will be back soon!”

Of course, the announcement set off a buying-and-hoarding frenzy, making the situation all the more dire. But not to worry: supply and demand has already set in — prices are rising to help even out the distribution of the remaining stocks.

March 9, 2012

Rob Lyons on the lessons of Fukushima

Filed under: Environment, Japan, Media, Technology — Tags: , , — Nicholas @ 09:56

It’s almost exactly a year since the earthquake and tsunami that devastated Fukushima, and Rob Lyons summarizes the lessons we’ve learned from that disaster:

Sunday marks the first anniversary of the earthquake and tsunami that devastated the east coast of Japan on 11 March 2011. The quake, measuring 9.0 on the Richter scale, was the biggest ever to hit Japan and one of the biggest anywhere in the world in the past century. The resulting tsunami caused roughly 20,000 deaths. Yet, shockingly, the biggest issue about the disaster remains the resulting inundation of a nuclear-power plant at Fukushima, which so far appears to have caused precisely zero deaths from leaking radioactivity.

There are many valuable lessons to be learned from this tragedy. One is the importance of development. The earthquake and tsunami that affected the Indian Ocean on Boxing Day 2004 were only marginally larger, yet killed well over 200,000 people. Direct damage from the Japan earthquake was relatively small thanks to high building standards. Warnings allowed many people to escape the unprecedented seawater surge that followed, though video of the wall of water hitting coastal towns is still shocking. Even so, the world’s third largest economy will take a long time to recover fully from what happened. Thankfully, Japan has the resources to do that.

This, however, is not the main lesson being drawn from events a year ago. Around the world, the conclusion many commentators and politicians have drawn is that nuclear power is inherently dangerous and that we need to stop all future nuclear development. This is a perverse conclusion, absolutely flying in the face of the facts. The reaction against nuclear power post-Fukushima reveals much about the navel-gazing, risk-averse worldview that has such a paralysing effect on life in the developed world today.

December 28, 2011

Going beyond merely precut lumber for homebuilding

Filed under: Japan, Technology, Woodworking — Tags: , , , — Nicholas @ 10:52

Precut – Modern Japanese Timber Construction from BAKOKO on Vimeo.

H/T to Popular Woodworking for the link.

July 6, 2011

The fine distinction between actual disaster relief and mere tokenism

Filed under: Environment, Japan, Randomness — Tags: , — Nicholas @ 07:26

In the aftermath of the earthquake and tsunami that hit the coast of Japan, many nations offered assistance and supplies to help the battered area. Some of these offers were both timely and appropriate. Others, however. . .

Stranger still was the arrival on May 11th, a full two months after the earthquake and tsunami, of Sri Lanka’s Disaster Relief Team. Some 15 officials from Colombo’s Ministry of Disaster Management came to help clear debris, via a local NGO called Peace Boat. An extremely decent gesture, likewise. But the flights to and from Japan must have cost the ministry a fortune, relatively. This follows an equally quixotic donation by the Sri Lankan government of 3m tea bags.

Then there is the matter of blankets. Since the disaster some 17 countries as well as the European Union have offered blankets as part of their emergency relief supplies. In March this made sense. Some 25,000 blankets from India, 25,000 from Canada and 30,000 from Thailand were donated within days of the disaster. But did Chile really need to deliver 2,000 blankets on May 31st, by which time the temperatures were balmy to say the least?

Earlier Chile donated 100 kilograms of rice, purchased in Japan, to the city of Minamisanriku. Yet considering the Japanese government stockpiles about one million tonnes of rice in case of a crisis—which it buys under World Trade Organisation commitments, keeps off of the market to support local farmers, and burns after it rots—Chile’s altruism was more likely symbolic than satiating.

In the aftermath of natural disasters, the media usually makes a big, hairy deal if the head of government for the region, state, province, or country isn’t immediately seen touring the area. While it makes for useful video footage for the TV news shows, it’s often counter-productive for the people whose lives have been overturned by the disaster. Heads of state, in particular, don’t just jump in a taxi and head off — there’s a huge entourage that have to precede and accompany the leader. This takes up cargo space, landing slots, and flight paths that might be more usefully devoted to providing help to the afflicted area.

It may be useful psychologically for the victims and the relief workers to see the prime minister or the governor, or whatever, but between the TV and other media folks, the dignitaries themselves, their security detachments, and the other support staff, it almost certainly delays the disaster-struck area actually recovering.

June 1, 2011

New report from the Obviousness Bureau: TEPCO underestimated earthquake/tsunami risks

Filed under: Bureaucracy, Japan, Technology — Tags: , , , , — Nicholas @ 07:55

Hands up, anyone who didn’t see this coming? Okay, put your hands down board members of TEPCO:

Japan underestimated the risk of a tsunami hitting a nuclear power plant, the UN nuclear energy agency has said.

However, the response to the nuclear crisis that followed the 11 March quake and tsunami was “exemplary”, it said.

The Fukushima Daiichi nuclear plant, which was badly damaged by the tsunami, is still leaking radiation.

Japan’s Prime Minister Naoto Kan is facing a no-confidence vote submitted by three opposition parties over his handling of the crisis.

They say he lacks the ability to lead rebuilding efforts and to end the crisis at the Fukushima plant, public broadcaster NHK reported.

Some politicians from Mr Kan’s governing Democratic Party of Japan (DPJ), including former Prime Minister Yukio Hatoyama, are backing the motion.

If it is passed in a vote expected on Thursday, Mr Kan would be forced to resign or call a snap election.

However, given the thousands of dead and missing from the earthquake and tsunami, the attention paid to Fukushima has been rather disproportional. As someone joked yesterday, radiation from Fukushima has killed fewer people (none) than e.coli tainted food in Germany (16 at last report).

Update: In case I’m being too obscure, the “this” I refer to in the initial paragraph is the with-the-benefit-of-hindsight conclusion that the Fukushima plant was inadequately prepared for the earthquake and subsequent tsunami.

May 21, 2011

President of TEPCO falls on his sword a few months late

Filed under: Environment, Health, Japan, Media, Technology — Tags: , , , , — Nicholas @ 11:04

The president of the Tokyo Electric Power Co. (TEPCO) has resigned:

In a business practice that recalled the ritual seppuku suicides of samurai warriors, the president of Japan’s largest power company resigned Friday to assume responsibility for the world’s worst nuclear disaster since Chernobyl.

At a nationally televised news conference, Masataka Shimizu bowed deeply in an exhibition of remorse and declared, “I am resigning for having shattered public trust about nuclear power and for having caused so many problems and fears for the people.

“I want to take managerial responsibility and bring a symbolic close.”

Whether it’s a hearkening-back to Samurai ethos or not, he should have resigned long ago, as soon as it became clear that the company he headed was doing everything it could to conceal the extent of the actual damage both from the media and from the government.

There is a widespread feeling the government and TEPCO officials did not disclose all they knew during the early days of the crisis and have been less than forthcoming since.

In the first weeks after the earthquake, TEPCO officials received 40,000 complaints a day about the lack of information. Police had to be assigned to guard the company’s offices from anti-nuclear protesters.

This week, TEPCO released documents showing it was dealing with three simultaneous nuclear meltdowns, while reassuring people the fuel rods were safely intact in all the reactors.

“Why did it take two months to get to this point?” demanded a Wednesday editorial in the Nikkei business newspaper.

“Even a rough calculation of conditions inside the reactors would have helped in choosing the best response.”

Public confidence was shaken further when it emerged engineers at Fukushima were so unprepared for the disaster, they had to scavenge flashlights from nearby homes and used car batteries to try to reactivate damaged reactor gauges.

Nobody with an ounce of sense is criticizing the workers at the plant for their reaction to an earthquake that was far in excess of the design for the reactors, or a tsunami that was much higher than anything the designers had foreseen. Shit happens, and it was the daily double of fantastically unlikely natural disasters that struck the plant.

The company, however, deserves more than just a light dusting of shame for the way they appear to have been actively preventing the real state of the plant becoming known to the international nuclear community and the national government. A nuclear disaster is everyone’s business, and there were resources available to TEPCO that they signally failed to draw upon. Saving face is not an acceptable reaction to this kind of catastrophe.

April 2, 2011

Cultural bias and bad reporting

Filed under: Japan, Media — Tags: , , , , , , — Nicholas @ 11:01

Jon sent me this link, which discusses the media coverage of the Fukushima workers:

We hear of Fukushima workers “fleeing” the plant, when what happened is they left for a few hours.

We hear about the appearance of tiny amounts of radioactive iodine in Tokyo tap water — but nothing the next day, when it returns to safe levels.

We hear a thousand commentators mention one measurement that was ten million times normal — but nothing when that turns out to have been a measurement error, made by someone who had little sleep and the weight of the world on his shoulders.

We hear people spinning tales of “worst case scenarios” ten thousand times worse than anything that could plausibly happen — and almost nothing about the fact that the Fukushima reactors endured an earthquake 32 times as forceful as they had been designed for, followed by a tsunami twice as high, and still largely survived.

We hear about “plutonium in the soil” — but not that it’s an amount so tiny that pound for pound, bananas in the grocery store are five thousand times more radioactive.

The London Daily Mail reports that the workers “expect to die,” but not that the worst radiation exposure among all the workers amounts to about as much as 15 CT scans, a dose that not only isn’t fatal, but that has no observable health effects.

A lot of bad reporting seems to come from mere scientific illiteracy.

Not only scientific illiteracy, but willful illiteracy. Combine the need to file a story — the more sensational, the better — with the anti-scientific bias that’s been “baked in” to journalism students for two generations, and this is what you get.

Some of it may be simply that fear sells papers, and a headline that says “Catastrophe imminent” sells more papers than “Catastrophe averted.”

But a lot of it appears to be purposeful — it’s no coincidence that the people spinning the wildest tales of catastrophe have also turned out to be associated with vehemently anti-nuclear think tanks and political pressure groups.

Whether it’s because of ignorance or on purpose, the effect of this misreporting it to keep people afraid.

March 29, 2011

The evolution of news to sensational entertainment is complete

Filed under: Health, Media, Technology — Tags: , , , , , — Nicholas @ 08:27

Andrew Orlowski gives the media a damn good whacking over their deliberate panic-mongering:

Sensationalism has always been part of the popular media — but Fukushima is a telling and troubling sign of how much the media has changed in fifty years: from an era of scientific optimism to one where it inhabits a world of fantasy — creating a real-time Hollywood disaster movie with a moralising, chivvying message.

Not so long ago, the professionals showed all the deferential, forelock-tugging paternalism of the dept of “Keep Calm And Carry On”. That era lasted into the 1960s. Now the driving force is the notion that “We’re all DOOMED — and it’s ALL OUR FAULT” that marks almost every news bulletin. Health and environment correspondents will rarely be found debunking the claims they receive in press releases from lobby groups — the drama of catastrophe is too alluring. Fukushima has been the big one.

The Fukushima situation has yet to cause any measurable radiological health effects, and workers at the site were far less hard hit by the quake, tsunami and related events than just about anyone in the disaster zone, but nonetheless the nuclear story rapidly eclipsed the tens of thousands killed directly by the quake. TV’s reaction to the crisis shows how at odds it is with a more rational audience, those who know something about radiation, its consequences, and the human body’s capacity to absorb it and recover from it. The crisis for the media is that thanks to the internet, we can now all bypass these conduits for superstition and stupidity.

Thousands of people died in the earthquake and tsunami (28,000 at last report), yet the media coverage has been unrelentingly focused on Fukushima (where there have been no radiation-linked deaths so far). Surely things like this are scary enough to get equal coverage:

H/T to wormme for the link.

Update: Brendan O’Neill finds a perfect example of journalism:

In a post on the Channel 4 News website, Jon Snow, newsreader, Twitterer, cyclist and “pinko liberal” (his words), unwittingly captures the narcissism and ignorance that are fuelling Western fears over the Fukushima nuclear plant. Never mind the 20,000 who have died and the 200,000 who have been made homeless as a result of the tsunami — what Snow wants to know is what will become of the “dumping of radioactive material in sea water off Japan”.

“When will it pitch up off Cornwall?,” he asks. “Never? Do we know? Will it cause cancers? Will it kill eventually?” Perhaps he has a holiday home in Cornwall, in which case he might possibly be forgiven for thinking that the burning issue of Japan’s monumental tragedy is what impact it will have in St Ives.

Snow’s attempt to justify his navel-gazing obsession with the troubles at Fukushima (apparently he can’t get it out of his mind) is telling. Media coverage of the damaged nuclear plant has understandably “overwhelmed the continuing awfulness of the consequences of the natural disaster itself”, he says, because the natural disaster is “somehow more determinable than the unseen, unknown quantity of danger residing in the reactors, or outside them, in Fukushima”. In short, the natural disaster is too much of a done deal, a proven fact, whereas something far more tantalising lurks within Fukushima: dark, mysterious dangers, uncertainties, swirling unknowns that could unleash their fury at any moment against the unsuspecting Japanese and even us Brits.

March 19, 2011

Trying to sort out truth from speculation at Fukushima

Filed under: Bureaucracy, Environment, Government, Japan, Technology — Tags: , , , , — Nicholas @ 10:53

The only thing that is certain about the Fukushima situation right now is that both the operating company (Tokyo Electric Power Co. aka TEPCO) and the Japanese government have been ridiculously slow to provide information. They may or may not be actively concealing what they know, but they’re taking far too long to share what they do know with the rest of the world.

Inline update: New Scientist has a timeline of Japanese nuclear cover-ups and accidents. [end update]

wormme is a radiological control technician, so he’s very well informed about the overall picture — in a way non-specialists are not — and he’s had an epiphany about Fukushima:

See the light bulb above my head? Lesson Learned!

My first post on Fukushima is still the most widely read. Alas. I’m a radiological control technician who wasn’t paranoid about a radiological situation. Never good. Never acceptable. So I’ve been “hotwashing” myself ever since.

Where did I go wrong? What was the first cause, the primary mistake? I had to know in order to answer the most important question of all:

How do I never make that mistake again?

I turned a nifty phrase in “incalculable danger”, got generous links . . . then steam began venting and cores melting and hydrogen exploding and fuel pools leaking and spent fuel smoldering, all at once, with my brain sprinting like a hamster on a wheel and making about as much progress.

How did Fukushima have several quiet days after the event and only then have the Hellmouth open?

No lesson learned.

Then a couple of days ago we learned the site went six days without electricity. That monstrous tsunami took out the electrical backups, the backup-backups, and the backup-backup-backups in one fell swoop.

And I thought, ”well, that explains most everything”.

But still, no lesson learned.

It’s only now, right now, the realization: I wrote the post assuming that they had electrical power.

Not even an assumption, really. It wasn’t even a consideration. Of course they had power. They couldn’t possibly not have power.

But they did not have power.

Lesson Learned: the Japanese are different from Americans.

He also has interesting and highly informative posts (earlier than the one quoted above, so perhaps to be read with that in mind) on radiation poisoning, stuff that can cause a meltdown, some crappy radiological terminology, characteristics of radiation(s) and shielding(s), why the spent fuel is a bigger problem than the reactors, nuclear triage, time, distance, and shielding, spent fuel pools, first notes on the “Event Summary” file, and how NOT to wear a respirator.

March 18, 2011

West coast earthquake zones

Filed under: Cancon, Environment, Pacific, USA — Tags: , , , , , — Nicholas @ 09:44

According to an article in The Economist, the well-known San Andreas fault in California is not the most likely to cause an earthquake of the magnitude of last week’s quake in Japan. The most likely source is the Cascadia subduction zone:

wikimedia.org - Cascadia subduction zone The most likely megaquake on the West Coast would be much further north — in fact, 50 miles off the coast between Cape Mendocino in northern California and Vancouver Island in southern British Columbia. This 680-mile strip of seabed is home to the Cascadia subduction zone, where oceanic crust known as the Juan de Fuca plate is forced under the ancient North American plate that forms the continent. For much of its length, the two sides of this huge subduction zone are locked together, accumulating stresses that are capable of triggering megaquakes in excess of magnitude 9.0 when they eventually slip. As such, Cascadia is more than a match for anything off the coast of Japan.

What makes Cascadia such a monster is not just its length, but also the shallowness of the angle with which the encroaching tectonic plate dives under the continental mass. The descending plate has to travel 40 miles down the incline before it softens enough from the Earth’s internal heat to slide without accumulating further frictional stresses. Could the fault unzip from end to end and trigger a megaquake — along with the mother of all tsunamis? You bet. By one account, it has done so at least seven times over the past 3,500 years. Another study suggests there have been around 20 such events over the past 10,000 years. Whatever, the “return time” would seem to be within 200 to 600 years.

And the last time Cascadia let go? Just 311 years ago.

Cascadia subduction zone image from wikimedia.org.

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