THE HI­MALAYAS

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ex­pected to have such an earth­quake, he said, but “just be­cause you un­der­stand a lot about the ge­ol­ogy and the set­ting and the like­li­ness and the lo­ca­tion, we are much less sure about when things will hap­pen.”

Try­ing to get close to ac­tu­ally pre­dict­ing the tim­ing, he said, is “where the paths of un­der­stand­ing are re­ally im­por­tant to re­al­ize. Ge­ol­ogy does not give us the time de­tail we as hu­man so­ci­ety are look­ing for.” The Earth’s crust is not run­ning on the hu­man clock; it’s run­ning on the ge­o­logic clock. “Peo­ple think 100 years is a stag­ger­ing amount of years, but it’s an ab­so­lute triv­ial amount of years in the ge­o­logic con­text,” he said.

Pre­dict­ing earth­quakes, ac­cord­ing to Robert J. Geller, pro­fes­sor of earth and plan­e­tary science at the Uni­ver­sity of Tokyo’s Grad­u­ate School of Science, “seems to be the alchemy of our times”.

Sci­en­tists are work­ing on “seis­mic weather re­ports”, as one ob­server put it, which are more a math­e­mat­i­cal up­date in shifts in prob­a­bil­ity than any kind of read­ing.

“There is no ma­chine we can put down there and then say when an earth­quake is go­ing to hap­pen,” van der Pluijm said.

At var­i­ous venues and lab­o­ra­to­ries, sci­en­tists have tried to use changes in radon gas emis­sions from the ground as an in­di­ca­tor or looked for epi­demic-like pat­terns in seis­mic ac­tiv­ity to pre­dict the spread of af­ter­shocks as if it were a plague. Es­ti­mates count any­where from 400 to 5,000 mod­els for pre­dict­ing earth­quakes be­ing tested and ex­plored world­wide.

“It’s very hard to do a con­clu­sive test,” said Pro­fes­sor Norm Sleep, a geo­physi­cist at Stan­ford Uni­ver­sity. “If I was em­pir­i­cally pre­dict­ing weather, I could get a lot of ex­pe­ri­ence in a year. In Nepal, it oc­curs ev­ery 75 years. So to get a lot of ex­pe­ri­ence on this is go­ing to take a good while to do bet­ter than just say what the bus driver can tell you.” Use­ful pre­dic­tion

For a pre­dic­tion to be use­ful, Sleep said, it has to be in a rel­a­tively short time and has to spec­ify the mag­ni­tude and lo­ca­tion. “A pre­dic­tion that there’s go­ing to be a mag­ni­tude-8 earth­quake this year some­where in the world is prob­a­bly true, but not par­tic­u­larly use­ful,” he said. “Every­body in the world can’t camp out­side for a year.”

“Ba­si­cally every­body’s equally good at pre­dict­ing earth­quakes, which means that no­body’s good at it at all,” he said.

Sleep said prog­nos­ti­ca­tors could do con­sid­er­ably bet­ter than chance and still not be of any ser­vice. “If you said the chance that one com­ing in 2015 rather than be­ing one in 75 was one in 30 of get­ting this earth­quake in Nepal, you’ve dou­bled the risk but you haven’t re­ally changed how peo­ple re­act to it.”

The vast in­ter­face of In­dia and Asia is what sci­en­tists call a “belt” of seis­mic ac­tiv­ity. Ev­ery­where along it In­dia is try­ing to work its way un­der China. So ev­ery­where along it, earth­quakes are in­evitable.

“If there hasn’t been one in quite a while we can ex­pect that to be the place where the next earth­quake hap­pens,” said van der Pluijm. “It’s called the ‘seis­mic gap the­ory’. When there has not been an earth­quake in a cer­tain place while we know that the process that gen­er­ates earth­quakes is tak­ing place, we can say that is a more likely place for the next event to take place.”

Large earth­quakes in sim­i­lar ar­eas over the past decades are also a dead give­away. But nearby earth­quakes can also throw off a pre­dic­tion. In the case of Nepal, Sleep said, “you go back in the record and they’re oc­cur­ring on av­er­age ev­ery 75 years but not pre­cisely ev­ery 75 years. A large earth­quake nearby Nepal might change the re­cur­rence in­ter­val be­cause we’ve changed the stresses of the Earth.”

And nearby earth­quakes can also add stress to the one in fo­cus, hur­ry­ing the event along. “A small earth­quake doesn’t re­lieve the stresses a lot but it can be a fore­shock, where it’s adding stresses very nearby the earth­quake,” Sleep said. “A mag­ni­tude 5 re­leases about a 30th of the en­ergy of a mag­ni­tude 6, and so on. So this earth­quake re­leased over 20 times more en­ergy than the earth­quake did in Haiti.”

How can that amount of en­ergy be de­scribed in non-earth­quake terms? “Peo­ple have used H bombs, but it’s so large that noth­ing is par­tic­u­larly help­ful,” Sleep said. “This earth­quake was about the size of the 1906 San Fran­cisco earth­quake, but the en­ergy re­leased there was spread over a larger dis­tance. Again both earth­quakes were not par­tic­u­larly good for struc­tures.”

James Jack­son, a Uni­ver­sity of Cam­bridge-based seis­mol­o­gist who was among the sci­en­tists in Kathmandu the week be­fore the earth­quake, told The As­so­ci­ated Press, “The con­struc­tion is ap­palling in Kathmandu.” But he ac­knowl­edged that it made sense in a coun­try where nearly a quar­ter of all peo­ple live be­low the poverty line and build what they can with what they have. Other pri­or­i­ties

“If you live in Kathmandu Val­ley you have other pri­or­i­ties, daily threats and daily nasty things hap­pen to you in terms of air qual­ity, wa­ter qual­ity, pol­lu­tion, traf­fic and just poverty,” he said. “But it doesn’t mean the earth­quakes go away.”

Ma­sonry build­ings that are not re­in­forced are highly vul­ner­a­ble to col­lapse in earth­quakes and when they do col­lapse, they kill a lot of peo­ple, Sleep said. “It’s dif­fi­cult enough in the US to get peo­ple to re­fit build­ings and in an area that’s im­pov­er­ished it is even more dif­fi­cult,” he said. “I’m not an en­gi­neer, but I do know how not to build a build­ing.”

In a book en­ti­tled Earth­quake Haz­ard, Risk, and Dis­as­ters mem­bers from the Na­tional So­ci­ety for Earth­quake Tech­nol­ogy noted Nepal’s lax build­ing codes had only in­creased the de­struc­tion that might be caused by an earth­quake. They wrote:

“No sys­tem ex­ists for con­trol­ling the pro­fes­sional stan­dards of en­gi­neers/de­sign­ers through ref­er­ence to pro­fes­sional qual­i­fi­ca­tions/membership, peer re­view pro­cesses, or by legal means. Fur­ther, the owner builders, who fol­low the ad­vice of lo­cal crafts­men and ma­son lead­ers, build a sig­nif­i­cant pro­por­tion of the build­ings in Nepal.

Nei­ther the owner builder nor the crafts per­sons are aware of the pos­si­ble dis­as­trous con­se­quences of an im­mi­nent earth­quake. They do not have ad­e­quate ac­cess to in­for­ma­tion re­lated to safer build­ing prac­tices and in­cor­po­ra­tion of sim­ple earth­quake-re­sist­ing fea­tures at nom­i­nal ex­tra costs.

Even build­ing con­struc­tion projects funded by na­tional and mul­ti­lat­eral agen­cies gen­er­ally do not spell out ad­e­quate re­quire­ments re­lated to seis­mic safety in their terms of ref­er­ence to their con­sul­tants.”

Van der Pluijm thinks peo­ple should be aware that pre­dict­ing earth­quakes is a two-sided coin: “Even though we can’t give the ex­act date and time, we can tell you the things to ex­pect, and land­slides is one of the things that were pre­dicted once we had an earth­quake for that area. And of course the tragedy is the land­slides are mak­ing it very dif­fi­cult to have res­cue ef­forts

The Hi­malayan moun­tain range dramatically demon­strates one of the most vis­i­ble and spec­tac­u­lar con­se­quences of plate tec­ton­ics.

When two con­ti­nents meet head-on, nei­ther is sub­ducted be­cause the con­ti­nen­tal rocks are rel­a­tively light and, like two col­lid­ing ice­bergs, re­sist down­ward mo­tion. In­stead, the crust tends to buckle and be pushed up­ward or side­ways.

The col­li­sion of In­dia into Asia 50 mil­lion years ago caused the In­dian and Eurasian Plates to crum­ple up along the col­li­sion zone. Af­ter the col­li­sion, the slow con­tin­u­ous con­ver­gence of th­ese two plates over un­der­way.”

The same is true with build­ings, he said. He used the anal­ogy of putting a build­ing on top of a skate­board and then kick­ing the skate­board sud­denly. If the build­ing is not well built, it top­ples over.

“That’s what hap­pens with th­ese build­ings,” he said. “There’s a lot of ag­gres­sive, quick mo­tion of the ground and build­ings when they’re not en­gi­neered to with­stand ground mo­tion have no chance. And peo­ple live in build­ings and this is why the in­juries hap­pen.”

Sleep noted that in the Haiti earth­quake, the US and Canadian em­bassies, which were built to earth­quake code, went vir­tu­ally un­scathed. Haiti, like Nepal, is ba­si­cally de­nuded of wood so there isn’t the ma­te­rial to build wood-frame and plas­ter struc­tures that cause fewer in­juries when they’re shaken into col­lapse.

“It’s not a prob­lem of ig­no­rance, it’s a prob­lem of re­sources,” Su­san Hough of the United States Ge­o­log­i­cal So­ci­ety said. “Peo­ple are build­ing houses to live in with the re­sources that they have. They can’t af­ford re­bar and en­gi­neer­ing.”

Sleep said that earth­quake codes do a lot of good. “There’s no such thing as some­thing be­ing to­tally earth­quake proof, but lev­els of shak­ing in­crease very rapidly as you go to stronger and stronger shak­ing, so any im­prove­ment you make buys you a lot of good,” he said.

Van der Pluijm said that the is­sue re­ally is hu­mans in­ter­act­ing with ge­ol­ogy. “We have to come to grips as a so­ci­ety on how to re­spond to the im­pact of th­ese events. We pre­dict for you what will hap­pen, we can tell you the ground mo­tions, we can tell you what build­ings to build. They’re very ex­pen­sive, of course and th­ese are very poor coun­tries,” he said. mil­lions of years pushed up the Hi­malayas and the Ti­betan Plateau to their present heights.

Most of this growth oc­curred dur­ing the past 10 mil­lion years. The Hi­malayas, tow­er­ing as high as 8,854 m above sea level, form the high­est con­ti­nen­tal moun­tains in the world.

More­over, the neigh­bor­ing Ti­betan Plateau, at an av­er­age el­e­va­tion of about 4,600 m, is higher than all the peaks in the Alps ex­cept for Mont Blanc and Monte Rosa, and is well above the sum­mits of most moun­tains in the United States.

Source: US Ge­o­log­i­cal Sur­vey

“It sounds very preachy to say this be­cause I re­al­ize th­ese peo­ple have daily suf­fer­ing that ex­ceeds ours even on a regular ba­sis,” he con­tin­ued. “That is the scary part: th­ese build­ings have no chance. They are not built to with­stand any­thing. That is why prob­a­bly un­for­tu­nately we’ll hear about a lot more death and suf­fer­ing as the days go by and they dis­cover more vil­lages that were im­pacted and de­stroyed by this process.”

“Th­ese are in­cred­i­bly dam­ag­ing events, th­ese earth­quakes. They are huge events.”

Con­ti­nents on the move are now tracked by GPS and their longer paths can be mea­sured by an­a­lyz­ing the mag­netic anom­alies at the ridge edges, get­ting spread­ing rates and then lay­ing it over the ge­om­e­try of a sphere. The Nepal event moved the Hi­malayas about 2 me­ters higher, but ero­sion and land­slides are al­ready work­ing to re­claim that gain in height.

The rea­son the Hi­malayas are there is ex­actly be­cause of earth­quakes like this,’’ said van der Pluijm. “And there will be more com­ing.’’

Through teleme­try, all of the data is fed in real time into data bases in lab­o­ra­to­ries all over the world and will be an­a­lyzed. “It’s no longer the days when you had to write to monas­ter­ies and they’d send you seis­mo­graph read­ings over a sev­eral-year pe­riod,” Sleep said.

This event will be added to the data base and be “just one more thing out of many,” Sleep said, “and we’re not go­ing to able to pre­dict earth­quakes on what they learned from this one, un­less some­one gets aw­ful more lucky than I think they will.” Con­tact the writer at chris­davis@ chinadailyusa.com

AFP PHOTO / PRAKASH MATHEMA

Peo­ple clear rub­ble in Kathmandu’s Dur­bar Square,

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