Over 143 mil­lion Amer­i­cans live in quake-prone ar­eas: sci­en­tists

The China Post - - ARTS - BY ALI­CIA CHANG

More than 143 mil­lion peo­ple in the main­land states now live on shaky ground, earth­quake sci­en­tists say. That’s be­cause more peo­ple have moved into the quake­prone West Coast and some quake zones were re­cently ex­panded, ac­cord­ing to re­searchers from the U.S. Ge­o­log­i­cal Sur­vey.

The re­search didn’t in­clude Alaska, Hawaii and Puerto Rico, but sci­en­tists us­ing older data es­ti­mated that nearly half of Amer­i­cans — or 150 mil­lion peo­ple — live in earth­quake re­gions.

About 28 mil­lion peo­ple face the high­est threat, mostly along the West Coast where the San An­drea Fault cuts through Cal­i­for­nia and a huge un­der­sea fault lurks off the Pa­cific North­west.

The lat­est cal­cu­la­tions by the USGS, Fed­eral Emer­gency Man­age­ment Agency and Cal­i­for­nia Ge­o­log­i­cal Sur­vey were re­ported Wed­nes­day at a Seis­mo­log­i­cal So­ci­ety of Amer­ica meet­ing in Pasadena.

There have been a few pre­vi­ous at­tempts to fig­ure out how many peo­ple live in quake-prone ar­eas. A fed­eral es­ti­mate two decades ago found that 75 mil­lion peo­ple in 39 states were at risk of shak­ing.

The USGS last year up­dated its na­tional earth­quake maps that in­creased the quake dan­ger for one-third of the coun­try. While the Pa­cific coast re­mains a seis­mic hotspot, other re­gions as the Rock­ies, Mid­west, New Eng­land and parts of the Southeast also face an el­e­vated risk.

“The dis­tri­bu­tion of earth­quake risk is much broader and wider be­yond the West Coast,” lead re­searcher and USGS con­trac­tor Kishor Jaiswal said in an email.

The new work fo­cused on the Lower 48 states be­cause sci­en­tists don’t yet have up­dated maps for the whole coun­try. Re­searchers didn’t take into ac­count re­gions where small earth­quakes have been caused by oil and gas drilling. If those were in­cluded, the num­ber of peo­ple ex­posed to shak­ing would be higher, Jaiswal said.

The team also cal­cu­lated po­ten­tial eco­nomic losses from dam­aged build­ings such as homes, hos­pi­tals, schools and fire sta­tions. The av­er­age loss amounted to US$4.5 bil­lion with the great­est fi­nan- cial hit to Cal­i­for­nia, Ore­gon and Wash­ing­ton.

“We’ve al­ways been told that we should be pre­pared. But this study puts some teeth into the rec­om­men­da­tion,” said USGS seis­mol­o­gist Sue Hough who had no con­nec­tion to the re­search.

Gov­ern­ment sci­en­tists have been testing a West Coast seis­mic alert sys­tem de­signed to de­tect the ini­tial shock waves from a large jolt, cal­cu­late the strength and give a few sec­onds of warn­ing be­fore the ar­rival of slower, dam­ag­ing waves.

Sup­port­ers say an early warn­ing sys­tem would al­low trains to stop, com­pa­nies to shut off gas lines and peo­ple to duck un­der a ta­ble un­til the shak­ing stops. Only se­lect sci­en­tists and com­pa­nies cur­rently re­ceive the alerts.

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