Pre­par­ing for when largest fault rup­tures

Marlborough Express - - FRONT PAGE -

It’s not a mat­ter of if the Hiku­rangi sub­duc­tion zone will go, it’s when – and that’s what Kiwi sci­en­tists are pre­par­ing for.

Sci­en­tists are de­vel­op­ing an emer­gency re­sponse plan to pre­pare for the rup­ture of New Zealand’s largest fault.

Us­ing a cred­i­ble mag­ni­tude 8.9 earth­quake and tsunami sce­nario, five Civil De­fence Emer­gency Man­age­ment (CDEM) groups from across the North Is­land are work­ing to­gether on the plan.

Natasha Goldring, who is lead­ing the pro­ject, said a re­sponse plan was vi­tal in mak­ing sure peo­ple were ready and re­silient for a fu­ture earth­quake and tsunami event.

‘‘The sce­nario we are us­ing to sup­port the de­vel­op­ment of this re­sponse plan is a very re­al­is­tic ex­am­ple of what we could face in our life­time, or that of our chil­dren and grand­chil­dren.’’

Although the pro­ject is be­ing driven by Civil De­fence groups, peo­ple still needed to make sure they un­der­stood the risks they faced and took the nec­es­sary steps to pre­pare them­selves, Goldring said.

‘‘Com­mu­ni­ties are at the cen­tre of all re­sponse plan­ning, and we want this pro­ject to be a col­lab­o­ra­tive ef­fort.

‘‘We are all re­spon­si­ble for our­selves and our fam­i­lies – we are all part of Civil De­fence in New Zealand.’’

The pro­ject’s launch is in re­sponse to re­search over the past few years which sug­gests the like­li­hood of a rup­ture may be higher than ini­tially un­der­stood.

GNS sci­en­tist Dr Laura Wal­lace said this came down to a com­bi­na­tion of fac­tors in­clud­ing new in­sights from the Kaiko¯ ura earthquakes; ev­i­dence of pres­sure build­ing on the fault; and ge­o­log­i­cal ev­i­dence of pre­his­toric earthquakes on the sub­duc­tion zone.

‘‘A sub­duc­tion zone is where one tec­tonic plate subducts [dives] un­der­neath an­other – the bound­ary be­tween these two plates forms a large fault,’’ she said.

‘‘This one in par­tic­u­lar runs off­shore from the east of Gis­borne down to the top of the South Is­land and poses a sig­nif­i­cant earth­quake and tsunami risk to the en­tire east coast of New Zealand,’’ Wal­lace said.

Sub­duc­tion zone faults had been re­spon­si­ble for most of the world’s dead­li­est earthquakes and tsunamis to date, with Ja­pan 2011 be­ing the most re­cent ex­am­ple, she said.

‘‘We know the Hiku­rangi sub­duc­tion zone can pro­duce large earthquakes and tsunamis, and these events have hap­pened in the past.

‘‘While we’re car­ry­ing out more re­search to build a clearer pic­ture of the haz­ard posed by the Hiku­rangi fault, we know a rup­ture at some point in the fu­ture is cer­tain.’’

For in­for­ma­tion on how to pre­pare for an earth­quake or tsunami, visit www.hap­pens.nz.

Newspapers in English

Newspapers from New Zealand

© PressReader. All rights reserved.