Video | Business Headlines | Internet | Science | Scientific Ethics | Technology | Search

 


How prepared are we for a major marine earthquake?


How prepared are we for a major marine earthquake?

This week, New Zealand’s leading coastal scientists, engineers and planners are attending the New Zealand Coastal Society 20th Annual Conference in Auckland. At the conference, NIWA’s Dr Philip Barnes will explore the question of how well do we know New Zealand’s submarine earthquake hazards.

Drawing on NIWA’s experience from Canterbury earthquakes, and how this work feeds into a bigger picture of earthquake risk in New Zealand, Dr Barnes says, “We have to be prepared for these sorts of marine earthquakes in many New Zealand locations.”

GNS Science has recently led a major revision of the New Zealand National Seismic Hazard Model (NSHM), and have worked closely with NIWA to capture submarine faulting. The model includes a range of earthquake hazard estimates.

A number of newly-identified active fault sources have recently been incorporated into the NSHM model, increasing the total by around 200, to about 530. The recent increase is largely attributed to the inclusion of the newly-identified offshore fault sources, including previously unknown faults in the bedrock under Pegasus Bay, Canterbury.

A particularly large offshore fault was discovered when NIWA's research vessel Kaharoa conducted a seismic survey of 800 square kilometres in southern Pegasus Bay, shortly after the February 2011 Christchurch earthquake.

In the last decade, there have been many major earthquakes causing severe ground-shaking and tsunamis around the world. The Boxing Day tsunami of 2004 killed more than 200,000 people and resulted in widespread destruction. One of the most powerful earthquakes on record struck the north-east coast of Japan in 2011, triggering massive tsunami waves with up to 40 metres of run-up height.

“There are many earthquake faults on the seafloor around our coasts, and the next major earthquake could be centred offshore. So it highlights the need for coastal marine investigations of active earthquake faulting, for both ground-shaking hazards and tsunamis,” says Dr Barnes.

“NIWA’s geosciences team responded rapidly to the Canterbury earthquakes, working closely with the Natural Hazards Research Platform and other authorities to inform the recovery.”

Some locally significant changes in probabilistic earthquake hazard were observed in some areas when the methodology of the NSHM was revised, and the large number of new active fault sources were included in the model.

“If a major earthquake occurs on a seafloor fault, we might already have information about that fault.

“We also now have some experience in how to respond and learn more about the cause of a major earthquake if such an event occurs. The more background information we have on active faults, the better,” says Dr Barnes.

“We have worked offshore from Fiordland, right through Canterbury, Marlborough, Cook Strait, Kapiti, Hikurangi margin (on the east coast of the North Island), New Plymouth and Bay of Plenty. We’ve identified faults and characterised them, and in some areas we are now working on the history of past earthquakes.”

The New Zealand NSHM project is a collaboration between GNS Science and NIWA, with input from Victoria University of Wellington and the University of Canterbury. The new model informs engineering design and the insurance sector.

“Incorporating the NIWA offshore active fault data into the NSHM is a shining example of our very fruitful GNS-NIWA collaboration” says Mark Stirling, leader of the NSHM project.

The New Zealand Coastal Society Annual Conference – ‘Making Waves, 20 years and beyond’ is being held 14 – 16 November 2012, at the Royal NZ Yacht Squadron in Auckland.
ends

© Scoop Media

 
 
 
 
 
Business Headlines | Sci-Tech Headlines

 

Scoop Business: Alex Swney Pleads Guilty To $2.5M Fraud Charge

Alex Swney, former chief executive of the Auckland city centre business association Heart of the City, has pleaded guilty to dishonestly using documents to obtain $2.5 million. More>>

ALSO:

Petrol Burns Prices: Second Consecutive Quarterly Fall For CPI

The consumers price index (CPI) fell 0.3 percent in the March 2015 quarter, following a 0.2 percent fall in the December 2014 quarter, Statistics New Zealand said today. The last time the CPI showed two consecutive quarterly falls was in the December 1998 and March 1999 quarters. More>>

ALSO:

Scoop Business: NZ Broadcasters Launch Battle Against Global Mode ISPs

New Zealand broadcasters have confirmed they’ve launched legal proceedings against internet service providers who give customers’ access to “global mode”, which allows customers access to offshore online content, claiming it breaches the local content providers’ copyright. More>>

ALSO:

Sanford: Closure Of Christchurch Mussel Processing Plant Confirmed

The decision comes after a period of consultation with the 232 staff employed at the Riccarton site, who were told on 9 April that Sanford was considering the future of mussel processing in Christchurch. Recent weather patterns had impacted on natural spat (offspring) supply... More>>

ALSO:

Price Of Cheese: Dairy Product Prices Fall To The Lowest This Year

Dairy product prices fell in the latest GlobalDairyTrade auction, hitting the lowest level in the 2015 auctions so far, as prices for milk powder and butter slid amid concern about the outlook for commodities. More>>

ALSO:

Houston, We Have An Air Route: Air New Zealand To Fly Direct To The Heart Of Texas

Air New Zealand will fly its completely refitted Boeing 777-200 aircraft between Auckland and Houston up to five times a week opening up the state of Texas as well as popular nearby tourist states such as Louisiana and Florida. More>>

ALSO:

Scoop Business: Reserve Bank’s Spencer Calls On Govt To Rethink Housing Tax

The Reserve Bank has urged the government to take another look at a capital gains tax on investment in housing, allow increased high-density development and cut red tape for planning consents to address an over-heated Auckland property market. More>>

ALSO:

Get More From Scoop

 
 
 
 
 
 
 
 
 
Sci-Tech
Search Scoop  
 
 
Powered by Vodafone
NZ independent news