Local Govt | National News Video | Parliament Headlines | Politics Headlines | Search

 


Liquefaction Hazard Low in Taranaki

Liquefaction Hazard Low in Taranaki

Thu 23 May 2013

The possibility of earthquake-caused liquefaction in Taranaki is low, with just a few coastal areas potentially having the type of soil that might liquefy.

However those areas would need to be soil-tested before the potential for liquefaction can be confirmed or discounted.

A report by GNS Science has today (Thursday) been released by the region’s four councils, Powerco and Transpower.

In preparing the report, GNS Science examined existing land data held by South Taranaki, Stratford and New Plymouth district councils and Taranaki Regional Council as well as geological information held by GNS.

The key points in the report are:

• Taranaki’s geology is dominated by materials that are not liquefiable. Potential liquefaction hazards in Taranaki are limited to only a few sites.

• The potential for liquefaction hazards has been identified at Port Taranaki; and at the lower reaches of the Mohakatino, Rapanui, Tongaporutu, Mimi, Urenui, Onaero and Waitara rivers and their tributaries (in New Plymouth District); and the lower reaches of the Waitotara, Whenuakura and Patea rivers and their tributaries (in South Taranaki).

• The hazards are based on long time periods: Earthquakes strong enough to cause liquefaction damage to land (a Modified Mercalli Intensity of 8) are expected, on average, every 150 years at Port Taranaki and between 980 and 1070 years at the river areas.

• If liquefaction does occur, it is expected to be of low impact – nothing like what Christchurch experienced following the 2010 and 2011 quakes.

“This is not to say that a big earthquake would definitely cause liquefaction at these coastal sites,” says TRC Director – Environment Quality Gary Bedford.

“The report says these sites could have the potential to liquefy when the right conditions are present: Soil type, high water table and a very strong earthquake.

“The only way to know if a hazard does exist is to undertake direct soil testing at these sites.”

New Plymouth District Council will carry out more detailed investigations (cone penetrometer tests) at five river-mouth areas that have urban areas or residential buildings to confirm or discount the liquefaction potential. These areas are at Waitara, Onaero, Urenui, Tongaporutu and Mohakatino.

South Taranaki District Council Environmental Group Manager John McKenzie says STDC will add the GNS report to its hazard information that is used at times of development, such as when a building consent is applied for or when a land information memorandum is produced.

“The risk of liquefaction in South Taranaki is low and the areas identified are not subject to development pressure. However we will follow closely the results of the cone penetrometer tests,” says Mr McKenzie.

NPDC Manager Quality Assurance John Sutton says the study shows that if liquefaction ever did occur, it is likely the effect would be minor.

“This report was initiated as a result of Christchurch’s experience after the earthquakes in 2010 and 2011 and the enormous amount of liquefaction that resulted,” he says.

“The good news from this report is that if liquefaction ever occurs in Taranaki it probably wouldn’t be anywhere near Christchurch’s level of liquefaction, even with an earthquake that produces Modified Mercalli Intensity shaking of 8.”

The New Zealand MM – or Modified Mercalli – intensity scale grades the impact of an earthquake on people, which can be more useful as an indicator of the earthquake’s significance to the community than the absolute size of the earthquake itself. More information on the MM intensity scale is available on GeoNet’s website.


Documents

Fact sheet (One page 68KB PDF)

Liquefaction Hazard in the Taranaki Region report (34 pages 8.5MB PDF)


ENDS

© Scoop Media

 
 
 
 
 
Parliament Headlines | Politics Headlines | Regional Headlines

 

PARLIAMENT TODAY:

  • Govt Probed Over Health & Safety
  • Questions and Answers 28-05-15
  • Week in Parliament 22-05-15
  • Saturday Sitting
  • House Rises At Midnight
  • Telco Levy Bill Passes
  • Telco Levy Bill Completes First Reading
  • Social Housing Bill Passes Under Urgency

  • Labour Party: McCully Doesn’t Deny Bribe In Saudi Sheep Scandal

    “In Parliament today I asked Murray McCully directly: Why is he the first Minister in history to back a multi-million dollar facilitation arrangement which in other jurisdictions is called a bribe? says Labour’s Export Growth and Trade spokesperson ... More>>

    ALSO:

    Welfare: Closure Of Relationships Aotearoa

    The Aotearoa New Zealand Association of Social Workers (ANZASW) Chief Executive Lucy Sandford-Reed is concerned about the closure of a national service which provides a wide range of services to rural and urban communities throughout New Zealand. More>>

    ALSO:

    TPPA: University Of Auckland Warns Of Negative TPP Impact

    The University of Auckland May 20, 2015 University of Auckland Warns of Negative TPP Impact With the Trans Pacific Partnership (TPP) negotiation drawing to a close, the University of Auckland has expressed serious concerns about its potential implications. ... More>>

    NZ Flag: Flag Referendum Gets Hit Hard In New Poll

    The latest Campbell Live text poll confirms it is time for the Prime Minister to listen to the public and shelve his flag referendum, says the New Zealand First Leader Rt Hon Winston Peters. More>>

    Gordon Campbell: The Government’s Belated Moves On Property Speculation

    Is it a property tax on capital gains or a capital gains tax on property? The Jesuitical distinctions in the government’s spin about its latest moves on property speculators are all about whether the government can claim that it jumped, or confess that it ... More>>

    Grant Robertson:
    Key Can’t Just Be Prime Minister For Parnell

    John Key must show New Zealanders in next week’s Budget that he is more than the Prime Minister for Parnell, and is also the Prime Minister for Pine Hill, Putararu and Palmerston North, Labour’s Finance spokesperson Grant Robertson says. In a ... More>>


    Labour Party: More Regional Jobs Go In Corrections Reshape

    News that 194 Corrections staff are to lose their jobs will have ramifications not only for them and their families but for the wider community, Labour’s Corrections spokesperson Kelvin Davis says. Prison units at Waikeria, Tongariro and Rimutaka ... More>>

    ALSO:

  • NZ First - Prison Job Losses to Send Money Offshore
  • TPPA: ‘Team Obama’ Regroups On Fast Track, Still Not Deliverable

    ‘After yesterday’s stinging and unexpected defeat for the Obama administration’s attempt to advance Fast Track legislation in the US Senate, Senate leaders have worked up a compromise they think will get them past this blockage’, according to Auckland ... More>>

    NZ Government: 5,500 More Doctors And Nurses In Our Hospitals

    Health Minister Jonathan Coleman says a record number of doctors and nurses are working in District Health Boards across the country. More>>

    Controller and Auditor General: Katherine Rich Conflict of Interest Decision

    We are writing to you about a matter that has been raised with us by members of the public. More>>

    ALSO:

    Budget 2015: Andrew Little On The 2015 Budget

    Speaking to the Chamber of Commerce, the Labour opposition leader attacked the government’s approach to economic issues facing New Zealand. He said they have been “more than reckless in their complacency” and “the next week’s budget will do nothing ... More>>

    Defence Force: NZDF Building Partner Capacity Mission Personnel In Iraq

    NZDF Building Partner Capacity Mission Personnel in Iraq The New Zealand Defence Force Building Partner Capacity training mission contingent is in place at Taji Military Complex in Iraq. The Chief of Defence Force Lieutenant General Tim Keating says the ... More>>

    PM Press Conference: ACC Levy Cuts Announced

    In a press conference this afternoon in Wellington, ACC Minister Nikki Kaye proposed $500 million worth of ACC levy cuts. More>>

    Quakes: New Process For Red Zone Crown Offers

    Canterbury Earthquake Recovery Minister Gerry Brownlee has announced a process to give everyone a say on the Crown offers to owners of vacant, commercial/industrial and uninsured properties in the Residential Red Zone. More>>

    ALSO:

    Get More From Scoop

     

    LATEST HEADLINES

     
     
     
     
     
     
     
     
     
    Regional
    Search Scoop  
     
     
    Powered by Vodafone
    NZ independent news