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

 


Quake unravelling continues

Quake unravelling continues


Though the aftershocks from last week's Kaikoura earthquake have been quieter this week (knock on wood), science behind the quake continues apace.

Niwa's research vessel Tangaroa was diverted to the Kaikoura coast after last week's earthquake. Surveys of the seabed have confirmed the Needles Fault ruptured 34km offshore. Scientists on board the vessel have collected 61 sediment cores - each measuring about 5.5 metres - from the continental margin between Poverty Bay and Kaikoura (pictured).

It's hoped the cores will provide evidence of submarine landslides. Niwa marine geologist Dr Philip Barnes said the cores revealed a huge turbidity current offshore from Marlborough and Wairarapa - extending at least 300km from Kaikoura. But the locations of underwater landslides that caused the turbidity have not been identified.

Meanwhile back on land, geologists have been looking at evidence of new faulting in Marlborough. University of Canterbury researchers found "spectacular" fault displacements, including an area north of Waiau whihc had 2.2m horizontal displacement and 1.5m vertical.

GPS stations detected a slow-slip earthquake underway in the Hawke's Bay and Gisborne regions. Silent or slow-slip earthquakes are undetectable by both humans and GeoNet's seismographs, but the GPS stations detected movement of up to 2-3cm - similar to that seen in previous East Coast slow-slip events. A magnitude 5.5 earthquake that struck the area on Tuesday fit with previous earthquake "clusters" during slow-slip events in the area.

Kayak guides spotted an interesting by-product of the earthquake - bubbles in the sea off Kaikoura. University of Canterbury's Dr Matthew Hughes said the bubbles were likely due to a mix of carbon dioxide and hydrogen sulphide released through cracks in the seafloor caused by the magnitude 7.8 earthquake.

An aftershock that damaged homes in North Canterbury on Tuesday was within the aftershock forecast, GNS Science's Natalie Balfour told media. But since then, things have been particularly quiet.

GeoNet's Sara McBride wrote on Wednesday that the number of aftershocks was within the forecasted range, but on the low side and cautioned people still to be prepared. "Just because we are in the lower end of the forecast, it doesn't mean that this will stay that way."

In non-earthquake news, an air force flight last week reported floating pumice to the west of Minerva Reef - about 600km south-east of Fiji. GeoNet director Dr Ken Gledhill said satellite images showed the pumice rafts extended for more than 100km. Though scientists have not yet tracked the pumice back to a source location, Dr Gledhill said the nearest active submarine volcano - Monowai - was active on November 10-11.

Finally, some numbers. Writing on GeoNet, Dr Gledhill pulled out some of the data from the Kaikoura earthquake:

• Movement along at least five separate faults, extending about 150km up the coast

• Land movements up to 11m horizontally and 5m vertically

• Maximum ground shaking 1.3 times the force of gravity in Ward

• Tsunami height of 4m at Little Pigeon Bay

• More than 5,500 aftershocks.

Quoted: Stuff.co.nz


"We're 12 days out, which in geological terms is not a long time at all."

GNS Science seismologist Dr Matt Gerstenberger
on aftershock probabilities from the Kaikoura earthquake.

ends

© Scoop Media

 
 
 
 
 
Business Headlines | Sci-Tech Headlines

 

Cosmetics & Pollution: Proposal To Ban Microbeads

Cosmetic products containing microbeads will be banned under a proposal announced by the Minister for the Environment today. Marine scientists have been advocating for a ban on the microplastics, which have been found to quickly enter waterways and harm marine life. More>>

ALSO:

NIWA: 2016 New Zealand’s Warmest Year On Record

Annual temperatures were above average (0.51°C to 1.20°C above the annual average) throughout the country, with very few locations observing near average temperatures (within 0.5°C of the annual average) or lower. The year 2016 was the warmest on record for New Zealand, based on NIWA’s seven-station series which begins in 1909. More>>

ALSO:

Farewell 2016: NZ Economy Flies Through 2016's Political Curveballs

Dec. 23 (BusinessDesk) - New Zealand's economy batted away some curly political curveballs of 2016 to end the year on a high note, with its twin planks of a booming construction sector and rampant tourism soon to be joined by a resurgent dairy industry. More>>

ALSO:


NZ Economy: More Growth Than Expected In 3rd Qtr

Dec. 22 (BusinessDesk) - New Zealand's economy grew at a faster pace than expected in the September quarter as a booming construction sector continued to underpin activity, spilling over into related building services, and was bolstered by tourism and transport ... More>>

  • NZ Govt - Solid growth for NZ despite fragile world economy
  • NZ Council of Trade Unions - Government needs to ensure economy raises living standards
  • KiwiRail Goes Deisel: Cans electric trains on partially electrified North Island trunkline

    Dec. 21 (BusinessDesk) – KiwiRail, the state-owned rail and freight operator, said a small fleet of electric trains on New Zealand’s North Island would be phased out over the next two years and replaced with diesel locomotives. More>>

  • KiwiRail - KiwiRail announces fleet decision on North Island line
  • Greens - Ditching electric trains massive step backwards
  • Labour - Bill English turns ‘Think Big’ into ‘Think Backwards’
  • First Union - Train drivers condemn KiwiRail’s return to “dirty diesel”
  • NZ First - KiwiRail Going Backwards for Xmas
  • NIWA: The Year's Top Science Findings

    Since 1972 NIWA has operated a Clean Air Monitoring Station at Baring Head, near Wellington... In June, Baring Head’s carbon dioxide readings officially passed 400 parts per million (ppm), a level last reached more than three million years ago. More>>

    ALSO:

    Get More From Scoop

     
     
     
     
     
     
     
     
    Sci-Tech
    Search Scoop  
     
     
    Powered by Vodafone
    NZ independent news