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

 


NZ - German 3D survey: seabed gas hydrate and methane system

NZ - German 3D survey reveals massive seabed gas hydrate and methane system

A joint New Zealand-German research team has discovered a huge network of frozen methane and methane gas in sediments and in the ocean near New Zealand’s east coast. The 16-strong team is using state-of-the-art 3D and 2D seismic and echosounder technology to map both forms of methane within the ocean and beneath the seafloor.

The area off the North Island’s east coast is known to have very large active landslides, up to 15km long and 100m thick, and the team set out to discover what is causing them to move.

What they discovered was direct evidence of widespread gas in the sediment and ocean, and indications of large areas of methane hydrate, ice-like frozen methane, below the seafloor.

The team has identified 99 gas flares in a 50 km2 area, venting from the seabed in columns up to 250 m high. This is believed to be the densest concentration of seafloor gas vents known in New Zealand. 3D seismic data show that landslides and faults allow the gas built up in the sediment to be released into the ocean.

This discovery reveals a hydrate and gas field very different from others known in New Zealand.

“Previously all gas venting sites have been in deeper water and associated with large earthquake faults” say NIWA marine geologist and voyage leader Dr Joshu Mountjoy.

“What we have found is high density methane flares in very shallow water, as well as gas building up beneath a large landslide and being released along the landslide margins”.

In a recently submitted scientific paper the team proposed that these landslides might be the seafloor equivalent of glaciers, but with frozen methane instead of water ice, or alternatively that pressurized gas is causing them to progressively move downslope. The results from this expedition indicate that both of these are possibilities and provide data to carefully test these hypotheses.

The expedition took the opportunity to deploy the German research institute GEOMAR’s high resolution 3D seismic equipment known as the P-Cable from NIWA’s research vessel Tangaroa.

“This equipment is the best available for imaging fluid systems within the seafloor,” says co-leader Professor Sebastian Krastel of the University of Kiel. “The sediment, rocks and fluids we have mapped here are perfectly suited to this equipment, and the area mapped is one of the biggest ever mapped with the P-Cable seismic system.”

The work forms part of a larger project focused on understanding the dynamic interaction of gas hydrates and slow moving active landslides. Dubbed SCHLIP (Submarine Clathrate Hydrate Landslide Imaging Project), ongoing investigations in the project over the next decade will including drilling into the landslides themselves in 2016.

This first part of the project, SCHLIP-3D, is a collaboration between NIWA, GNS Science and the University of Auckland from New Zealand, GEOMAR and the University of Kiel from Germany, Oregon State University from the USA, and the University of Malta.

“The initial findings are very important” says Dr Mountjoy. “Methane is a very effective greenhouse gas and seabed methane release has the potential to dramatically alter the earth’s climate. As ocean temperatures change the methane hydrate system has the potential to become unstable.”

“In terms of natural hazards, the occurrence of very large slow landslides, rather than catastrophic ones, has major implications for the tsunami generating potential of landslides globally as slow landslides are unlikely to cause tsunami.”

“This type of slow moving submarine landslide is essentially unknown around the world, but it is very likely that they do occur widely and are an important process shaping continental margins”.

The team set off from Wellington on 14 April and finished the voyage on 8 May. The work is funded from New Zealand by MBIE and Germany by DFG.

ENDS

© Scoop Media

 
 
 
 
 
Business Headlines | Sci-Tech Headlines

 

Onetai Station: Overseas Investment Office Puts Ceol & Muir On Notice

The Overseas Investment Office (OIO) has issued a formal warning to Ceol & Muir and its owners, Argentinian brothers Rafael and Federico Grozovsky, for failing to provide complete and accurate information when they applied to buy Onetai Station in 2013. More>>

ALSO:

Tomorrow, The UN: Feds President Takes Reins At World Farming Body

Federated Farmers president Dr William Rolleston has been appointed acting president of the World Farmers’ Organisation (WFO) at a meeting in Geneva overnight. More>>

ALSO:

I Sing The Highway Electric: Charge Net NZ To Connect New Zealand

BMW is turning Middle Earth electric after today announcing a substantial contribution to the charging network Charge Net NZ. This landmark partnership will enable Kiwis to drive their electric vehicles (EVs) right across New Zealand through the installation of a fast charging highway stretching from Kaitaia to Invercargill. More>>

ALSO:

Watch This Space: Mahia Rocket Lab Launch Site Officially Opened

Economic Development Minster Steven Joyce today opened New Zealand’s first orbital launch site, Rocket Lab Launch Complex 1, on the Mahia Peninsula on the North Island’s east coast. More>>

Earlier:

Marketing Rocks!
Ig Nobel Award Winners Assess The Personality Of Rocks

A Massey University marketing lecturer has received the 2016 Ig Nobel Prize for economics for a research project that asked university students to describe the “brand personalities” of three rocks. More>>

ALSO:

Nurofen Promotion: Reckitt Benckiser To Plead Guilty To Misleading Ads

Reckitt Benckiser (New Zealand) intends to plead guilty to charges of misleading consumers over the way it promoted a range of Nurofen products, the Commerce Commission says. More>>

ALSO:

Get More From Scoop

 
 
 
 
 
 
 
 
 
Sci-Tech
Search Scoop  
 
 
Powered by Vodafone
NZ independent news