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

 


Scientists probe Lake Rotomahana's volcanic heat engine

6 March 2014

Scientists probe Lake Rotomahana's volcanic heat engine

The scientists who found remnants of the Pink and White Terraces under Lake Rotomahana two years ago are back at the lake this week measuring its geothermal heat output.

For many years scientists have known there is a large active geothermal system under the lake, and this will be the most sophisticated attempt at measuring the heat output of the 800 hectare lake.

To achieve this they are using state-of-the-art heat measuring devices that are being used in New Zealand for the first time. The instruments sit on the lakebed for up to 24 hours collecting heat measurements before being moved to a new spot.

They are also using a camera to take high-resolution photos of geothermal features on the lake floor and are collecting water samples from the lake floor for analysis.

The project is being led by GNS Science in collaboration with Woods Hole Oceanographic Institution and the National Oceanic and Atmospheric Administration - both from the US - and the University of Waikato. The project also has the support of the Te Arawa Lakes Trust.

The scientists are measuring heat being produced at 110 grid points on the floor of the lake to calculate the heat being produced by the entire lake. This is only the third time the US-developed heat-measuring devices have been used, and the first time they have been deployed in a lake.

Preliminary results from the first batch of measurements have shown a couple of hot spots where heat energy output (watts per square metre) is about five times higher than similar measurements at hot vents on the seafloor of the Pacific.

Results for the entire lake will represent another piece in the puzzle to help scientists understand the size and the state of the magma body that underlies this part of the Bay of Plenty.

"Once we have the information about the lake's heat energy output, we will be able to put together a comprehensive story on the evolution of the volcano-geothermal system since the Tarawera eruption of 1886," said project leader Cornel de Ronde of GNS Science.

"The initial results show the amount of heat passing through the lake floor is truly impressive. There's about two square kilometres of the lake floor where there is enough heat energy to power a 60 watt lightbulb every square metre," Dr de Ronde said.

Te Arawa Lakes Trust Chief Executive Roku Mihinui said the survey had given a clearer picture of what the Tarawera eruption did to Lake Rotomahana and the surrounding landscape where some of the Trust's ancestors had lived.

"It has also given some inkling of the latent power of the geothermal activity under the lake, as well as potential development opportunities and possible risks."

The were was still more to learn and the Trust hoped that the New Zealand and American scientists would continue their research, Mr Mihinui said.

Lake Rotomahana is the warmest of the Rotorua lakes and sits at about 11 to 14 degrees Celsius throughout the year.

The Okataina Volcanic Centre gives rise to a substantial amount of volcanic and geothermal activity east of Rotorua, and was the source of the eruption of Mount Tarawera in June 1886.

Background
The Okataina Volcanic Centre lies east of Rotorua and formed between 250,000 and 50,000 years ago. It has erupted six times in the past 10,000 years, most recently with the eruption of Mount Tarawera in 1886. The time between eruptions from this Centre is long, between 700 and 3000 years. Eruptions from this type of volcanic centre are usually many times larger than those from cone volcanoes such as Ruapehu, Ngauruhoe, and Tongariro.

ENDS

© Scoop Media

 
 
 
 
 
Business Headlines | Sci-Tech Headlines

 

Sky City : Auckland Convention Centre Cost Jumps By A Fifth

SkyCity Entertainment Group, the casino and hotel operator, is in talks with the government on how to fund the increased cost of as much as $130 million to build an international convention centre in downtown Auckland, with further gambling concessions ruled out. The Auckland-based company has increased its estimate to build the centre to between $470 million and $530 million as the construction boom across the country drives up building costs and design changes add to the bill.
More>>

ALSO:

RMTU: Mediation Between Lyttelton Port And Union Fails

The Rail and Maritime Union (RMTU) has opted to continue its overtime ban indefinitely after mediation with the Lyttelton Port of Christchurch (LPC) failed to progress collective bargaining. More>>

Earlier:

Science Policy: Callaghan, NSC Funding Knocked In Submissions

Callaghan Innovation, which was last year allocated a budget of $566 million over four years to dish out research and development grants, and the National Science Challenges attracted criticism in submissions on the government’s draft national statement of science investment, with science funding largely seen as too fragmented. More>>

ALSO:

Scoop Business: Spark, Voda And Telstra To Lay New Trans-Tasman Cable

Spark New Zealand and Vodafone, New Zealand’s two dominant telecommunications providers, in partnership with Australian provider Telstra, will spend US$70 million building a trans-Tasman submarine cable to bolster broadband traffic between the neighbouring countries and the rest of the world. More>>

ALSO:

More:

Statistics: Current Account Deficit Widens

New Zealand's annual current account deficit was $6.1 billion (2.6 percent of GDP) for the year ended September 2014. This compares with a deficit of $5.8 billion (2.5 percent of GDP) for the year ended June 2014. More>>

ALSO:

Still In The Red: NZ Govt Shunts Out Surplus To 2016

The New Zealand government has pushed out its targeted return to surplus for a year as falling dairy prices and a low inflation environment has kept a lid on its rising tax take, but is still dangling a possible tax cut in 2017, the next election year and promising to try and achieve the surplus pledge on which it campaigned for election in September. More>>

ALSO:

Job Insecurity: Time For Jobs That Count In The Meat Industry

“Meat Workers face it all”, says Graham Cooke, Meat Workers Union National Secretary. “Seasonal work, dangerous jobs, casual and zero hours contracts, and increasing pressure on workers to join non-union individual agreements. More>>

ALSO:

Get More From Scoop

 
 
Standards New Zealand

Standards New Zealand
 
 
 
 
 
 
 
 
Sci-Tech
Search Scoop  
 
 
Powered by Vodafone
NZ independent news