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

 


Scientists To Probe Lake Rotomahana

MEDIA RELEASE from GNS Science, 15 NOVEMBER 2010

Scientists To Probe Lake Rotomahana’s Geothermal Vents

Scientists from the New Zealand and the United States are planning to use two torpedo-like unmanned underwater vehicles to map the
bottom of Lake Rotomahana, near Rotorua, and look for hydrothermal activity on the lake bed.

The project, scheduled to start in late January, will be the first time in New Zealand that a lake bed has been mapped by autonomous
underwater vehicles, or AUVs.

As well as producing a detailed three-dimensional map of the lake bed, the sophisticated sensors on the AUVs will enable the scientists
to locate hydrothermal vents at the bottom of the lake.

The present-day chemistry of the lake indicates that geothermal fluids are pouring into it from below Scientists are keen to find out the
number of vents on the lake bed, their locations, and the intensity of venting.

The project is a collaboration involving GNS Science, the Woods Hole Oceanographic Institute (WHOI) in the US, the University of Waikato,
and the Te Arawa Lakes Trust Board.

Lake Rotomahana, roughly 3km by 6km in size, enlarged in size after the eruption of Mt Tarawera in 1886, which is thought to have
destroyed and drowned the famed Pink and White Terraces. The Terraces, or their remnants, are believed to be buried at the bottom
of the lake.

The battery-powered AUVs will motor through the lake at about walking pace on a pre-programmed grid pattern to produce a highly
accurate three-dimensional view of the lake bed.

Other measurements they will take include temperature, pH, conductivity, depth, optical clarity of the water, and the electrical potential, or Eh,
of the lake water. The vehicles will also be able to map the magnetic signature of the volcanic rocks beneath the lake floor and are equipped
with side-scan sonar, which helps to distinguish different rock types.

Scientists will compile the data into a layered map of the lake bed which will elucidate the nature of the geology and hydrothermal
activity at Rotomahana.

Project leader, Cornel de Ronde of GNS Science, said there were very few examples of hydrothermal activity in freshwater lakes in the world,
and even fewer had been studied in detail.

“Our aim is to determine what happened to the Pink and White Terraces hydrothermal system when it was drowned in the enlarged
Lake Rotamahana soon after the 1886 eruption,” Dr de Ronde said.

“We also want to know what links there are between the drowned geothermal systems of Lake Rotomahana and the adjacent geothermal
system at Waimangu.

“This is a rare opportunity to document the death of a land-based geothermal system and its rebirth at the bottom of a lake.”

The accuracy of the mapping will enable the scientists to see features on the lake bed about the size of a suitcase.

When vents are located and given a GPS coordinate, scientists will lower instruments from a boat to determine temperature, flow rate,
and chemical composition of the vent fluids. This will help build a computer model of the hydrothermal and magma systems beneath the lake.

Prior to 1886, the Pink and White Terraces were considered an international marvel and were sometimes referred to the eighth natural
wonder of the world. They were the largest silica terraces in the world and represented an enormous outflow of geothermal fluid.

Scientists believe the Terraces, or their remnants, are today covered by at least 50m of lake water plus an additional unknown thickness
of sediment. Lake Rotomahana is 115m deep at its deepest point.

GNS Science, with the support of the Royal Society, will be offering activities to Rotorua primary and intermediate schools in connection
with this project. Information on the activities will be sent teachers in the Rotorua area this week.

END

© 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