NZ lake could light up a city

The geothermal heat being produced by a lake in New Zealand is enough to power millions of light bulbs, according to scientists.


Preliminary results from state-of-the-art measuring devices placed on the bed of Lake Rotomahana, near Rotorua, show the geothermal system under the lake has heat energy output about five times higher than similar measurements at hot vents on the sea floor of the Pacific Ocean.


Lake Rotomahana

“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 light bulb every square metre,” said project leader Cornel de Ronde.

The project, led by GNS Science in collaboration with the United States’ Woods Hole Oceanographic Institution and the National Oceanic and Atmospheric Administration and the University of Waikato, is seeking to measure the heat output of the 800-hectare lake.

The instruments to measure the heat, being used in New Zealand and in a lake for the first time, will be placed at 110 grid points on the lake floor for up to 24 hours before moving to a new spot.

The lake is roughly 3km by 6km and is about 120m deep at its deepest point.

Results from the latest expedition will help scientists understand the size and the state of the magma body that lies under the region.