NEWS RELEASE from GNS Science
3 NOVEMBER 2006
Scientists Install Lahar Measuring Equipment On Ruapehu
Researchers from GNS Science and Massey University’s Volcanic Risk Solutions installed a set of lahar-measuring
equipment on Mount Ruapehu this week.
The gear includes a radar device to measure flow depth and a series of instruments to detect and record the
ground-shaking caused by a lahar as it flows down the mountain.
This will enable scientists to determine the velocity, volume, and sediment load of a lahar, which will indicate its
destructive potential, GNS Science project co-leader Vern Manville said.
“This is a key site as any lahars in the Whangaehu valley should have reached their maximum size and sediment
concentration by this point,” Dr Manville said.
The largest lahars during the 1995 eruptions were up to 80m wide and 6m deep in this area, 7km downstream from Crater
The equipment is the first in a series of planned deployments, which will be made over the summer months, to capture as
much information as possible from any lahar along the expected flow path.
A lahar could be caused by a collapse of the tephra barrier at the Crater Lake, or it could be triggered by a volcanic
eruption. The Whangaehu valley is the main lahar channel on Ruapehu, and has carried more than 45 such flows since
historical records began in the 1860’s.
The solar-powered equipment stores data on a memory loop lasting a week. It is bolted firmly to a lava flow on the
valley wall, high enough to be out of harms way should a lahar occur.
The research is funded by a Royal Society Marsden grant, the Earthquake Commission, and the Foundation for Research
Science and Technology.