Taking the pulse of an active volcano: A drone at work on Whakaari/White Island

Rotorua Daily Post

8 Jul, 2019 08:37 PM2 mins to read

Video by GNS Science.

Volcano monitoring staff have used technology and "simple Kiwi ingenuity" to take the pulse of an active volcano in a unique way.

GNS Science used a drone, or UAV (unmanned aerial vehicle), to collect water samples from Whakaari/White Island's crater lake last month.

Whakaari/White Island is New Zealand's most active volcano, situated 48km off the Bay of Plenty coast, and the most extreme environment where GNS staff work.

GNS Science volcanologist Brad Scott, pictured at White Island. Photo / File

The volcano's crater lake is a witch's brew of bubbling, hot and acidic fluid that is far more acidic than battery acid. It has a lake temperature of around 60-70C with a pH of around -1.0.

GNS Science volcanologist Geoff Kilgour said they collected samples by filling containers manually where they could but conditions on their last visit made it impossible to approach the lake safely.

"So we used a drone to take the sample for us. While we regularly use UAVs for monitoring, this is the first time we used one to collect samples. The steam and wave action in the lake created many challenges for our team, not to mention the pilots had to be positioned 25 metres above the actual lake."

The sampling device itself was simple "Kiwi" ingenuity, thanks to their clever technicians.

"It needed to be light, something that wouldn't react with the water or contaminate the sample, and be easy to see from 150-200m distance. They got to work and using string and a dismembered sample bottle, produced our successful sampling tool."

Kilgour said understanding the chemistry of the crater lake played a crucial role in interpreting the changes occurring on the island.