Drones to predict volcanic eruptions

Hovering over the volcano, a buzzing drone pauses in front of a laser beam on the crater’s edge, as researchers test whether the devices can measure gases to predict eruptions.

On the Aeolian island of Vulcano, off the coast of Sicily, German researcher Marius Schaab, from the Technical University of Munich (TUM), stands next to a gas sensor mounted on a tripod, waiting for the drone his colleague has just launched to draw closer.

The last eruption of the island’s Grand Crater occurred in the late 19th century but the volcano continues to show intense degassing activity.

Soon, the drone positions itself along the axis of the sensor, which transmits an invisible laser beam that passes through the volcanic gas emissions before being reflected by the drone, and travelling back.

The sensor works by “sending a laser beam through some gas and then onto some reflector that measures the intensity of the driving light”, Schaab said.  Using a laser allows the sensor to avoid the gas plume, the researcher told AFP.

Although drones have been used in monitoring volcanoes for about 15 years, scientists are now looking to develop gas measurement tools that are increasingly accurate and risk-free.

Based on the signals sent back to the sensor, an algorithm calculates a map of gas concentration in the 10 or 15 minutes it takes for the drone to follow a predefined path at a distance of up to 60 metres.

Further around the crater, another team of German scientists from the University of Mainz is using sensors carried on a drone to measure concentrations of chemical substances in the air.