Drones are flying straight into volcanoes, for life-saving science
With an estimated 300 active volcanoes on Earth, the challenge is how to monitor them all to send out early warnings before they erupt. Measuring volcanic gas emissions is also no easy task.
Now researchers have designed specially-adapted drones to help gather data from an active volcano in Papua New Guinea (PNG).
The drones could help local communities monitor nearby volcanoes and forecast future eruptions. Their measurements could also tell us more about the most inaccessible, highly active volcanoes on the planet and how volcanoes contribute to the global carbon cycle.
The Manam volcano is located on an island just 10 kilometers (6 miles) wide that sits off the northeast coast of PNG. The island is home to over 9,000 people and Manam Motu, as it's known locally, is one of the most active volcanoes in the country. In 2004, a major eruption from Manam forced the entire island to evacuate to the mainland and devastated people's crops and homes.
Scientists have a few ways of forecasting when a volcano is going to blow. They can monitor earthquake activity in the area to detect tremors which almost always precede eruptions, and look out for bulging in the volcano's sloping walls as magma builds up underneath.
When clear skies allow, satellites can also rapidly detect and measure volcanic emissions of gases such as sulphur dioxide (SO2). Changes to these gas emissions can signal more activity in the volcano below.
"Manam hasn't been studied in detail but we could see from satellite data that it was producing strong emissions," said volcanologist Emma Liu from University College London, who led the research team of earth scientists and aerospace engineers.
"We [also] wanted to quantify the carbon emission[s] from this very large carbon dioxide emitter," added geochemist Tobias Fischer, from the University of New Mexico.
Although volcanoes emit just a fraction of the carbon emissions humans do, researchers still want to be able to estimate what carbon dioxide (CO2) they do emit, to factor this into the carbon budget we have left to limit the effects of climate change.
Traveling to PNG, the international team set about testing two types of long-range drones equipped with gas sensors, cameras, and other devices during two field campaigns on Manam Island, in October 2018 and May 2019.
Manam's steep slopes make it incredibly dangerous to even contemplate collecting gas samples on foot whereas the drones could safely fly right into the billowing plumes, helping the research team measure its volcanic gas emissions more accurately.