Volcanic eruptions in the marine environment: new results thanks to the international Fire&Ice expedition

Giulia Matilde Ferrante from the OGS recently took part in an oceanographic mission off the coast of northern Patagonia. The campaign, called Fire&Ice, lasts three weeks and involves an international team of scientists from the UK, Chile, Italy, the US, New Zealand and Malta. The aim of the project is to better understand the impact of eruptions on the marine environment and human infrastructure.

The 2008 eruption of the Chaitén volcano in Chile had a major impact on the area and local communities after 9,000 years of dormancy, flushing enormous amounts of ash and dust into the sea. The Fire&Ice mission, which took place on board the Schmidt Ocean Institute's research vessel Falkor (too), used state-of-the-art technology and a remotely operated submarine to collect and analyse samples of these volcanic sediments. Traces of the eruption were found up to 25 kilometres from Chaitén, but the analyses actually covered a much larger area, stretching from the northern Patagonian Sea to the Atacama Trench.

The sediment layers obtained from the drill cores are direct evidence of geological and palaeoceanic activity in the region. According to Sebastian Watt, "it'll also be possible to "reconstruct the impact of volcanoes on the marine environment and on anthropogenic infrastructure in the sea, such as fishing and telecommunications".

A new mapping of 2700 square kilometres of the coastal seabed was also carried out, revealing, among other things, the glacial morphology and the presence of huge underwater megadunes formed by volcanic sediments that had accumulated at the mouth of a river.

However, the oceanographic campaign not only had a scientific value, but also an important social one. Researchers from three Chilean universities and the Chilean National Geological and Mining Service (SERNAGEOMIN) worked together with the local communities of Chaitén to raise awareness of the volcanic risks and the importance of protecting the marine environment.

Photo credits: Alex Ingle / Schmidt Ocean Institute