Climate change may influence volcanic eruptions

Changes in sea level can influence volcanic eruptions, according to new research led by Oxford Brookes University. 

Climate change may influence volcanic eruptions

The researchers analysed the timings of eruptions over hundreds of thousands of years and found that a 40-meter fall in sea level is a crucial point beyond which eruptions are more likely to occur. 

Dr Satow, lead author of the research said: ‘The climate can also affect volcanoes. As ice sheets retreated across volcanic landscapes after the last ice age, the removal of mass changed the stress conditions in the Earth’s crust, allowing the fractures which feed volcanic eruptions to form more easily.

‘As these ice sheets melted the global sea level rose rapidly, by around 100 meters, adding a significant mass to the crust around many volcanic islands which, in theory, should alter their eruptive activity.’

With 57% of the world’s volcanoes located on islands or densely populated coastal areas, the researchers have highlighted that further research is urgently needed to fully understand how the effects of changing sea levels with climate change will put populations at risk. 

Dr Satow added: ‘A huge eruption 3,600 years ago caused the centre of what was then a conical island to sink into the sea, revealing an extraordinarily detailed history of over 200 volcanic eruptions preserved within the remaining circle of cliffs.

‘Comparing this eruption history to a sea-level record allowed us to show for the first time that the sea level has had an important role in determining the timing of eruptions at Santorini, and probably at many other island volcanoes around the world.

‘The mechanism is quite simple: falling sea levels remove mass from the Earth’s crust and the crust fractures as a result. These fractures allow magma to rise and feed eruptions at the surface.

‘Just as when you pull a plug out of the bath, the water level drops everywhere throughout the bath at the same time; in a similar way, sea-level changes occur at the same time everywhere across the globe.’