"Currently, much of the thinking around risks posed by volcanoes follows a simple equation: the bigger the likely eruption, the worse it will be for society and human welfare.
Researchers led by the University of Cambridge’s Centre for the
Study of Existential Risk (CSER) have identified seven “pinch points” where clusters of relatively small but active volcanoes sit alongside vital infrastructure that, if paralyzed, could have catastrophic global consequences.These regions include volcano groups in Taiwan, North Africa, the North Atlantic, and the northwestern United States. The report is published today (August 6, 2021) in the journal Nature Communications.
Mani and colleagues say that smaller eruptions ranking up to 6 on the “volcanic explosivity index”– rather than the 7s and 8s that tend to occupy catastrophist thinking – could easily produce ash clouds, mudflows, and landslides that scupper undersea cables, leading to financial market shutdowns, or devastate crop yields, causing food shortages that lead to political turmoil.
As an example from recent history, the team point to events of 2010
in Iceland, where a magnitude 4 eruption from the Eyjafjallajökull
volcano, close to the major “pinch point” of mainland Europe, saw plumes
of ash carried on northwesterly winds close European airspace at a cost
of US$5 billion to the global economy." SciTechDaily