Further study of volcanoes needed to plan for future eruptions, say researchers
Our understanding of historic volcanic eruptions remains limited despite having detailed records, according to researchers in Edinburgh.
Volcanologists from the British Geological Survey (BGS) studied explosive activity at one of the world’s most active volcanoes, Colima, in Mexico, and suggest that learning from its past behaviour could be key to preparing for future explosions.
The volcano, which is more than 12,470ft (3,800m) high, has erupted more than 50 times since 1519, with the last significant eruption in January 1913.
Dr Julia Crummy, from BGS’s Lyell Centre in Edinburgh, reported her findings in the Journal of Applied Volcanology, and believes they could apply to other volcanoes around the world.
“Current hazard assessments for Colima are based on its last major eruption in 1913, which was about a four on the volcanic explosivity index (VEI),” said Dr Crummy.
“Decades of field studies and laboratory analyses mean that Colima’s eruptions are well-documented.
“However, we had little knowledge of the frequency or magnitude of eruptions that took place at any time before 1519, when the Conquistadors arrived in Mexico and began written observations.
“For the first time, we have modelled the volume and magnitude of five prehistoric explosive events at Colima. These occurred between approximately 4,400 and 6,000 years ago.
“Our results show that we might still underestimate the volume of these eruptions by an order of magnitude. So Colima’s past eruptions may have reached VEI 5.”
Moving up one place on the VEI means an eruption is 10 times as powerful.
In Colima’s case, that means 10 km3 of material could have been blasted from the volcano, instead of 1 km3.
It also means the eruption column height could have been greater than 25 km (15.5 miles).
Dr Crummy said: “Over 500,000 people live within 30 km of Colima, and globally an estimated 800 million people live within 100 km of a volcano that has the potential to erupt, so it is essential that we understand the scale of the hazards involved and collaborate with volcano observatories and disaster risk managers to plan for them accordingly.”
Dr Crummy’s research was funded by the Natural Environment Research Council (NERC), BGS and the Smithsonian Institution.
BGS’s volcanology team works around the world to improve understanding of volcanic processes, hazards and risks.
Through engagement with policy and decision makers, businesses, NGOs and the public, BGS contributes to strategies for disaster risk reduction and mitigation.