Washington: A team of scientists led by Dr Peter Talling of the UK`s National Oceanography Centre (NOC), currently aboard the Royal Research Ship James Cook, has set sail to map extremely large landslide deposits offshore from an active volcano on Montserrat in the Lesser Antilles.
Active since 1995, the volcano has registered major eruptions and largest volcanic dome collapse occurring in February 2010. These eruptions were monitored on land, and marine surveys were conducted on them.
The survey showed that these collapses caused huge landslides into the ocean to the east and south of the island. Some of these landslides involved over five cubic kilometres of material and travelled underwater for tens of kilometres. They were much larger than even the largest of the volcanic dome collapses since 1995 and probably generated tsunamis, whose magnitude is uncertain.
"We plan to produce the first detailed survey of this type of volcanic flank collapse deposit," said Dr Talling: "For the first time, we will image flank collapse deposits by collecting three-dimensional seismic reflection data, which will show how huge avalanches were emplaced."
The objective of the study is to learn if these landslides can trigger even larger-scale failure of the underlying seafloor sediment using seismic reflection data. Sonar images show huge blocks over 40 metres high and 400 metres long scattered across the seabed. They also depict streaks of material deposited underwater during the February 2010 eruption.
The inhabitants of Montserrat have been relocated to the north of the island following the evacuation of the area around the volcano.
A successful survey could mean the ability to predict future hazards such as tsunamis that these huge landslides could potentially generate.
The research represents a collaborative project between the National Oceanography Centre (NOC), the University of Southampton``s School of Ocean and Earth Sciences, IFM Geomar in Kiel and the Institute de Physique du Globe de Paris (IPGP).