Kristina Sass

Volcanic island sector collapse: Interrelationship of volcanic processes, associated mass movements and subsequent tsunamis

Sector collapses of volcanic islands produce some of the volumetrically largest mass movements on Earth. They may trigger devastating tsunamis that pose hazard to coastal communities and endanger seafloor installations. Accurate tsunami predictions heavily rely on information about the geometry, volume, and kinematics of the triggering event (i.e. the landslide). Very little is currently known about the emplacement processes of flank collapses. Key to the development of a reliable tsunami hazard assessment and prediction is to gain deeper insight into the interplay between different factors (volume, source location, and transport distance) and emplacement processes (timing, kinematics, and dynamics) of sector collapses.

Only few volcanic islands worldwide provide the opportunity to investigate ector collapses. The volcanic island of Montserrat in the Lesser Antilles is an ideal target to study a collapse in the sedimentary record. Southeast of Montserrat, a major landslide deposit (Deposit 2) is located. In 2019, Meteor expedition M154-2 was conducted: In total, six sites within and in the vicinity of Deposit 2 were drilled with MeBo70. Additionally, 21 supplementing gravity cores were taken in the vicinity of MeBo70 drill sites. Hence, Meteor expedition M154-2 provided an outstanding dataset to enable further sediment analyses and therefore a unique opportunity to gain new insights into volcanic island evolution.

Based on the dataset acquired during Meteor expedition M154-2, my Ph.D. project aims at contributing to the general comprehension of volcanic island sector collapses, particularly the interrelationship of volcanic processes, associated mass movements and subsequent tsunami generation. The main goal of my project is the reconstruction of the volume, age, transport distance and source region, as well as the emplacement processes of Deposit 2.