IODP Leg 340 - Talling salary

This funding will allow Talling be an onboard scientist for IODP Leg 340 that will drill ten sites around the volcanic islands of Montserrat, Dominica and Martinique in the Lesser Antilles. Leg 340 has three main aims;
1. to better understand the timing and emplacement processes of large volcanic debris avalanches produced by flank collapse, and hence to better understand volcanic and tsunami hazards,
2. to document in unusual detail long term (2-10 Ma) eruptive history to guide prognosis of future volcanic activity (both in the Lesser Antilles and more generally), and to better understand cycles of volcanic island construction and destruction,
3. to document long term magmatic evolution (and how this relates to eruption history and timing of flank collapse) in order to understand how igneous processes (such as partial melting, magma differentiation and transport) generate arc crust.
Six holes will primarily target recent (< 250 ka) debris avalanche deposits offshore Montserrat (CARI 02 & 03), Dominica (CARI 05 & 06), and Martinique (CARI-07 & 08) within the upper 200 m below sea floor. Landslide-derived turbidites and a longer term eruption record will be recovered by four holes outside the debris avalanches. These four holes will recover sediment dating back to ~2-10 Ma.

Leg 340 will provide the first cores to penetrate through a volcanic debris avalanche deposit. Previous drill sites (such as Holes 842/843, 953-956 & 1223 around Canary and Hawaiian Islands) were all located away from avalanche deposits (e.g. in distal turbidites). The emplacement process and consequent tsunami generating potential of these huge collapse events is poorly understood and highly controversial. Combining the IODP cores with 3-d and 2-d seismic data collected previously by NERC will provide powerful new insights into the timing, triggers and emplacement process of debris avalanches.

This project will provide a clearer idea of the volume and emplacement dynamics of debris avalanches, and hence the scale of the tsunami they could generate around Montserrat and adjacent more heavily populated islands. Leg 340 drilling will provide a longer term eruption chronology that will guide the prognosis for future eruptions. This is of obvious and immediate importance to the island's population that has been evacuated to a relative small area in the northern part of the island. Project results will be disseminated initially through the Montserrat Volcano Observatory (MVO). The MVO has a mission to deliver advice to the Montserrat Governor and Government. This advice is of direct benefit to the UK, as Montserrat is a British Dependant Territory. The observatory is now jointly run by the University of West Indies, Seismic Research Unit (SMU) and the Institute de Physique du Globe de Paris (IGPG). The project partners have strong links with the MVO. The next Chief Scientist at the MVO is a project partner (Komorowski), and the project includes other representatives of the SMU (Richardson) and IPGP (Le Friant, Boudon, Deplus), as well a previous MVO Chief Scientist (Sparks). We will use these strong links to disseminate project results effectively to both the Montserrat and UK governments. The IPGP have strong links to other volcanic observatories on the islands of Guadeloupe and Martinique. Project results will contribute to forecasting of volcanic and tsunami hazards for these more densely populated islands.

The results of this IODP Leg will be of interest to local governments for a second reason. There are plans to invest in large scale (up to 50 MW) geothermal power plants on several islands including Montserrat. These power plants would export energy to neighbouring islands via undersea cables. Clearly, it is vital that such cables are routed through areas of the sea bed that are not liable to disruption by submarine sediment flows, debris avalanches or slope failure.

These unique data documenting volcanic debris avalanche timing and emplacement, cycles of volcanic activity, magmatic evolution in the Lesser Antilles will provide a basis for improved hazard assessment for other volcanic island arcs worldwide. We will disseminate this information through conference presentations and high impact journal publications, as well as through governmental channels.