MARINE GEOLOGY AND GLACIOLOGY
Galathea 3: WINMARGIN Project

	Researchers   Antoon Kuijpers - aku@geus.dk
Fig. 1 Bathymetry of Caribbean waters around the former Danish West Indies with a tentative multi-channel seismic grid (red lines) and detailed survey area (ligh red) in the southern part of the Anegada-Jungfern Passage.

WEST INDIES MARINE GEOSCIENCE INVESTIGATIONS

Plate tectonics and earthquakes, hurricanes, and ocean circulation changes

The history of the northeast Caribbean (former) Danish West Indies is known for passage of numerous hurricanes and repeated occurrence of tsunamis causing great damage to human life and buildings. Strong earthquakes associated with collision of the Caribbean and North American Plate led to several disastrous tsunamis as, for instance, in November 1867, when ships anchoring off Charlotte Amalie (St. Thomas) were wrecked and numerous people killed. Severe tropical cyclones (hurricanes) have their origin in the tropical Atlantic and typically occur in the period July to October. Their frequency depends, apart from sea surface temperature, also on the prevailing large-scale atmospheric circulation pattern.

Fig. 2a University of the Virgin Islands (UVI), St Thomas (project partner).

The warm ocean waters of the northeast Caribbean region significantly contribute to the Gulfstream and North Atlantic Current responsible for generally mild northwest European winter climate. Oceanographically important in the study area is the up to c. 4800 m deep Anegada-Jungfern Passage (Fig. 1) which forms a conduct for deep water exchange between the North Atlantic and deep Caribbean. Colder subsurface (intermediate) water masses from the Southern Hemisphere (Antarctic Intermediate Water) are also found here.

With seismic and acoustic methods and sediment core records to explore the geological history supplied by hydrographic measurements the main objective of the project is:

1. to improve our knowledge of regional plate tectonic setting and sediment stability (tsunami risk), and
2. to trace possible links between oceanographic changes and North Atlantic (e.g. hurricane) climate variability, with the ultimate aim of better understanding possible influences of the tropical Atlantic on high-latitude climate. In addition, relevant land-based studies are also planned.

Fig. 2b.View on the Caribbean, from the MacLean Marine Science Center, UVI

The project is financially supported by the “Villum Kann Rasmussen Foundation”. Project leader is Antoon Kuijpers, while the work is a joint effort of GEUS, Aarhus University (Holger Lykke Andersen, Marit-Solveig Seidenkrantz) , Copenhagen University (Jesper Bartholdy, Christian Christiansen, Helmar Kunzendorf), Göteborg University (Björn Malmgren) and University of the Virgin Islands (Roy A. Watlington), St. Thomas (see Fig. 2a, b).

Edited by:
Niels E. Poulsen, GEUS - nep@geus.dk