Volatile und Fluide in Subduktionszonen

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www.ifm-geomar.de/index.php  (Expeditionen 2010) SO 210

The overarching goal of SFB574 is to understand the role of volatiles and fluids in the entire subduction system, because volatiles and fluids cycled through subduction zones have a major influence on short- and long-term climate change, the geochemical evolution of the hydrosphere and atmosphere, and subduction-related natural hazards, such as earthquakes, volcanic eruptions and tsunamis.

Major goals of the proposed cruise are:

1) to investigate the dewatering processes in the forearc of the central Chilean subduction zone, in particular the origin and output flux of vent fluids and volatiles

2) to quantify the amount of fluids and volatiles, such as methane, emitted into the water column

3) to evaluate the role of forearc fluids in triggering mass wasting events that could generate tsunamis

4) to characterize geochemically the subduction sediments, in order to determine the input flux of climate-relevant volatiles (CO2, sulphur and halogens) and a variety of trace elements, necessary for determining the mass balance of chemical fluxes through the subduction system, and

5) to investigate the distribution of volcanic ashes to improve estimates on the volume of material emitted by volcanic eruptions and to date distinct events within the sedimentary sequence. Identification and geochemical investigation of fluid flux, mass wasting and sediments will be performed by acoustic mapping and video-controlled sampling and coring.

Aims/Methods/working area, present knowledge/Logistics of Cruise SONNE SO-210