Final Report Summary - NOGOS (Noble gases in ocean sediments as proxies for fluid transport at subduction zones and past climate conditions)
In order to widen and further stimulate the use of noble-gas geochemistry in sediment pore waters the research project aimed to systematically apply the state-of-the-art of noble-gas analysis to ocean sediments.
The researcher studied the fluid transport along the Nankai Trough near the forearc region off shore Japan. The investigated region is expected to be hit by an earthquake in the future. He isotopes allowed for the first time studying the release dynamics of deep fluid seepages in this tectonically active region. Moreover, the investigation of the noble-gas signature in the pore water sets a first data basis to interpret noble-gas anomalies in regions where major earthquakes occurred or will occur. This work is a further step towards the use noble gases in terrestrial fluids as indicator of seismic activity.
Although recently noble gases in pore water of lacustrine sediments allow the determination of lake level and salinity fluctuations, and the reconstruction of past environmental conditions and past eutrophic states in lakes, assessment of noble gases in ocean sediments is not yet fully developed due to the limitations of the presently available experimental techniques (e.g. degassing affecting ICDP/IODP deep-drilling sediments). Based on the experience gained in oceanography during this fellowship, the researcher developed a conceptual approach to overcome the restrictions that still limit the application of noble gases in deep sediments from the oceans using newly developed on-line mass-spectrometric techniques.
The researcher studied the fluid transport along the Nankai Trough near the forearc region off shore Japan. The investigated region is expected to be hit by an earthquake in the future. He isotopes allowed for the first time studying the release dynamics of deep fluid seepages in this tectonically active region. Moreover, the investigation of the noble-gas signature in the pore water sets a first data basis to interpret noble-gas anomalies in regions where major earthquakes occurred or will occur. This work is a further step towards the use noble gases in terrestrial fluids as indicator of seismic activity.
Although recently noble gases in pore water of lacustrine sediments allow the determination of lake level and salinity fluctuations, and the reconstruction of past environmental conditions and past eutrophic states in lakes, assessment of noble gases in ocean sediments is not yet fully developed due to the limitations of the presently available experimental techniques (e.g. degassing affecting ICDP/IODP deep-drilling sediments). Based on the experience gained in oceanography during this fellowship, the researcher developed a conceptual approach to overcome the restrictions that still limit the application of noble gases in deep sediments from the oceans using newly developed on-line mass-spectrometric techniques.