Application of GIS for calculations of geochemical budgets in the marine environment

• Main Authors: Schäfer-Pinto, A., Schlüter, Michael, Sauter, Eberhard, Suess, E.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: 1998
• Subjects: North Atlantic
• Online Access: https://epic.awi.de/id/eprint/4413/; https://hdl.handle.net/10013/epic.14988

A major attempt of geochemical studies is the investigation of the transfer of primary produced biogenic components (e. g. organic carbon or biogenic silica) from surface waters to the deep-sea and their burial in sediments. Particle trap data and investigations of sediments and pore waters provide a suitable data set for the evaluation of such budgets. Nevertheless, these local measurements allow no direct calculation of global or basin-wide geochemical budgets. Major difficulties are the calculation of regions with irregular shape like ocean basins or continental slopes and the spatial extrapolation of flux measurements.Geographic Information Systems (GIS) combine several techniques to solve such problems. GIS allows the exact planimetry of spatial entities and the combination of different information layers like bathymetry, remote sensing data or field measurements by overlay technique. Furthermore GIS enables different geographic projections to controll an appropriate equal area calculation. Gridded ocean-wide data sets permit a cell-by-cell processing, which guarantees no loss of information. By logical queries to a GIS data base, spatial data sets are easily devided into zones of special interests.As an example for the application of GIS the geochemical budget of the organic carbon and biogenic silica fluxes through the sediment-water interface of the northern North Atlantic will be presented. By establishing an empirical relationship based on measured benthic fluxes, water depth and satellite derived primary production rates an area-wide organic carbon flux extrapolation is achieved. Using estimated sediment accumulation rates burial rates are calculated. A similar aproach is used to model biogenic silica flux. Statistical and visual analysis are performed via GIS to controll the extrapolation of data.