Scientists: Hendrik MÃ¼ller, Benjamin Baasch, Christian Hilgenfeldt, Tilo von Dobeneck
Projects: MARUM Sediment Dynamics SD1, MARUM Neridis III, MARUM-UVigo Neridis II
Summary: Given the environmental and economic relevance of ocean margins and their geophysical exploration, there is growing need to characterize surficial sediments in coastal and continental shelf systems by more than just their acoustic properties. A newly conceptualized benthic profiling and data processing approach based on controlled source electromagnetic (CSEM) imaging permits to coevally quantify the electric conductivity (~ salinity, porosity and grain-size variations) and the magnetic susceptibility (~ terrigenous or iron mineral content, redox state and contamination level) of shallow marine deposits. This approach has been successfully applied in a number of estuarine and shelf surveys with the first and second generation of the Neritic Discoverer (NERIDIS II & III). The narrow footprint of the concentric, coaxial CSEM sensor together with a relatively high sampling rate (25 Hz) and tow speed (up to 3-4 knots) enable to cover and resolve sediment patterns of very different lateral extent from sub-meter (e.g., iron sulfide nodules, UXO) to kilometer scales (e.g., drift bodies, placer deposits) within the same survey operation.
Controlled Source Electromagnetic Seabed Profiler MARUM Neridis III
|Selected Publications: |
MÃ¼ller H., von Dobeneck T., Hilgenfeldt C., SanFilipo B., Rey D., Rubio B. (2012)
Mapping the magnetic susceptibility and electric conductivity of marine surficial sediments by benthic EM profiling
Geophysics, 77, E43 - E56
MÃ¼ller H., von Dobeneck T., Nehmiz W., Hamer K. (2011)
Near-surface electromagnetic, rock magnetic, and geochemical fingerprinting of submarine freshwater seepage at EckernfÃ¶rde Bay (SW Baltic Sea).
Geo-Marine Letters, 31(2), 123-140
Rey D., MÃ¼ller H., Rubio B., von Dobeneck T., Vilas F., Hilgenfeldt C., Bernabeu A., Frederichs T., FernÃ¡ndez S., Mohamed K. (2008)
Using electromagnetic sensors to estimate physical properties and environmental quality of surface sediments in the marine environment. Preliminary results.
Geotema, 10 , 652 - 654