Mineral Resources
Electromagnetik and optical seabed exploration
Scientists: Hendrik Müller, Christian Hilgenfeldt, Tilo von Dobeneck
Methods: Marine Electromagnetics and Magnetics, Rock Magnetics
Projects: MARUM Neridis III, SD 1, MARUM-UVigo Neridis II, BGR INDEX

Topics: Marine mineral resources such as hydrothermal polymetallic sulphides, ferromanganese crusts, iron and phosphorite sands stand out by their deviant magnetic and/or conductive properties. We develop and deploy electromagnetic subsea survey systems for the research of precious mineral deposits from coast to deep sea. Integrated benthos cameras assess the morphology and colonization of the seafloor.

Inactive deepsea sulphide chimney (Source: BGR)

Controlled Source Electromagnetic Imaging of the seabed
Scientists: Hendrik Müller, 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:
Müller 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
doi: 10.1190/GEO2010-0129.1

Müller H., von Dobeneck T., Nehmiz W., Hamer K. (2011)
Near-surface electromagnetic, rock magnetic, and geochemical fingerprinting of submarine freshwater seepage at Eckernförde Bay (SW Baltic Sea).
Geo-Marine Letters, 31(2), 123-140
doi: 10.1007/s00367-010-0220-0

Rey D., Müller H., Rubio B., von Dobeneck T., Vilas F., Hilgenfeldt C., Bernabeu A., Frederichs T., Fernández 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

EM exploration of polymetallic sulfide ores in the SW Indian Ocean
Scientists: Hendrik Müller, Christian Hilgenfeldt
Project: BGR INDEX 2014

Summary: Exploration and research activities related to marine mineral resources for the strategic mineral planning gains much importance due to rising commodity prices. However, effective methods to locate the mostly heterogeneous and often deeply covered, shallow marine ore deposits are absent.
In order to evaluate the profitability, one needs to access the spatial extend, the quality and the inner structure of a resource. Mining rights can only obtained from the International Seabed Authority (ISA) on the basis of precise prospection data to justify the required high investment and mining costs. Established marine exploration methods are only of limited suitability to explore Submarine Massive Sulphides (SMS), manganese nodules, phosphorites or heavy mineral placer deposits. In contrast, Controlled Source Electromagnetic (CSEM) imaging is ideal to detect marine resource of contrasting electrical conductivity and/or magnetic properties.

Controlled Source Electromagnetic Deepsea Profiler BGR GoldenEye

Hendrik Müller und Christian Hilgenfeldt develop the new deepsea CSEM system "BGR GoldenEye"

Marum

Intercoast

Intercoast

Intercoast

IODP

MarTech

AWI

British Antarctic

British Antarctic

British Antarctic

British Antarctic

British Antarctic

British Antarctic

Stud.IP

University of Bremen Research group Marine Geophysics
Faculty of Geosciences | FB5