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Markus Loher

Institution:University of Bremen
Room:GEO, room 1130
Phone:+49 421 218 - 65055
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Other webpage(s):Markus' MARUM web page
Markus Loher

PhD project:

Geological assessment of cold seep dynamics and mud volcanos revealed by high-resolution seafloor data

Submarine mud volcanos are morphological structures consisting of sediment, which has been extruded onto the seafloor from the subsurface. In nature, mud volcanism is favoured by compressive forces for example where two continental plates collide. Together with the eruption of mud and rocks active mud volcanism is usually accompanied by the emission of fluids (gases and/or liquids). Methane (CH4) or higher light-hydrocarbons have been found to be key components of the involved fluids, characteristic for so-called “cold seeps” found at mud volcanos. This seepage-mechanism plays an important role in terms of the complex geochemical cycling occurring at subduction zones, promotes biogeochemical processes in surface sediments and ultimately drives mud volcanism.

In the Calabrian Arc (Ionian Sea) where the African plate subducts below Europe, mud volcanos have been discovered on the accretionary prism. During an expedition of R/V Meteor (M112) high-resolution, geophysical methods shed light on diverse mud volcano morphologies and localised cold seep sites. Active fluid seepage has been observed hydroacoustically and visually at least at one of the structures: the Venere Mud Volcano. Multiple ROV dives were conducted in order to sample and study the fresh sediment outflow centre as well as the fluid emission sites.

In my PhD project, I aim to investigate the past and present activity of mud volcanos and cold seeps along the accretionary prism of the Calabrian Arc. High-resolution bathymetry and video data, sediment cores, seafloor samples, pore fluid and water column measurements will provide the fundamental datasets in order to address research questions such as:
(a) How can the mud volcano morphologies be characterised in detail?
(b) What kinds of fluids are involved in the observed cold-seep activity?
(c) How do mud volcanos evolve over geological timescales and at what are the activity rates of such systems?

Thesis committee:

Prof. Dr. Gerhard BohrmannUniversity of Bremen
Dr. Heiko SahlingUniversity of Bremen
Dr. Miriam RömerUniversity of Bremen
Dr. Jürgen PätzoldUniversity of Bremen
Dr. David VölkerUniversity of Bremen
Prof. Dr. Marta TorresOregon State University, USA