Offshore Gas Hydrate Evaluation on Convergent Margins

• Applicant: Dr. Katrin Schwalenberg
• Subject Area: Geophysics
• Term: from 2003 to 2005
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5410130

The study of gas hydrates is an important research venture in Earth science at the present time. Gas hydrates are ice-like solids and consist of a mixture of water and gas molecules, mainly methane. They are stable at low temperatures and high pressures. Hydrate deposits have been found in sea sediments on continental margins and in permafrost areas. Two aspects are of major interest: The importance as a future energy reserve, and their effect on the world climate. Estimates of available carbon in hydrate exceed the sum in all other known hydrocarbon reserves, like coal, oil and gas. More relevant is the importance as a greenhouse gas. Methane from a fraction of the Earth´s hydrate deposits would double the atmospheric CO2 concentration, if released to the atmosphere. Gas hydrates are generally identified by a strong seismic reflector which marks the base of the hydrate layer. The event is called the Bottom Simulating Reflector (BSR). The existence of hydrate may be deduced from seismic data, the amount of hydrate present is not obtained accurately. A new controlled-source electromagentic (CSEM) sounding method has been developed at the University of Toronto to estimate hydrate concentration in deep-sea sediments. The method is based on the assumption of a reduced electrical conductivity in hydrate rich zones. It has been successfully tested on the Cascadia margin (B.C.). An international project under Chilean patronage with strong German participation has been funded to investigate gas hydrate deposits on the Chilean margin. I will participate in a marine experiment which is scheduled for March 2003 where we apply the CSEM method to derive information about hydrate concentration in the deposit. The obtained data set will offer new perspectives in the development of complementary gas hydrate assessment methods.

• DFG Programme: Research Fellowships
• International Connection: Canada