HR: 1340h
AN: OS33C-1486    [Abstracts]
TI: A new pore pressure measurement tool for intermediate to long-term in-situ observations - examples from proof-of-concept tests off the Costa Rica margin
AU: * Brueckmann, W
EM: wbrueckmann@ifm-geomar.de
AF: IFM-GEOMAR, Wischhofstr. 1-3, Kiel, 24148 Germany
AU: Pieper, M
OS33C-1486 AF: SFB 574, IFM-GEOMAR, Wischhofstr. 1-3, Kiel, 24148 Germany
AU: Tuerk, M
OS33C-1486 AF: IFM-GEOMAR, Wischhofstr. 1-3, Kiel, 24148 Germany
AB: The cooperative research center (SFB) 574 "Volatiles and Fluids in Subduction Zones" focuses on the flow of volatiles and fluids into and out of subduction zones, that have a significant impact on the long-term geochemical evolution of the hydrosphere and atmosphere. Particular emphasis is placed on the Pacific continental margin of Central America. Off Costa Rica and Nicaragua numerous dewatering features such as mud diapirs, mud volcanoes, and cold seeps have been identified and sampled. To better understand the dynamics of these structures and monitor variations in fluid expulsion and possible correlation with local seismicity the new PPL tool was designed and built. The tool monitors pore pressure changes along a profile in the shallow subsurface using a 2m long stinger with 4 pressure ports. Using a standard IFM-GEOMAR lander the tool can be precisely positioned on and slowly pushed into the seafloor. It can remain on the seafloor for several weeks or months in autonomous mode before being retrieved. We will present data and interpretations from first tests of the PPL tool carried out during R/V METEOR cruise M66/3a off Costa Rica and Nicaragua in the fall of 2005.
UR: http://www.sfb574.geomar.de
DE: 4271 Physical and chemical properties of seawater
DE: 4800 OCEANOGRAPHY: BIOLOGICAL AND CHEMICAL (0460)
DE: 4820 Gases
DE: 4863 Sedimentation (1861)
SC: Ocean Sciences [OS]
MN: Fall Meeting 2005