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<oai_dc:dc xmlns:oai_dc="http://www.openarchives.org/OAI/2.0/oai_dc/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/oai_dc/ http://www.openarchives.org/OAI/2.0/oai_dc.xsd">
  <dc:title xmlns:dc="http://purl.org/dc/elements/1.1/">1991 Marine Biological Association (MBA) Witch Ground Basin RRS Challenger Cruise 82 sediment cores and gas sampling</dc:title>
  <dc:type xmlns:dc="http://purl.org/dc/elements/1.1/">dataset</dc:type>
  <dc:identifier xmlns:dc="http://purl.org/dc/elements/1.1/">https://portal.medin.org.uk/portal/start.php?tpc=010_fafe6be12e831f965fbc3f43ab1adbd7</dc:identifier>
  <dc:description xmlns:dc="http://purl.org/dc/elements/1.1/">The objectives of Leg 1 of this survey were:
 - To locate the source of hydrogen plumes in the Witch Ground Basin by taking water samples with the rosette sampler.
 - To take core samples from the 2 large pockmarks in UK Block 15/25 to obtain Astomonema and other samples needed to complete studies on these pockmarks.
 - To re-survey the extent of the shallow gas deposits mapped in 1990.
 Leg 2:
 - To map the distribution of shallow gas and gas seeps in the Skagerrak north of Hirtshals and to study the relationship of the seeps to bottom and sub-bottom topography.
 - To obtain sediment cores from methane-rich and methane-poor sediments in order to compare their biomass, species composition and geochemistry.
 - To collect fauna for stable isotope analysis, for biochemical studies and for electron microscopy.
 - To measure gas concentrations and bacterial activity in the sediments and in the water collumn.</dc:description>
  <dc:date xmlns:dc="http://purl.org/dc/elements/1.1/">20211223 19910728</dc:date>
</oai_dc:dc>