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Anomalous temperatures in central Scotia Sea sediments – Bottom water variation or pore water circulation in old ocean crust
Author(s) -
Barker Peter F.,
Lawver Lawrence A.
Publication year - 2000
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/1999gl008381
Subject(s) - weddell sea bottom water , geology , antarctic bottom water , oceanography , bottom water , advection , circumpolar deep water , seabed , ocean current , climatology , thermohaline circulation , north atlantic deep water , ice shelf , sea ice , cryosphere , physics , thermodynamics
We report low temperature gradients (from 60% to 12% of geothermal), and extrapolated temperatures offset from modern bottom water temperatures, in sediments from the central Scotia Sea. We examine possible causes, bearing in mind similar anomalous measurements 18 years previously, attributed at the time to instrumental error. Small temperature offsets (±0.1°C) may reflect short‐term bottom temperature variation within eddies of the Antarctic Circumpolar Current. Low sediment temperature gradients may be caused by horizontal advection of cold water within the upper oceanic basaltic layer (documented in younger ocean floor elsewhere), or by northward encroachment of colder bottom waters (from the Antarctic Peninsula shelf or Weddell Sea) for several years prior to measurement.