highlow, Pacific, nativereconstructed, Lamy

Core/Site name:

GeoB 3313-1

Country/Region:

Southeast Pacific, Chile margin

Elevation:

-852

Archive:

marine sediments (downcore)

Species:

Neogloboquadrina pachyderma (dextral).

Proxy measurement:

alkenone, o18, opal%, Corg%

Sampling resolution:

decadal

Climate sensitivity:

temperature, salinity, productivity

Dating resolution:

radiometric, 7 dates, 260-7090 yrs, min resolution 10 yrs

Startyear:

7090 cal yr BP

Endyear:

260 cal yr BP

Description:

We reconstructed changes of temperature, salinity, and productivity within the southern Peru-Chile Current during the last 8000 years from a high-resolution sediment core recovered at 41°S using alkenones, isotope ratios of planktic foraminifera, biogenic opal, and organic carbon. Paleotemperatures and paleosalinities reached maximum values at ~5500 years ago and thereafter declined to modern values, whereas paleoproductivity continuously increased throughout the last 8000 years. We ascribe these long-term Holocene trends primarily to latitudinal shifts of the Antarctic Circumpolar Current (ACC). The concurrence with shifts in the position of the Southern Westerlies points to a common response of atmospheric and oceanographic circulation patterns off southern Chile. Millennial- to centennial-scale fluctuations of paleotemperatures and paleosalinities, on the other hand, lag displacements in the position of the Southern Westerlies but reveal a significant correlation to short-term temperature changes in Antarctica, indicating a high-latitude control of the ACC at these timescales.

Data entered by name:

Kohfeld, Karen E.

Data entered by email:

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Main reference(s):

Lamy, F., C. Rühlemann, D. Hebbeln, and G. Wefer. 2002. High- and low-latitude climate control on the position of the southern Peru-Chile Current during the Holocene. Paleoceanography 17(2):1028.Lamy, F., D. Hebbeln, U. Röhl, and G. Wefer. 2001. Holocene rainfall variability in southern Chile: a marine record of latitudinal shifts of the Southern Westerlies. Earth and Planetary Science Letters 185(3-4):369-382.

Link to reference 1:

http://www.agu.org/journals/pa/pa0202/2001PA000727/

Link to reference 2:

http://www.sciencedirect.com/science/article/pii/S0012821X00003812

Data storage link 1:

ftp://ftp.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/lamy2002/

Data storage link 2:

ftp://ftp.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/lamy2002/readme_lamy2002.txt

Current dating method:

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Annual snow acc rate:

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Category: Ocean2k