Late glacial to Holocene sortable silt records from the southwestern Labrador Sea Hoffmann, S.S.; Dalsing, R.E.; Murphy, S.C. Hoffmann, S.S. Dalsing, R.E. Murphy, S.C. earth science/paleoclimate/paleocean earth science/paleoclimate/paleocean earth science/paleoclimate/paleocean (V23-18, KN158-4-27 and 28>LATITUDE >LONGITUDE ) The Labrador Sea is a vital region for the Atlantic Meridional Overturning Circulation (AMOC), where overflow waters from the Nordic Seas mix with locally produced Labrador Sea Water, before exiting to the interior of the Atlantic Ocean. The dynamical sedimentary proxy of mean sortable silt size (SS) can give information on past changes in deep water circulation speed and the strength of AMOC. We have produced (SS) records from two core sites at depths between 1500 and 2000 m on the continental slope east of Newfoundland, to reconstruct changes in intermediate depth water circulation speed, including Glacial North Atlantic Intermediate Water and Labrador Sea Water over the past 22,000 years. Increases in (SS) appear to coincide with much of the deglaciation as well as the mid-late Holocene. End-member modeling suggests that ice-rafted debris (IRD) is an important factor in interpreting (SS) during the deglaciation. We find that a robust increase in (SS) is likely unrelated to IRD during the past 5 ka, and probably reflects increased flow at intermediate depths due to local production of LSW strengthening as Nordic Seas overflows weakened at this depth. Our results highlight both the complications of producing (SS) records in IRD-rich, slope environments and the promise that this proxy nevertheless has for reconstructing dynamical changes in deep ocean currents. STUDY NOTES: Site metadata: KN158-4-27 (49.244 N, -48.9877 W, -1846 m, core length: 2.13); KN158-4-28 (49.2433 N, -48.9872 W, -1828 m, core length: 0.36); V23-18 (49 N, -45.017 W, -1593 m, core length: 4.05) Provided Keywords: sediment grain size, sediment geochemistry NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Hoffmann, S.S. Investigator : Dalsing, R.E. Investigator : Murphy, S.C. 2019-05-06 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/26730 https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/hoffmann2019/hoffmann2019-ca_sr.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/hoffmann2019/hoffmann2019-d18o.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/hoffmann2019/hoffmann2019-em.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/hoffmann2019/hoffmann2019-coarse.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/hoffmann2019/hoffmann2019-ca_sr.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/hoffmann2019/hoffmann2019-d18o.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/hoffmann2019/hoffmann2019-em.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/hoffmann2019/hoffmann2019-coarse.txt English https://www.ncdc.noaa.gov/paleo/study/26730 https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/hoffmann2019/hoffmann2019-ca_sr.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/hoffmann2019/hoffmann2019-d18o.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/hoffmann2019/hoffmann2019-em.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/hoffmann2019/hoffmann2019-coarse.txt Hoffmann, S.S., Dalsing, R.E., and Murphy, S.C.2019Sortable silt records of intermediate-depth circulation and sedimentation in the Southwest Labrador Sea since the Last Glacial MaximumQuaternary Science Reviews20699-11010.1016/j.quascirev.2018.12.028 START YEAR: 21342 cal yr BP * END YEAR: 750 cal yr BP -48.9877 49 -45.017 49.244