Keigwin, Lloyd D; Guilderson, Thomas P (2009): (Table 1) Age determination of surface sediment samples from the North Atlantic [dataset]. PANGAEA, https://doi.org/10.1594/PANGAEA.831644, Supplement to: Keigwin, LD; Guilderson, TP (2009): Bioturbation artifacts in zero-age sediments. Paleoceanography, 24(4), PA4212, https://doi.org/10.1029/2008PA001727
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Abstract:
Most seafloor sediments are dated with radiocarbon, and the sediment is assumed to be zero-age (modern) when the signal of atmospheric testing of nuclear weapons is present (Fraction modern (Fm) > 1). Using a simple mass balance, we show that even with Fm > 1, half of the planktonic foraminifera at the seafloor can be centuries old, because of bioturbation. This calculation, and data from four core sites in the western North Atlantic indicate that, first, during some part of the Little Ice Age (LIA) there may have been more Antarctic Bottom Water than today in the deep western North Atlantic. Alternatively, bioturbation may have introduced much older benthic foraminifera into surface sediments. Second, paleo-based warming of Sargasso Sea surface waters since the LIA must lag the actual warming because of bioturbation of older and colder foraminifera.
Related to:
Keigwin, Lloyd D; Pickart, Robert (1999): Slope water current over the Laurentian Fan on interannual to millennial time scales. Science, 286(5439), 520-523, https://doi.org/10.1126/science.286.5439.520
Ohkouchi, Naohiko; Eglinton, Timothy Ian; Keigwin, Lloyd D; Hayes, John M (2002): Spatial and temporal offsets between proxy records in a sediment drift. Science, 298(5596), 1224-1227, https://doi.org/10.1126/science.1075287
Coverage:
Median Latitude: 39.090800 * Median Longitude: -60.150950 * South-bound Latitude: 33.693500 * West-bound Longitude: -72.292000 * North-bound Latitude: 43.483300 * East-bound Longitude: -54.867000
Date/Time Start: 2004-06-23T00:00:00 * Date/Time End: 2004-06-23T00:00:00
Minimum DEPTH, sediment/rock: 0 m * Maximum DEPTH, sediment/rock: 0 m
Event(s):
KNR178-1-1-1 * Latitude: 36.120200 * Longitude: -72.292000 * Date/Time: 2004-06-23T00:00:00 * Elevation: -3979.0 m * Recovery: 0.45 m * Location: North Atlantic * Campaign: KNR178 * Basis: Knorr * Method/Device: MultiCorer (MUC)
OCE326-BC9 * Latitude: 33.693500 * Longitude: -57.611000 * Elevation: -4600.0 m * Location: North Atlantic * Method/Device: Box corer (BC) * Comment: Bermuda Rise 1998
Parameter(s):
| # | Name | Short Name | Unit | Principal Investigator | Method/Device | Comment |
|---|---|---|---|---|---|---|
| 1 | Event label | Event | ||||
| 2 | Latitude of event | Latitude | ||||
| 3 | Longitude of event | Longitude | ||||
| 4 | Elevation of event | Elevation | m | |||
| 5 | Laboratory code/label | Lab label | Keigwin, Lloyd D | |||
| 6 | DEPTH, sediment/rock | Depth sed | m | Geocode | ||
| 7 | Age, dated material | Dated material | Keigwin, Lloyd D | |||
| 8 | Fraction modern carbon | F14C | Keigwin, Lloyd D | |||
| 9 | Fraction modern carbon, error | F14C e | ± | Keigwin, Lloyd D | ||
| 10 | Age, dated | Age dated | ka | Keigwin, Lloyd D | Age, 14C AMS | |
| 11 | Age, dated standard deviation | Age dated std dev | ± | Keigwin, Lloyd D | Age, 14C AMS | |
| 12 | Δ14C | Δ14C | ‰ | Keigwin, Lloyd D | ||
| 13 | Reference/source | Reference | Keigwin, Lloyd D |
License:
Creative Commons Attribution 3.0 Unported (CC-BY-3.0)
Size:
51 data points