# Deglacial North East Pacific Radiocarbon and Boron Isotope Data from MD02-2489 #----------------------------------------------------------------------- # World Data Center for Paleoclimatology, Boulder # and # NOAA Paleoclimatology Program #----------------------------------------------------------------------- # NOTE: Please cite original publication, online resource and date accessed when using this data. # If there is no publication information, please cite Investigator, title, online resource and date accessed. # # Online_Resource: http://www.ncdc.noaa.gov/paleo/study/16648 # # Online_Resource: ftp://ftp.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/rae2014/rae2014-t7.txt # # Archive: Paleoceanography # #-------------------------------- # Contribution_Date # Date: 2014-06-18 #-------------------------------- # Title: Deglacial North East Pacific Radiocarbon and Boron Isotope Data from MD02-2489 #-------------------------------- # Investigators: Rae, J.W.B.; Sarnthein, M.; Foster, G.L.; Ridgwell, A.; Grootes, P.M.; Elliott, T. #-------------------- # Description and Notes: # The data given here include age models, boron isotope data analysed by MC-ICPMS, and radiocarbon data analysed by AMS. # # Keywords from PI: Radiocarbon; Boron isotopes; North Pacific; Deglacial CO2; Deep water formation; #-------------------- # Publication # Authors: Rae, J.W.B., M. Sarnthein, G.L. Foster, A. Ridgwell, P.M. Grootes, and T. Elliott # Journal_Name: Paleoceanography # Published_Title: Deep water formation in the North Pacific and deglacial CO2 rise # Published_Date_or_Year: 2014 # Volume: # Pages: # DOI: 10.1002/2013PA002570 # Abstract: Deep water formation in the North Atlantic and Southern Ocean is widely thought to influence deglacial CO2 rise and climate change; here we suggest that deep water formation in the North Pacific may also play an important role. We present paired radiocarbon and boron isotope data from foraminifera from sediment core MD02-2489 at 3640 m in the North East Pacific. These show a pronounced excursion during Heinrich Stadial 1, with benthic-planktic radiocarbon offsets dropping to ~350 years, accompanied by a decrease in benthic δ11B. We suggest this is driven by the onset of deep convection in the North Pacific, which mixes young shallow waters to depth, old deep waters to the surface, and low-pH water from intermediate depths into the deep ocean. This deep water formation event was likely driven by an increase in surface salinity, due to subdued atmospheric/monsoonal freshwater flux during Heinrich Stadial 1. The ability of North Pacific Deep Water (NPDW) formation to ex plain the excursions seen in our data is demonstrated in a series of experiments with an intermediate complexity Earth system model. These experiments also show that breakdown of stratification in the North Pacific leads to a rapid ~30 ppm increase in atmospheric CO2, along with decreases in atmospheric δ13C and Δ14C, consistent with observations of the early deglaciation. Our inference of deep water formation is based mainly on results from a single sediment core, and our boron isotope data are unavoidably sparse in the key HS1 interval, so this hypothesis merits further testing. However we note that there is independent support for breakdown of stratification in shallower waters during this period, including a minimum in δ15N, younging in intermediate water 14C, and regional warming. We also re-evaluate deglacial changes in North Pacific productivity and carbonate preservation in light of our new data, and suggest that the regional pulse of export production observe d during the Bølling-Allerød is promoted by relatively stratified conditions, with increased light availability and a shallow, potent nutricline. Overall, our work highlights the potential of NPDW formation to play a significant and hitherto unrealized role in deglacial climate change and CO2 rise. #-------------------------------- # Funding_Agency: # Funding_Agency_Name: Natural Environment Research Council # Grant: NE/I017240/1, NE/C00876X/2 #-------------------------------- # Funding_Agency: # Funding_Agency_Name: NOAA/UCAR Climate and Global Change Postdoctoral Fellowship Program # Grant: #-------------------------------- # Funding_Agency: # Funding_Agency_Name: Deutsche Forschungsgemeinschaft # Grant: #-------------------------------- # Site Information: # Site_Name: MD02-2489 # Location: Eastern Pacific Ocean # Northernmost_Latitude: 54.39 # Southernmost_Latitude: 54.39 # Easternmost_Longitude: -148.92 # Westernmost_Longitude: -148.92 # Elevation: -3640 #-------------------------------- # Data Collection # Collection_Name: MD02-2489 Tab7-14C Planktic R14 # Oldest_Year: 19623 # Most_Recent_Year: 7600 # Time_Unit: cal yrBP # Core_Length # Notes: Table 7: planktic 14C data for MD02-2489 #-------------------------------- # Chronology: # #-------------------------------- # Variables # # Data variables follow (have double marker- "##") # Data line variables format: Variables list, one per line, shortname-tab-nine components: what, material, error, units, seasonality, archive, detail, method, C or N for Character or Numeric data) ## depth_cm depth,,,cm,,,,,N ## age_calkaBP-d18 age,,,calendar kyr before 1950AD,,,using d18O ties,,N ## age_calkaBP-plat age,,,calendar kyr before 1950AD,,,plateau-tuned,,N ## age_14C.raw-plank age,raw conventional 14C planktic forams,,14C years before 1950AD,,paleoceanography,,,N ## age_14C.raw-plank_err age,raw conventional 14C planktic forams,1-sigma error,14C years before 1950AD,,paleoceanography,,,N ## D14C-plank Delta 14C,planktic forams,,per mil VPDB,,paleoceanography,relative to VPDB standard and corrected for mass dependent isotope fractionation,,N ## DD14C-plank Delta Delta 14C,Difference between planktic foraminifera and the contemporaneous atmosphere units,,per mil VPDB,,paleoceanography,,,N ## age_plank-atm age,Difference between planktic foraminifera and the contemporaneous atmosphere units,,14C years before 1950AD,,paleoceanography,,,N ## notes notes,,, ,,,,,C # Data: # Missing Value: NaN depth_cm age_calkaBP-d18 age_calkaBP-plat age_14C.raw-plank age_14C.raw-plank_err D14C-plank DD14C-plank age_plank-atm 59 7600 7600 7570 40 -23 -107 856 KIA23972 66.5 8802 8802 8715 45 -20 -98 790 KIA34750 76.5 9421 9421 9210 50 -7 -103 815 KIA34751 86.5 10560 10560 10140 70 15 -105 817 KIA34752 96 11920 11920 11080 60 65 -123 903 KIA34753 110 12898 12898 11870 30 86 -121 873 KIA25503 119 13151 13151 12120 70 86 -124 891 KIA34754 130 13588 14050 12730 35 61 -139 1016 KIA25504 140 13986 14289 12840 70 98 -99 716 KIA35318 150.75 14266 14547 12918 65 125 -80 566 KIA26539 156 14387 14673 13250 70 95 -120 861 KIA35319 160 14479 14768 11935 45 NaN NaN NaN KIA26540; this anomalously young 14C age likely caused by contamination due to a core break at this interval - see Gebhardt et al. 2008 Fig. S2. 163 14548 14840 12920 90 164 -70 481 KIA34755 165.5 14606 14900 12800 90 189 -51 346 KIA35320 171.5 14843 15250 13820 80 78 -186 1313 KIA34756 177.5 15114 15517 13990 80 91 -186 1303 KIA35321 181.5 15295 15694 13850 80 135 -146 1002 KIA34757 184.5 15431 15828 14030 80 128 -164 1124 KIA35322 189.5 15656 16050 14180 80 138 -169 1143 KIA35323 192 15769 16130 14500 70 108 -201 1380 KIA23973 195.5 15927 16241 14270 80 162 -156 1039 KIA35324 200.5 16230 16400 14430 90 182 -142 940 KIA34758 204.5 16479 16667 15050 90 128 -201 1358 KIA35325 209.5 16790 16955 15580 90 96 -262 1771 KIA35326 212.5 16977 17064 15500 95 132 -236 1563 KIA34759 217.5 17289 17245 15350 90 198 -178 1147 KIA35327 223.5 17662 17563 16060 80 147 -244 1596 KIA34760 231 18000 18000 16750 105 97 -306 2032 KIA35328 237 18180 18316 16830 105 110 -295 1947 KIA35329 248 18557 18895 16867 65 156 -252 1628 KIA26541 254.5 18903 19123 17300 90 143 -256 1670 KIA34761 268 19623 19491 18042 65 137 -300 1939 KIA26550