# Northwest Pacific Productivity Data During the Last Deglaciation #----------------------------------------------------------------------- # World Data Center for Paleoclimatology, Boulder # and # NOAA Paleoclimatology Program #----------------------------------------------------------------------- # NOTE: Please cite original publication, online resource and date accessed when using these data, # If there is no publication information, please cite investigator, title, online resource and date accessed. # # Online_Resource: http://hurricane.ncdc.noaa.gov/pls/paleox/f?p=519:1:::::P1_STUDY_ID:14791 # # Original_Source_URL: ftp://ftp.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/lam2013/lam2013-44pc.txt # # Archive: Paleoceanography #-------------------- # Contribution_Date # Date: 2013-08-16 #-------------------- # Title # Study_Name: Northwest Pacific Productivity Data During the Last Deglaciation #-------------------- # Investigators # Investigators: Lam, P.J.; Robinson, L.F.; Blusztajn, J.; Li, C.; Cook, M.S.; McManus, J.F.; Keigwin, L.D. #-------------------- # Description_and_Notes # # #-------------------- # Publication # Authors: Lam, P.J., L.F. Robinson, J. Blusztajn, C. Li, M.S. Cook, J.F. McManus and L.D. Keigwin # Published_Date_or_Year: 2013 # Published_Title: Transient stratification as the cause of the North Pacific productivity spike during deglaciation # Journal_Name: Nature Geoscience # Volume: 6 # Issue: # Pages: 622-626 # DOI: 10.1038/ngeo1873 # Abstract: During the Bølling–Allerød warm period of the last deglaciation, about 14 kyr ago, there was a strong and pervasive spike in primary productivity in the North Pacific Ocean1. It has been suggested that this productivity event was caused by an influx of the micronutrient iron from surrounding continental shelves as they were flooded by sea-level rise2. Here we test this hypothesis by comparing numerous proxies of productivity with iron flux and provenance measured from a core from the subarctic Pacific Ocean. We find no evidence for an abrupt deglacial pulse of iron from any source at the time of peak productivity. Instead, we argue that the deglacial productivity peak was caused by two stepwise events. First, deep convection during early deglaciation increased nutrient supply to the surface but also increased the depth of the mixed layer, which pushed surface production deeper in the water column and induced light limitation. A subsequent input of meltwater from northern American ice sheets then stratified the water column, which relieved light limitation while leaving the surface waters enriched in nutrients. We conclude that iron plays, at most, a secondary role in controlling productivity during the glacial and deglacial periods in the subarctic Pacific Ocean. # #--------------------- # Funding_Agency # Funding_Agency_Name: # Grant: #--------------------- # Site_Information # Site_Name: RAMA PC-44 # Location: North Pacific # Country: # Northernmost_Latitude: 53.0 # Southernmost_Latitude: 53.0 # Easternmost_Longitude: 164.65 # Westernmost_Longitude: 164.65 # Elevation: -2980 #------------------ # Data_Collection # Core_Name: PC-44 Lam13 # Oldest_Year: 21476 # Most_Recent_Year: 2849 # Time_Unit: cal yr BP # Core_Length: # Notes: Age model from RAMA-PC-44 (Keigwin et al. '92) was modified by recalibrating the radiocarbon dates using the same ΔR as for GGC-37 to allow direct comparison between the cores. Ash shard counts in RAMA-PC-44 were not previously published. #------------------ # Chronology # RAMA-PC-44 Radiocarbon # depth [cm] 14C age [radiocarbon year] error 1 sigma [radiocarbon year] 1 sigma lower limit [calendar year, BP] 1 sigma upper limit [calendar year, BP] mean calibrated age [calendar year, BP] difference (±) probability # 21 6280 70 6040 6622 6331 291 1 # 46 10100 100 10345 11023 10684 339 1 # 71 13000 100 13802 14652 14227 425 0.96 # 14746 14793 14770 23.5 0.04 # 121 14700 100 16771 17259 17015 244 0.87 # 17291 17405 17348 57 0.13 # #------------------ # Variables # # Data line variables format: Variables list, one per line, shortname-tab-9 components: what, material, error, units, seasonality, archive, detail, method, C or N for Character or Numeric data) ## depth_cm depth,,,cm,,,,,N ## age_calkaBP age,,,cal ka BP,,,,,N ## carb% carbonate,,,percent,,paleoceanography,,,N ## opal% opal,,,percent,,paleoceanography,,,N ## shard/g volcanic ash shards,,,per gram,,paleoceanography,,,N ## IRD ice rafted debris,,,#/g,,paleoceanography,,,N #----------------- # DATA # Missing Value: NA depth_cm age_calkaBP carb% opal% shards/g IRD 1 2.849 6.08 13.18 20.66 83 6 3.719 5.32 13.21 12 56 11 4.59 5.31 12.38 64.33 83 16 5.46 6.67 11.56 27.17 184 21 6.331 8.97 11.89 59 40 26 7.202 7.22 11.19 76.81 18 31 8.072 3.23 6.14 392.85 30 36 8.943 14.33 11 6.79 136 41 9.813 13.39 12.09 13.76 220 46 10.684 15.29 15.97 0 65 51 11.393 8.97 13.92 3.43 230 56 12.101 3.41 18.16 0 107 61 12.81 6.27 23.51 0 132 66 13.518 10.18 35.02 0 5 71 14.227 10.54 30.09 0 67 76 14.506 13.36 37.87 0 18 81 14.785 15.12 26.83 0 30 86 15.063 5.7 9.35 0 32 91 15.342 1.95 6.83 0.07 36 96 15.621 1.99 6.36 0 41 101 15.9 1.06 4.01 0 220 106 16.179 0.93 4.98 0.47 489 111 16.457 0.01 5.84 0.77 437 116 16.736 0.56 7.24 0 290 121 17.015 0.33 7.33 0 388 126 17.294 0.56 6.99 NA 1121 131 17.573 0.29 7.79 NA 462 136 17.851 0.27 7.36 NA 325 141 18.13 0.63 6.07 NA 1431 146 18.409 0.39 6.65 NA 599 151 18.688 0.28 5.94 NA 798 156 18.967 0.15 5.92 NA 656 161 19.245 0.29 6.94 NA 618 166 19.524 0.59 6.96 NA NA 171 19.803 0.34 7.39 NA NA 176 20.082 0.2 6.5 NA NA 181 20.361 0.32 6.19 NA NA 186 20.639 0.15 7.69 NA NA 191 20.918 0.14 7.45 NA NA 196 21.197 0.14 6.51 NA NA 201 21.476 0.27 6.18 NA NA