# 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-ggc37-foram.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: V19-4 GGC37 # Location: North Pacific # Country: # Northernmost_Latitude: 50.42 # Southernmost_Latitude: 50.42 # Easternmost_Longitude: 167.731667 # Westernmost_Longitude: 167.731667 # Elevation: -3300 #------------------ # Data_Collection # Core_Name: GGC37 Lam13 Foram # Oldest_Year: 23285 # Most_Recent_Year: 3461 # Time_Unit: cal yr BP # Core_Length: # Notes: Previously published d18O and benthic foraminiferal abundance measurements (Keigwin '98) were made on subsamples taken from the working half of core GGC-37. # All other measurements were made on subsamples taken from the archive half of core GGC-37 and corrected for a four-centimetre offset # between the working and archive halves. Age is median age of sample. #------------------ # Chronology # GGC37 Radiocarbon # Depth range (working half) [cm] Depth range (archive half equivalent) [cm] Depth center (archive half equivalent) (cm) 14C age [radiocarbon year] error 1 sigma [radiocarbon year] median cal age 1 sigma lower limit [calendar year, BP] 1 sigma upper limit [calendar year, BP] # 0-2 4-6 5 3930 65 3461 3151 3807 # 17-19 21-23 22 8200 80 8313 8000 8575 # 23-25 27-29 28 9420 95 9801 9505 10140 # 31-35 35-39 37 10050 140 10579 10229 11000 # 41-43 45-47 46 12420 100 13518 13266 13786 # 49-51 53-55 54 12910 95 14133 13705 14575 # 55-57 59-61 60 12800 115 13964 13454 14456 # 57-59 61-63 62 13150 100 14492 14036 14926 # 63-65 67-69 68 12800 100 13959 13453 14451 # 71-73 75-77 76 13300 100 14694 14160 15111 # 83-85 87-89 88 13700 130 15578 15065 16305 # 111-113 115-117 116 16650 130 19072 18850 19375 # 143-145 147-149 148 20100 180 23037 22589 23416 # # Dates at 42, 58 and 64 cm were not used because they fall on the shoulders of the productivity peak, and are probably biased by bioturbation. For the same reason dates from 50 and 56 cm in the peak were averaged. # Calendar age was calculated with Calib 6.0 and the Intcal09 calibration dataset, using a constant reservoir age anomaly (ΔR) of 370±250 years. Ages were assigned to each sample depth by linear interpolation between # the remaining radiocarbon dates. # #------------------ # 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-work depth,working half of GGC37,,cm,,,,,N ## depth_cm-arc depth,archive half of GGC37,,cm,,,,,N ## age_calkaBP age,,,cal ka BP,,,,,N ## U.auber/g Uvigerina auberiana abundance,,,#/g,,paleoceanography,,,N ## d18On.pachy-l delta 18O,N. pachyderma left coiling,,per mil PDB,,paleoceanography,,,N ## d18Ocibid delta 18O,Cibicidoides sp.,,per mil PDB,,paleoceanography,,,N #----------------- # DATA # Missing Value: NA depth_cm-work depth_cm-arc age_calkaBP U.auber/g d18On.pachy-l d18Ocibid 1 5 3.461 0.13 2.52 3 4 8 4.317 0.12 2.19 3 6 10 4.888 0 2.3 3 10 14 6.03 0.13 2.33 3.2 12 16 6.601 0.13 2.18 3.2 14 18 7.171 0.2 2.34 3.2 16 20 7.742 0.34 2.3 3.2 18 22 8.313 0.27 2.12 3.3 20 24 8.809 0.08 2.37 3.4 22 26 9.305 0.17 2.65 3.4 24 28 9.801 0.64 2.49 3.6 26 30 9.974 0.18 2.42 NA 28 32 10.147 0.43 2.52 3.3 30 34 10.32 0.68 2.68 3.3 32 36 10.493 0.59 2.59 3.2 34 38 10.752 0.57 2.83 3.5 36 40 11.099 1.97 2.97 3.9 38 42 11.446 0.97 3.08 3.8 40 44 11.793 2.69 3.06 3.9 42 46 12.14 2.95 3.16 4.1 44 48 12.487 5.38 3.06 4.1 46 50 12.834 8.81 3.02 NA 48 52 13.181 8.52 3 NA 50 54 13.528 15.71 3.03 NA 52 56 13.875 13.19 2.97 NA 54 58 14.082 8.06 2.93 4 56 60 14.15 17.27 2.97 4 58 62 14.218 3.19 2.93 4.2 60 64 14.286 2.34 2.81 NA 62 66 14.354 2.33 NA 4.3 64 68 14.422 2.59 2.61 NA 66 70 14.49 2.41 2.78 4.1 68 72 14.558 2.41 3.3 NA 70 74 14.626 1.2 3.44 4.1 72 76 14.694 0.74 3.33 4.1 74 78 NA NA NA 4.1 76 80 14.989 0.6 3.51 4.2 78 82 NA NA NA 4.2 80 84 15.283 0.47 3.45 4.2 82 86 NA NA NA 4.3 84 88 15.578 0.48 3.48 4.4 86 90 NA NA NA 4.4 88 92 16.077 0.6 3.41 4.5 90 94 NA NA NA 4.4 92 96 16.576 1.14 3.49 4.3 96 100 17.075 0.67 3.46 4.5 98 102 NA NA NA 4.6 100 104 17.575 0.59 3.37 4.4 104 108 18.074 0.38 3.37 4.6 108 112 18.573 0.83 3.37 4.7 112 116 19.072 0.49 3.39 NA 113.5 117.5 19.258 0.56 NA NA 114.5 118.5 19.382 0 NA NA 116 120 19.568 1.3 3.44 4.4 117.5 121.5 19.753 3.51 NA NA 118.5 122.5 19.877 1.33 NA NA 120 124 20.063 0.1 3.35 4.6 124 128 20.559 0.28 3.34 4.5 128 132 21.055 0.47 3.37 4.7 132 136 21.55 0.18 3.26 4.5 136 140 22.046 0.52 3.34 NA 140 144 22.541 0.59 3.4 NA 144 148 23.037 0.89 3.34 NA 146 150 23.285 0.74 3.38 NA