noaa-ocean-12335
Northwest Pacific RC10-196 Deglacial Biogenic Flux Data
Kohfeld, K.E.; Chase, Z.
Northwest Pacific RC10-196 Deglacial Biogenic Flux Data
2011-12-14
NCDC-Paleoclimatology
ONLINE Files
Pending
https://www.ncdc.noaa.gov/paleo/study/12335
Investigator
K.E.
Kohfeld
Investigator
Z.
Chase
earth science
paleoclimate
paleoceanography
density,dry sediment,null,gram per cubic centimeter,null,paleoceanography,null,null,N,null
earth science
paleoclimate
paleoceanography
uranium,sediment,null,parts per million,null,paleoceanography,null,null,N,null
earth science
paleoclimate
paleoceanography
organic carbon,sediment,null,gram per square centimeter per kiloyear,null,paleoceanography,null,null,N,null
earth science
paleoclimate
paleoceanography
delta 13C,Neogloboquadrina pachyderma,null,per mil,null,paleoceanography,null,null,N,null
earth science
paleoclimate
paleoceanography
age,null,null,calendar kiloyear before present,null,paleoceanography,null,null,N,null
earth science
paleoclimate
paleoceanography
biogenic silica,sediment,null,milligram per square centimeter per kiloyear,null,paleoceanography,null,null,N,null
earth science
paleoclimate
paleoceanography
calcium carbonate,sediment,null,milligram per square centimeter per kiloyear,null,paleoceanography,null,null,N,null
earth science
paleoclimate
paleoceanography
organic carbon,sediment,null,weight percent,null,paleoceanography,null,null,N,null
earth science
paleoclimate
paleoceanography
age,null,null,calendar year before present,null,paleoceanography,null,null,N,null
earth science
paleoclimate
paleoceanography
delta 18O,Neogloboquadrina pachyderma,null,per mil,null,paleoceanography,null,null,N,null
earth science
paleoclimate
paleoceanography
232Th,sediment,unspecified margin of error,disintegration per minute per gram,null,paleoceanography,null,null,N,null
earth science
paleoclimate
paleoceanography
230Th,sediment,unspecified margin of error,disintegration per minute per gram,null,paleoceanography,null,null,N,null
earth science
paleoclimate
paleoceanography
230Th,sediment,null,disintegration per minute per gram,null,paleoceanography,null,null,N,null
earth science
paleoclimate
paleoceanography
calcium carbonate,sediment,null,weight percent,null,paleoceanography,null,null,N,null
earth science
paleoclimate
paleoceanography
238U,sediment,unspecified margin of error,disintegration per minute per gram,null,paleoceanography,null,null,N,null
earth science
paleoclimate
paleoceanography
sedimentation rate,null,null,centimeter per kiloyear,null,paleoceanography,null,null,N,null
earth science
paleoclimate
paleoceanography
biogenic silica,sediment,null,weight percent,null,paleoceanography,null,null,N,null
earth science
paleoclimate
paleoceanography
depth,null,null,centimeter,null,paleoceanography,null,null,N,null
earth science
paleoclimate
paleoceanography
232Th,sediment,null,disintegration per minute per gram,null,paleoceanography,null,null,N,null
earth science
paleoclimate
paleoceanography
238U,sediment,null,disintegration per minute per gram,null,paleoceanography,null,null,N,null
earth science
paleoclimate
paleocean
geochemistry
earth science
paleoclimate
paleocean
oxygen isotopes
geoscientificInformation
biogeochemical cycles
92880 cal yr BP
9232 cal yr BP
Complete
54.7
54.7
177.1
177.1
-1007
-1007
Ocean
Pacific Ocean
North Pacific Ocean
RC10-196>LATITUDE 54.7>LONGITUDE 177.1
None
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English
DOC/NOAA/NESDIS/NCEI
National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce
https://www.ncdc.noaa.gov/data-access/paleoclimatology-data
DATA Center Contact
Bruce
Bauer
bruce.a.bauer@noaa.gov
paleo@noaa.gov
303-497-6280
303-497-6513
325 Broadway, E/NE31
Boulder
CO
80305-3328
USA
online
ASCII
Kohfeld, K.E. and Z. Chase. 2011.
Controls on Deglacial Changes in Biogenic Fluxes
in the North Pacific Ocean.
Quaternary Science Reviews, Vol. 30, Issues 23-24,
pp. 3350-3363, November 2011.
doi:10.1016/j.quascirev.2011.08.007.
The subarctic North Pacific Ocean holds a large CO2 reservoir that
is currently isolated from the atmosphere by a low-salinity layer.
It has recently been hypothesized that the reorganization of these
high-CO2 waters may have played a crucial role in the degassing of
carbon dioxide to the atmosphere during the last deglaciation.
This reorganization would leave some imprint on paleo-productivity
records. Here we present 230Th-normalized biogenic fluxes from an
intermediate depth sediment core in the Northwest Pacific (RC10-196,
54.7°N, 177.1°E, 1007 m) and place them within the context of a
synthesis of previously-published biogenic flux data from 49
deep-sea cores north of 20°N, ranging from 420 to 3968 m water depth.
The 230Th-normalized opal, carbonate, and organic carbon fluxes
from RC10-196 peak approximately 13,000 calendar years BP during
the Bølling/Allerød (B/A) period. Our data synthesis suggests that
biogenic fluxes were in general lowest during the last glacial
period, increased somewhat in the Northwest Pacific during Heinrich
Event 1, and reached a maximum across the entire North Pacific
during the B/A period. We evaluate several mechanisms as possible
drivers of deglacial change in biogenic fluxes in the North Pacific,
including changes in preservation, sediment focusing, sea ice extent,
iron inputs, stratification, and circulation shifts initiated in the
North Atlantic and North Pacific. Our analysis suggests that while
micronutrient sources likely contributed to some of the observed
changes, the heterogeneity in timing of glaciogenic retreat
and sea level make these mechanisms unlikely causes of region-wide
contemporaneous peaks in export production. We argue that
paleo-observations are most consistent with ventilation increases
in both the North Pacific (during H1) and North Atlantic (during B/A)
being the primary drivers of increases in biogenic flux during
the deglaciation, as respectively they were likely to bring
nutrients to the surface via increased vertical mixing
and shoaling of the global thermocline.
STUDY NOTES: We present 230Th-normalized biogenic fluxes from an intermediate
depth sediment core in the Northwest Pacific (RC10-196) and place
them within the context of a synthesis of previously-published
biogenic flux data from 49 deep-sea cores north of 20ºN,
ranging from 420 to 3968 m water depth. The 230Th normalized opal,
carbonate, and organic carbon fluxes from RC10-196 peak
approximately 13,000 calendar years BP during the Bølling/Allerød
(B/A) period. This file includes:
(a) radiocarbon data from N. pachyderma (s),
(b) oxygen and carbon isotope data on N. pachyderma (s),
(c) wt% and mass accumulation rates of opal, carbonate,
organic carbon, and authigenic Uranium, and
(d) associated 230Th data.
Note that MARtoc, MARcaco3, and MARopal (mg/cm2/y) are not 230Th fluxes,
but are estimated as: MAR = f * LSR * DBD (where DBD = dry bulk density;
LSR = linear sedimentation rate; f = measured fraction of TOC, CaCO3,
and opal, respectively.)
Methods:
230Th-normalization was used to reconstruct particle flux to an
intermediate depth sediment core, RC10-196. An age model was
determined using a combination of radiocarbon dates and oxygen
isotope stratigraphy. Oxygen isotope values were measured on
N. pachyderma (sinistral coiling) from the 150-250 um size
fraction at the Saskatchewan Isotope Laboratory at the University
of Saskatchewan. Radiocarbon analysis was conducted on three samples
(two of N. pachyderma (sinistral coiling), one of mixed planktonic
foraminifera), at Lawrence Livermore National Laboratory.
These dates were converted to calendar age using the CALIB program
(Stuiver and Reimer, 1993 (version 6.0)). Prior to calibration,
a reservoir correction of 450 years was applied, using estimates
obtained by Sarnthein et al. (2007) on cores from the NW Pacific
region. Using this age model, sedimentation rates at RC10-196
ranged from 4.2 to 5.9 cm/ka over the last 30,000 years.
Samples for U-series measurement were spiked with yield tracers
(229Th and 236U), digested in HCl, HF, HNO3 and perchloric acid
(Fleisher and Anderson, 1991) and pre-concentration by anion
exchange resin (Chase et al., 2003). Isotope spikes were
calibrated against a natural U standard (CRM-145) and a natural
Th standard (NIST 3159). Digests were analyzed by isotope dilution
HR-ICP-MS (Axiom) at Oregon State University (Chase et al., 2003;
Fleisher and Anderson, 2003). Mass bias was assessed by repeated
analysis of CRM-145. Propagated uncertainties for individual
analyses were ~ 4% for 230Th concentration while repeated
digestion and analysis of an in-house sediment standard was
reproducible to 6%. Excess 230Th and authigenic U were calculated
from the sediment concentration data assuming a detrital U/Th ratio
of 0.7 ± 0.1 (Henderson and Anderson, 2003). Thorium concentrations
measured in the GEOTRACES intercalibration sediment sample were
in agreement with the main distribution of the submitted data
(Anderson et al., submitted manuscript).
GET DATA
https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/kohfeld2011/kohfeld2011.txt
GET DATA
https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/kohfeld2011/kohfeld2011.xls
USA/NOAA
DIF
Version 9.8.4
2018-12-11
2018-12-11