[Parameters: Topic='PALEOCLIMATE', Term='LAND RECORDS', Variable_Level_1='PALEOSOLS']
DIRTMAP Version 2. Last Glacial Maximum, Late Holocene, and Modern Eolian Fluxes from Ice Cores, Marine Sediments, Marine Sediment Traps, and Terrestrial DepositsEntry ID: NOAA_NCDC_PALEO_2002-045
Abstract: The records of dust accumulation rates included here represent the second
version of the DIRTMAP data base, including dust information from ice cores,
marine sediments, marine sediment traps, and loess sediments. Mass
accumulation rates are estimated in g/m2/yr, and a LGM/Holocene ratio are
provided where possible. All data were compiled from the literature.
In addition to containing more ... sites than version 1.0 (including data from some
terrestrial deposits), DIRTMAP version 2.0 also contains information on site
age models (e.g. layer counting, radiocarbon, oxygen isotope stratigraphy), the
time interval over which accumulation rates were averaged, the type of
information used to calculate an aeolian accumulation rate (e.g. isolation of
terrigenous components, Al concentration measurements, number or mass
concentrations). This data set also contains (in a separate table) estimates
of non-carbonate accumulation rates in marine sediments [Catubig et al.,
1998], which can in some cases be used as a first order estimate of dust
accumulation rates (e.g., in regions with low opal and organic carbon rates).
In version 2.0, all marine sediment data have also been screened to indicate
where contamination problems (e.g. regions with ice-rafted detritus, fluvial
input, lateral sediment redistribution). Potentially contaminated sites are
still included in the data set but are flagged. It is important to make sure
that all flagged sites are removed from the data set before data are compared
directly with simulated dust accumulation rates.
Ice core data are the same as presented in DIRTMAP version 1.0. We assume that
all the methods used to calculate the eolian concentrations yield broadly
comparable results, although there are differences in calculated ratios
depending on whether mass- or number-based concentrations are used. Ice core
dust deposition is expressed here as deposition fluxes and not dust
concentration in the ice core, to ensure consistency with the marine sediment
data. The disadvantage of converting ice core data from concentration to
fluxes is that this calculation relies upon estimated ice accumulation rates.
LGM/current ratios also represent changes in dust deposition fluxes and not in
dust concentrations. (Dust deposition fluxes are the dust concentrations times
the ice accumulation rate.) In the ice core studies where only particle number
concentrations were reported, only the ratio between LGM and current is shown
because it is not straightforward to convert from number concentration to mass
concentration. In two cases, the LGM/current concentration ratio is estimated
from a reported figure [Hammer et al., 1985; Thompson et al., 1989; Thompson
et al., 1995], while otherwise, the reported values are shown. The time
intervals compared may vary between the different locations due to variations
The LGM value is either the mean of the interval 15-30 kyr B.P. or the mean of
samples from a shorter period within that interval. The current value is the
mean for the Holocene (0-10 kyr B.P.) or the mean of samples from a shorter
period within that interval.
Sediment trap eolian deposition rates (Table 3) were estimated in one of the
(a) from Al concentration data assuming terrigenous material is 8% Al
(e.g. [Kawahata and Ohta, 2000]
(b) particle number estimates, converted to mass using a particle density of
2.8 g/cm3 (e.g. [Clemens, 1998], or
(c) by eliminating organic carbon, carbonate, and opal from total particles, a
general procedure which is described in[Honjo et al., 1982]. In this last case,
lithogenic fluxes in sediment traps are estimated according to [Wefer and
Lithogenic flux = Total flux (opal flux + carbonate flux + [2*organic carbon
Eolian accumulation rates (MAReol) for marine sediments (Table 2) are generally
MAReol (g/m2/yr) = LSR (m/yr) x BD (g/m3) x f
where LSR is linear sedimentation rate, BD is sediment bulk density (standard
error = +/-10-25%),
and f is the measured eolian fraction of the sediment sample (standard error =
Information on sediment age models, and the time period over which accumulation
rates were estimated, are included in Table 2.
Also included in this compilation are non-carbonate accumulation rates (Table
5) taken from Catubig et al. (1998). These data screened for possible
contamination by ice rafted detritus, sediment redistribution, and fluvial
input (see notes about data flags under Data Codes).
DIRTMAP version 2.0 also contains some information from terrestrial deposits,
from North America, New Zealand, Europe, and East Asia. Age models were based
on radiocarbon dates, luminescence dates, and stratigraphic correlation to the
marine oxygen isotope stratigraphy. Accumulation rates represent broad
averages for Marine Isotope Stage 1 (0-12 ka) and Stage 2 (12-24 ka). In all
instances, loess sediments were assumed to be 100% eolian.
Version 1.0 of DIRTMAP is also available:
Data Set Citation
Dataset Originator/Creator: Karen E. Kohfeld
Dataset Title: DIRTMAP Version 2. LGM and Late Holocene Eolian Fluxes from Ice Cores, Marine Sediment Traps, Marine Sediments, and Loess Deposits
Dataset Series Name: IGBP PAGES/WDCA CONTRIBUTION SERIES NUMBER: 2002-045
Dataset Release Date: July 2002
Dataset Release Place: Boulder, CO
Dataset Publisher: IGBP PAGES/World Data Center for Paleoclimatology
Version: Version 2
Issue Identification: 2002-045
Other Citation Details: NOAA/NCDC Paleoclimatology ProgramOnline Resource: ftp://ftp.ncdc.noaa.gov/pub/data/paleo/loess/dirtmap/version2/
Start Date: 1980-01-01Stop Date: 1996-12-31
Paleo Temporal Coverage
Paleo Start Date: 10000 ybp
Paleo Stop Date: 0 ybp
OCEANS > MARINE SEDIMENTS > GEOTECHNICAL PROPERTIES
OCEANS > MARINE SEDIMENTS > STRATIGRAPHIC SEQUENCE
OCEANS > MARINE SEDIMENTS > TERRIGENOUS SEDIMENTS
PALEOCLIMATE > ICE CORE RECORDS > PARTICULATE MATTER
PALEOCLIMATE > ICE CORE RECORDS > VOLCANIC DEPOSITS
PALEOCLIMATE > LAND RECORDS > GLACIATION
PALEOCLIMATE > LAND RECORDS > LOESS
PALEOCLIMATE > LAND RECORDS > PALEOSOLS
PALEOCLIMATE > LAND RECORDS > RADIOCARBON
PALEOCLIMATE > LAND RECORDS > SEDIMENTS
PALEOCLIMATE > LAND RECORDS > STRATIGRAPHIC SEQUENCE
PALEOCLIMATE > LAND RECORDS > VOLCANIC DEPOSITS
PALEOCLIMATE > OCEAN/LAKE RECORDS > RADIOCARBON
PALEOCLIMATE > OCEAN/LAKE RECORDS > SEDIMENTS
PALEOCLIMATE > OCEAN/LAKE RECORDS > STRATIGRAPHIC SEQUENCE
Data Set Progress
Distribution Media: online ftp
Distribution Format: ascii, excel spreadsheets
Email: kek at bgc-jena.mpg.de
Catubig, N.R., D.E. Archer, R. Francois, P. deMenocal, W. Howard, and E.-F. Yu, Global deep-sea burial rate of calcium carbonate during the last glacial maximum, Paleoceanography, 13 (3), 298-310, 1998.
Clemens, S.C., Dust response to seasonal atmospheric forcing: Proxy evaluation and calibration, Paleoceanography, 13 (5), 471-490, 1998.
Hammer, C.U., H.B. Clausen, W. Dansgaard, A. Neftel, P. Kristinsdottor, and E. Johnson, Continuous impurity analysis along the Dye 3 deep core, in Greenland
Ice Core: Geophysics, Geochemistry, and the Environment, edited by C. Langway Jr., H. Oeschger, and W. Dansgaard, pp. 90-94, AGU, Washington DC, 1985.
Honjo, S., S.J. Manganini, and L.J. Poppe, Sedimentation of lithogenic
particles in the open sea, Marine Geology, 50, 199-220, 1982.
Kawahata, H., and H. Ohta, Sinking and suspended particles in the South-west Pacific, Marine Freshwater Research, 51, 113-126, 2000.
Thompson, L.G., E. Mosley-Thompson, M.E. Davis, J.F. Bolzan, J. Dai, T. Yao, N. Gundestrup, X. Wu, L. Klein, and Z. Xie, Holocene-late Pleistocene climatic ice core records from Qinghai-Tibetan plateau, Science, 246, 474-477, 1989.
Thompson, L.G., E. Mosley-Thompson, M.E. Davis, P.-N. Lin, K.A. Henderson, J. Cole-Dai, J.F. Bolzan, and K.-b. Liu, Late Glacial Stage and Holocene
tropical ice core records from Huascaràn, Peru, Science, 269, 46-50, 1995.
Wefer, G., and G. Fischer, Seasonal patterns of vertical particle flux in
equatorial and coastal upwelling areas of the eastern Atlantic, Deep-Sea
Research, 40 (8), 1613-1645, 1993.
for an extensive list of references.
Extended Metadata Properties
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Creation and Review Dates
DIF Creation Date: 2006-08-31
Last DIF Revision Date: 2006-08-31