Sediment Trap Data Tables
This collection of sediment trap data was compiled from a combination
of published and unpublished sources. A complete list of published sources is available
here.
Special permission
was obtained directly from the appropriate researchers to include the unpublished
data.
The online database of global sediment trap results, accessed by clicking on the 'Sediment Trap' link at left,
represents the most basic calculations and information
from the sediment trap projects that have collected particle material in
the deep ocean. When reported for multiple traps, Duration_d represents the maximum
duration of deployment (in days) for one of those traps. Similarly, the "Start Year"
indicates the earliest date from that location at which there were multiple trap
deployments. The particle mass flux has been reported to include the >1mm
size fraction and <1mm size fraction of the particulate material. The
elemental analysis is reported on the <1mm size fraction and includes
organic carbon, inorganic carbon, biogenic silicon, nitrogen and aluminum.
No dissolved portions of the sample are included, no analysis of the >1mm
size fraction is reported.
The following components are reported in a variety of units and in two separate data sets (annual and time-series): organic carbon, inorganic carbon, biogenic
silicon, nitrogen and aluminum.
The "annual flux data" contains annual integrated data from each sediment
trap in mass flux (annual flux in g m-2 yr-1; average annual flux in mg m-2
d-1) , concentration (%) and mole ratios (C-org/C-inorg, C-org/Si-bio,
Si-bio/C-inorg, C-org/N and C-org/Al).
The "time-series flux data", is the original time-series data from each sediment trap
in mass flux, (mg m-2 d-1) concentration (%), mole ratios (C-org/C-inorg,
C-org/Si-bio, Si-bio/C-inorg, C-org/N and C-org/Al) and net mass in cup
(in mg).
In some cases where published data units had to be converted for inclusion in this dataset, the following calculations were used.
Conversion factors and calculations from references
C-inorganic flux calculated from CaCO3 flux:
C-inorg. flux = CaCO3 flux / 8.33
Si-biogenic flux calculated from OPAL flux:
Si-bio. flux = OPAL (SiO2 with 10% H2O) flux / 2.4
(Ref. Mortlock and Froelich, 1989)
Si-bio. flux = OPAL (SiO2) flux / 2.14
C-organic flux calculated from Organic Matter (OM) flux:
C-org. flux = Organic Matter (OM) flux / 1.86
C-org. flux = Organic Matter (OM) flux / 2.86
C-org. flux = Organic Matter (OM) flux / 2.5
N-flux calculated from organic carbon flux and C/N mole ratio:
N-flux = C-org. flux / C-org. / N (moles)
Al-total flux calculated from Lithogenic flux:
Al flux = Lithogenic flux / 12.5
Methods
Preservatives and Poisons used:
Formaldehyde based (FORM)
Glutaraldehyde (GLUT)
Mercuric Chloride based (HgCl2)
Sodium Azide based (NaN3)
Mass Flux analysis
Particle samples were removed from the collecting cup and sieved
through a 1mm sieve. In most cases the <1mm portion was split into several
working samples.
In order to get an accurate weight of the particulate sample, the salt water
was removed by either centrifugation (CEN) or filtration (FIL).
The sample was then dried at approximately 60C, desiccated and weighed. The
net weight in the cup was then calculated for both >1mm and <1mm size
fraction.
Mass Flux Calculations:
Mass flux of the >1mm and <1mm size fraction was calculated by dividing
the net weight in the cup by the trap opening area and the collecting time. The
following equation was used:
(mass flux; mg m-2 d-1) =
(net wt. in cup; mg) / [(trap opening area; m2)*(cup collecting time; days)]
Component Mass Flux (C-org., C-inorg., Si-bio., N, and Al) calculations:
Component mass flux of C-org, C-inorg., Si-bio., N, Al was
calculated in the <1mm size fraction using the concentration of each component multiplied
by the <1mm mass flux.
(Component mass flux in mg m-2 d-1) =
(% component in <1mm/100)* (<1mm mass flux in mg m-2 d-1)
Component Mole Flux was calculated with the following equations:
C-org. mole flux in umole m-2 d-1= C-org. mass flux in mg m-2
d-1 / (12.01 / 1000)
C-inorg mol flux in umole m-2 d-1 = C-inorg mass flux in mg
m-2 d-1 / (12.01 / 1000)
Si-bio. mole flux in umole m-2 d-1 = Si-bio. mass flux in mg
m-2 d-1 / (28.09 / 1000)
N mole flux in umole m-2 d-1 = N mass flux in mg m-2 d-1 / (14.01 / 1000)
Al mole flux in umole m-2 d-1 = Al mass flux in mg m-2 d-1 / (26.98 / 1000)
Elemental analysis:
> 1mm size fraction:
The mass flux and concentration of the >1mm size fraction of the sample
is reported when available. No analysis are preformed on the >1mm size
fraction.
< 1mm size fraction:
Elemental analysis is preformed on the <1mm size fraction of the sample. After
processing of the <1mm size fraction of the sample, subsamples of the
dried <1mm size fraction sample were weighed for each analysis.
C-inorganic analysis
Weight loss analysis (%CaCO3 = %wt. loss after acid treatment): The
concentration of CaCO3 is calculated by the weight difference between weight
of the total sample and the weight of the sample after acidification. The
weight loss is assumed to be CaCO3 and inorganic carbon is calculated from
the following equation: % C-inorganic = %CaCO3/8.33
Coulometer analysis: The concentration of inorganic
Carbon (CO2) is directly quantified by coulometric titration during sample
acidification. The
inorganic carbon (C-inorg.) is calculated as a % of the analyzed sample.
Gassimetric analysis: The sample is acidified and the evolved CO2
is manometricly quantified.
The inorganic carbon (C-inorg.) is calculated as a % of the analyzed sample.
Carbon difference ( inorganic C = total C - organic C): The
concentration of inorganic carbon quantified by the difference between total
Carbon and Organic Carbon (acidified sample) as analyzed by a Carbon elemental
analyzer.
Si-biogenic analysis:
Selective Alkaline dissolution: The biogenic Si is
selectively dissolved from the sample by treating the sample with an alkaline
solution (either
Na2CO3 or NaOH) with heat for a period of time. The Si is analyzed by various
detectors, usually colorimetric spectrophotometer or by ICP-ES. The concentration
of Si in the sample is then calculated.
Total Si and Al analysis. The sample is totally dissolved by alkaline
fusion (lithium-meta borate fusion) or by acid digestion (open beaker or
sealed microwave heating). The Si and Al in the liquefied sample is analyzed
by various detectors, (ICP-ES, ICP-MS, AA). The Si and Al concentration
are then calculated. The biogenic Si is calculated by subtracting the lithogenic
Si fraction from the total Si. The lithogenic Si fraction of the sample
is calculated from the product of the Al concentration of the sample and
the Si/Al crustal ratio (Si/Al =3.4 mass).
C-organic analysis
Carbon analysis of decalcified sample: A sample is decalcified by
various acids (HCL, Sulfurous acid, Phosphoric acid) and techniques (direct
contact, fuming) and is analyzed by a carbon analyzer. The concentration
of carbon is reported as % organic carbon of the sample.
Carbon difference ( organic C = total C - inorganic C): The concentration
of organic carbon is quantified by the difference between total carbon content (carbon
elemental analyzer) and inorganic carbon content (coulometric method)
Wet Chemical carbon analysis: The organic carbon content of the
sample is extracted by chemical solutions and is determined by a carbon elemental
analyzer.
N analysis:
N in total sample: N was analyzed in the total sample with an elemental
N analyzer
N in decalcified sample: N was analyzed in a decalcified sample with
an elemental N analyzer
Al analysis:
Total Al analysis. The sample is totally dissolved by alkaline
fusion (lithium-meta borate fusion) or by acid digestion (open beaker or
sealed microwave heating). The Al in the liquefied sample is analyzed by
various detectors, (ICP-ES, ICP-MS, AA). The Al concentration as % Al in
the sample.
Average daily settling fluxes
The average daily fluxes were calculated by dividing the sum of the net
mass in each cup by the trap area multiplied by the collecting time duration
Average daily settling fluxes = Measured settling fluxes / duration (days)
Annual settling Fluxes
Annual settling fluxes = Measured settling fluxes x 365 / duration (days)