102
Land-Ocean Systems in the Siberian Arctic: Dynamics and History
(Pfirman et al. 1990; Niirnberg et aI., 1994; Eicken et al. 1996; Lindemann et aI., this volume,
Golovin et aI., this volume). First estimations give export sediment rates of 4 x 106 t yr-]
(Eicken et aI., 1996). The off-shelf transport of ice-rafted sediments (IRS) mainly depends on
the initial ice formation and sediment entrainment in shallow water during fall freeze-up, the ice
growth regime in the flaw lead during the course of the winter and the volume of ice exported
beyond the limit of the minimum summer ice extent (Eicken et aI., 1996).
The Russian-German Transdrift III expedition into the Laptev Sea that was carried out during
the fall freeze-up in 1995 provided the opportunity to study the initial phase of ice formation in
the Laptev Sea.
Sea ice formation off the Lena delta started in early-October 1995. The median content of
particles in ice measured in this region was 148.9 mg/l (Lindemann et aI., this volume).
Compared to the suspended matter concentration in the underlying water column this is a more
than 20 fold enrichment of particles in the newly formed ice (Lindemann et aI., this volume).
Our primary purpose was (1) to assess heavy metal contamination levels in new ice (2) to
advance our understanding of trace element cycling connected to the formation of new ice (3) to
provide information about the value of trace elements in Arctic Sea ice as a source-area tracer
for the reconstruction of ice drift patterns.
Material and methods
Sampling was carried out in different ways, depending on the type of ice. Thin surface ice like
pancake ice, dark nil as, slush and grease ice were sampled with a net from the bow of the
ships. Surface ice of more than 1 cm but less than 20 cm thickness was sampled using a diving
platform. Samples of thin ice were taken with the help of Teflon-chisel, plastic scoop and cash.
All samples were melted on board in a clean air cabinet (class 100) in polystyren boxes. Prior to
sampling the boxes were rinsed with ultrapure water and leached with diluted HCI for two
days.
Surface ice with more than 20 cm thickness was sampled tens off the windward side of the
ship meters off the ship with ice coring devices made of plastic and stainless steel. To avoid
contamination, the outer layer of the ice core was removed with a ceramic knife. The cleaned
cores were stored and allowed to melt in cleaned polystyrene boxes before filtration.
Nirogen pressure filtration was carried out in a clean air cabinet on board Kapitan Dranitzyn.
For the determination of particulate trace elements we used 0.4 I-Lm pre-cleaned polycarbonate
filters (leached 3 times for 6 hours in 3% subboiled HCI at 60° C temperature). The filtrate was
acidified to pH 2 and stored in acid cleaned polyethylene bottles.
Final analysis was performed in the Research Center Geesthacht including salt-matrix
separation and pre-concentration of the water samples followed by analysis with total reflection
X-ray fluorescence (TXRF), a modified procedure of the conventional energy dispersive XRF
(Prange, 1983). Coupled plasma mass spectrometry (ICP-MS) completed the investigations.
All analytical procedures in Geesthacht were carried out in clean rooms (class 1000).
Elements in sea water measured by TXRF include V, Mn, Fe, Ni, Cu, Zn, Se, Mo, Cd, U
and Pb.
About 30 particle bound elements including heavy metals and the REE were measured in seaice by means of TXRF and ICP-MS. For the digestion procedure filters were transferred to
Teflon vessels and 4 ml HN03, 0,5 ml H20 2 ,1 ml HF and an internal standard (Ga) were
added. After running a temperature program (stepwise escalation from 200 W to 800 W) for 20
minutes samples were evaporated to dryness. After 2 ml HCL were added the sample was
heated again.
The accuracy and precision of our analytical methods for the determination of dissolved
Land-Ocean Systems in the Siberian Arctic: Dynamics and History
(Pfirman et al. 1990; Niirnberg et aI., 1994; Eicken et al. 1996; Lindemann et aI., this volume,
Golovin et aI., this volume). First estimations give export sediment rates of 4 x 106 t yr-]
(Eicken et aI., 1996). The off-shelf transport of ice-rafted sediments (IRS) mainly depends on
the initial ice formation and sediment entrainment in shallow water during fall freeze-up, the ice
growth regime in the flaw lead during the course of the winter and the volume of ice exported
beyond the limit of the minimum summer ice extent (Eicken et aI., 1996).
The Russian-German Transdrift III expedition into the Laptev Sea that was carried out during
the fall freeze-up in 1995 provided the opportunity to study the initial phase of ice formation in
the Laptev Sea.
Sea ice formation off the Lena delta started in early-October 1995. The median content of
particles in ice measured in this region was 148.9 mg/l (Lindemann et aI., this volume).
Compared to the suspended matter concentration in the underlying water column this is a more
than 20 fold enrichment of particles in the newly formed ice (Lindemann et aI., this volume).
Our primary purpose was (1) to assess heavy metal contamination levels in new ice (2) to
advance our understanding of trace element cycling connected to the formation of new ice (3) to
provide information about the value of trace elements in Arctic Sea ice as a source-area tracer
for the reconstruction of ice drift patterns.
Material and methods
Sampling was carried out in different ways, depending on the type of ice. Thin surface ice like
pancake ice, dark nil as, slush and grease ice were sampled with a net from the bow of the
ships. Surface ice of more than 1 cm but less than 20 cm thickness was sampled using a diving
platform. Samples of thin ice were taken with the help of Teflon-chisel, plastic scoop and cash.
All samples were melted on board in a clean air cabinet (class 100) in polystyren boxes. Prior to
sampling the boxes were rinsed with ultrapure water and leached with diluted HCI for two
days.
Surface ice with more than 20 cm thickness was sampled tens off the windward side of the
ship meters off the ship with ice coring devices made of plastic and stainless steel. To avoid
contamination, the outer layer of the ice core was removed with a ceramic knife. The cleaned
cores were stored and allowed to melt in cleaned polystyrene boxes before filtration.
Nirogen pressure filtration was carried out in a clean air cabinet on board Kapitan Dranitzyn.
For the determination of particulate trace elements we used 0.4 I-Lm pre-cleaned polycarbonate
filters (leached 3 times for 6 hours in 3% subboiled HCI at 60° C temperature). The filtrate was
acidified to pH 2 and stored in acid cleaned polyethylene bottles.
Final analysis was performed in the Research Center Geesthacht including salt-matrix
separation and pre-concentration of the water samples followed by analysis with total reflection
X-ray fluorescence (TXRF), a modified procedure of the conventional energy dispersive XRF
(Prange, 1983). Coupled plasma mass spectrometry (ICP-MS) completed the investigations.
All analytical procedures in Geesthacht were carried out in clean rooms (class 1000).
Elements in sea water measured by TXRF include V, Mn, Fe, Ni, Cu, Zn, Se, Mo, Cd, U
and Pb.
About 30 particle bound elements including heavy metals and the REE were measured in seaice by means of TXRF and ICP-MS. For the digestion procedure filters were transferred to
Teflon vessels and 4 ml HN03, 0,5 ml H20 2 ,1 ml HF and an internal standard (Ga) were
added. After running a temperature program (stepwise escalation from 200 W to 800 W) for 20
minutes samples were evaporated to dryness. After 2 ml HCL were added the sample was
heated again.
The accuracy and precision of our analytical methods for the determination of dissolved