Particle Entrainment into Newly Forming Sea Ice - Freeze-Up
Studies in October 1995
F. Lindemann!, J.A. HOIemann!, A. Korablev 2 and A. Zachek 2
(I) GEOMAR Forschungszentrumfiir marine Geowissenschaften, Wischhofstrasse 1-3, D 24148 Kie/,
Germany
(2) State Research Center - Arctic and Antarctic Research Institute, 38 Bering St., 199226 SI. Petersburg,
Russia
Recei ved 14 February 1997 and accepted in revised form 17 October 1997
Abstract - Particulate matter of lithogenic and biogenic origin is often highly enriched in
Arctic sea ice. Entrainment of particles is most effective during fall freeze-up over shallow
Arctic shelves.
Particle entrainment into newly forming sea ice was investigated during the Transdrift III
expedition in October 1995, conducted in the Laptev Sea, Siberian Arctic. Considering the
prevailing calm meteorological conditions, processes related to propagating wave fields are
identified as possible mechanisms for particle entrainment into the forming sea ice, where
particles were significantly enriched as compared to the underlying water column.
Due to high drift velocities and a loose ice cover during the observed freeze-up, sediment
export by sea ice from near-shore areas towards the deep basins of the Arctic Ocean was
likely.
Introduction
Coastal waters of the Arctic marginal seas are covered by sea ice for more than six months a
year. Therefore, classical erosion processes like resuspension of bottom sediments due to
storm-induced waves during winter times are mostly prevented. It is assumed that sea ice
related processes act as an important factor influencing the sediment regime. For example,
regression of shallow seas due to tectonic uplifts or eustatic sea level changes. The withdrawal
causes a steepening of the shelf gradient. In order to reestablish the shelf-gradient equilibriuim,
sediment erosion in near-shore areas, and sediment deposition further off shore is required.
Sediment-laden sea ice can transport sediments from coastal areas across the shelves towards
the deep ocean basins, and thus, influencing the overall sediment budget in northern polar
regions (Kempema et aI., 1989). Sea-ice sediments decrease the albedo when accumulating on
the ice surface and therefore accelerate ice melting (Reimnitz and Bruder, 1972; Barnes et aI.,
1982). Hazardous substances, e.g. heavy metals and persistent organic substances, might be
associated with particles. If these particles are incorporated into sea ice, the hazardous
substances could be transported over wide areas. Due to ice melting in marginal ice zones, e.g.
off eastern Greenland, these substances are released into the water column, where they might
enter the food web (Pfirman et aI., 1995).
During the last decades, considerable work has been done on particle entrainment into sea ice.
Biologists and geologists discuss how lithogenic and bogenic particles are entrained into sea ice
(Campbell and Collin, 1958; Reimnitz and Bruder, 1972; Barnes et aI., 1982; Weeks and
Ackley, 1982; Osterkamp and Gosink, 1984; Kempema et aI., 1986; Ackley et aI., 1987;
Ackermann et aI., 1990; Shen and Ackermann, 1990; Reimnitz et aI., 1992; Dethleff, 1995). It
is assumed that most of the particles are entrained when sea ice is forming in autumn or
beginning winter (Medcov and Thomas, 1974; Barnes et aI., 1982; Osterkamp and Gosink,
1984). Previous field work concerning particle entrainment into sea ice during freeze-up in
autumn was conducted in the Beaufort Sea and the Antarctic (Reimnitz and Dunton, 1979;
Ackley et aI., 1987; Reimnitz and Kempema, 1987; Reimnitz et aI., 1987; Kempema et aI.,
In: Kasscns, H., H.A. Bauch, I. Dmitrenko, H. Bicken, H.-W. Hubberten, M. Melles, 1. Thiede and L. Timokhov (eds.)
Land-Ocean Systems in the Siberian Arctic: Dynamics and History. Springer-Verlag, Berlin, 1999. 113-123.
Studies in October 1995
F. Lindemann!, J.A. HOIemann!, A. Korablev 2 and A. Zachek 2
(I) GEOMAR Forschungszentrumfiir marine Geowissenschaften, Wischhofstrasse 1-3, D 24148 Kie/,
Germany
(2) State Research Center - Arctic and Antarctic Research Institute, 38 Bering St., 199226 SI. Petersburg,
Russia
Recei ved 14 February 1997 and accepted in revised form 17 October 1997
Abstract - Particulate matter of lithogenic and biogenic origin is often highly enriched in
Arctic sea ice. Entrainment of particles is most effective during fall freeze-up over shallow
Arctic shelves.
Particle entrainment into newly forming sea ice was investigated during the Transdrift III
expedition in October 1995, conducted in the Laptev Sea, Siberian Arctic. Considering the
prevailing calm meteorological conditions, processes related to propagating wave fields are
identified as possible mechanisms for particle entrainment into the forming sea ice, where
particles were significantly enriched as compared to the underlying water column.
Due to high drift velocities and a loose ice cover during the observed freeze-up, sediment
export by sea ice from near-shore areas towards the deep basins of the Arctic Ocean was
likely.
Introduction
Coastal waters of the Arctic marginal seas are covered by sea ice for more than six months a
year. Therefore, classical erosion processes like resuspension of bottom sediments due to
storm-induced waves during winter times are mostly prevented. It is assumed that sea ice
related processes act as an important factor influencing the sediment regime. For example,
regression of shallow seas due to tectonic uplifts or eustatic sea level changes. The withdrawal
causes a steepening of the shelf gradient. In order to reestablish the shelf-gradient equilibriuim,
sediment erosion in near-shore areas, and sediment deposition further off shore is required.
Sediment-laden sea ice can transport sediments from coastal areas across the shelves towards
the deep ocean basins, and thus, influencing the overall sediment budget in northern polar
regions (Kempema et aI., 1989). Sea-ice sediments decrease the albedo when accumulating on
the ice surface and therefore accelerate ice melting (Reimnitz and Bruder, 1972; Barnes et aI.,
1982). Hazardous substances, e.g. heavy metals and persistent organic substances, might be
associated with particles. If these particles are incorporated into sea ice, the hazardous
substances could be transported over wide areas. Due to ice melting in marginal ice zones, e.g.
off eastern Greenland, these substances are released into the water column, where they might
enter the food web (Pfirman et aI., 1995).
During the last decades, considerable work has been done on particle entrainment into sea ice.
Biologists and geologists discuss how lithogenic and bogenic particles are entrained into sea ice
(Campbell and Collin, 1958; Reimnitz and Bruder, 1972; Barnes et aI., 1982; Weeks and
Ackley, 1982; Osterkamp and Gosink, 1984; Kempema et aI., 1986; Ackley et aI., 1987;
Ackermann et aI., 1990; Shen and Ackermann, 1990; Reimnitz et aI., 1992; Dethleff, 1995). It
is assumed that most of the particles are entrained when sea ice is forming in autumn or
beginning winter (Medcov and Thomas, 1974; Barnes et aI., 1982; Osterkamp and Gosink,
1984). Previous field work concerning particle entrainment into sea ice during freeze-up in
autumn was conducted in the Beaufort Sea and the Antarctic (Reimnitz and Dunton, 1979;
Ackley et aI., 1987; Reimnitz and Kempema, 1987; Reimnitz et aI., 1987; Kempema et aI.,
In: Kasscns, H., H.A. Bauch, I. Dmitrenko, H. Bicken, H.-W. Hubberten, M. Melles, 1. Thiede and L. Timokhov (eds.)
Land-Ocean Systems in the Siberian Arctic: Dynamics and History. Springer-Verlag, Berlin, 1999. 113-123.