Dissolved Oxygen, Silicon, Phosphorous and Suspended Matter
Concentrations During the Spring Breakup of the Lena River
S.V. Pivovarov 1 , J.A. HOIemann 2 , H. Kassens 2 , M. Antonow 3 and I. Dmitrenko 1
(1) State Research Center - Arctic and Antarctic Research Institute. 38 Bering St .. 199226 St. Petersburg.
Russia
(2) GEOMAR Forschungszentrumfur marine Geowissenschaften. Wischhof~trasse /-3. D 24148 Kie/.
Germany
(3) TV Bergakademie Freiberg. Institut fur Geologie. Bernhard-von-Cotta-Str. 2. D 09596 Freiherg. Germany
Received 11 March 1997 and accepted in revised form 3 March 1998
Abstract - In spring of 1996 hydrochemical and sedimentological measurements were
carried out in the Lena river and along transects in the SE Laptev Sea off the delta. The
investigations were conducted during the season of the spring thaw in which the freshwater
discharge of the Lena river increases dramatically and the ice on the river breaks up.
River water during the low discharge winter period showed high concentrations of silicon
but low concentrations of oxygen and suspended matter. During the first phase of the spring
breakup this high-silicon winter water was flushed from the river into the Laptev Sea. This
is reflected by elevated silicon concentrations in the water column off the Lena delta. In the
course of the breakup. the silicon concentration in the river water and the low salinity
freshwater layer off the delta decreased. while the turbidity increased significantly.
The strong inflow of river water was also reflected by a steadily thickening freshwater layer
that formed in the SE Laptev Sea off the Lena delta. This turbid water mass was separated
hy a strong pycnocline from the underlying. less turbid brackish water. This phenomenon
suggests that during the breakup period riverine suspended matter is laterally advectcd above
the pycnoline far into the SE Laptev Sea.
Introduction
Five large Siberian rivers yearly discharge 714 km 3 of fresh water to the Laptev Sea. Almost
505 km 3 come from the Lena river, one of the largest river systems on earth with a drainage
area of 2.46 x 10 6 km 2 . At the river mouth, the Lena forms an extensive delta covering an area
of 32000 km 2 crossed by many distributaries (Figure I). The largest distributaries are the
Trofimovskaya (61.5 % of the total Lena river discharge), the Bykovskaya (25.3 %), the
Olenekskaya (6.8 %) and the Tumatskaya distributary (6.4 %) (Ivanov and Piskun, 1995).
Freshwater discharge from the Lena is highly variable throughout the year. During winter the
discharge can be as low as 366 m 3 /s ( April 27, 1940 observed near the Kyusyur station). The
highest water discharge ever observed occurred in the spring of 1944 (194000 m 3 /s on June
11). Thus, the peak draining can be 500 times higher than the discharge during winter. This is
accompanied by a ten to twentyfold increase in suspended particulate matter (SPM)
concentration (Cauwet and Sidorov, 1996). Russian data indicate that, in June alone, about 200
km3 of fresh water and more than 10 million tons of SPM flow into the Laptev Sea (Ivanov and
Piskun, 1995).
Despite of the fact that the river breakup in spring is obviously the most important period of
the hydrologic cycle of Siberian rivers, it is also the least investigated period. Only few
investigations in Siberia were carried out during the spring thaw (Tasakov, 1955; Antonov,
1967; Ivanov and Nalimov, 1981; Nalimov, 1995). Usually these investigations comprise
visual observations of ice conditions. A more detailed description of breakup processes in
Arctic rivers was carried out in the delta of the Colville river in Alaska (Hamilton et aI., 1974;
Walker, 1973).
In: Kassens. H .. H.A. Bauch. I. Dmitrenko. H. Eicken. H.-W. Hubberten. M. Melles. J. Thiede and L. Timokhov (eds.)
Land-Ocean Systems in the Siberian Arctic: Dynamics and History. Springer-Verlag. Berlin. 1999. 251-264.
Concentrations During the Spring Breakup of the Lena River
S.V. Pivovarov 1 , J.A. HOIemann 2 , H. Kassens 2 , M. Antonow 3 and I. Dmitrenko 1
(1) State Research Center - Arctic and Antarctic Research Institute. 38 Bering St .. 199226 St. Petersburg.
Russia
(2) GEOMAR Forschungszentrumfur marine Geowissenschaften. Wischhof~trasse /-3. D 24148 Kie/.
Germany
(3) TV Bergakademie Freiberg. Institut fur Geologie. Bernhard-von-Cotta-Str. 2. D 09596 Freiherg. Germany
Received 11 March 1997 and accepted in revised form 3 March 1998
Abstract - In spring of 1996 hydrochemical and sedimentological measurements were
carried out in the Lena river and along transects in the SE Laptev Sea off the delta. The
investigations were conducted during the season of the spring thaw in which the freshwater
discharge of the Lena river increases dramatically and the ice on the river breaks up.
River water during the low discharge winter period showed high concentrations of silicon
but low concentrations of oxygen and suspended matter. During the first phase of the spring
breakup this high-silicon winter water was flushed from the river into the Laptev Sea. This
is reflected by elevated silicon concentrations in the water column off the Lena delta. In the
course of the breakup. the silicon concentration in the river water and the low salinity
freshwater layer off the delta decreased. while the turbidity increased significantly.
The strong inflow of river water was also reflected by a steadily thickening freshwater layer
that formed in the SE Laptev Sea off the Lena delta. This turbid water mass was separated
hy a strong pycnocline from the underlying. less turbid brackish water. This phenomenon
suggests that during the breakup period riverine suspended matter is laterally advectcd above
the pycnoline far into the SE Laptev Sea.
Introduction
Five large Siberian rivers yearly discharge 714 km 3 of fresh water to the Laptev Sea. Almost
505 km 3 come from the Lena river, one of the largest river systems on earth with a drainage
area of 2.46 x 10 6 km 2 . At the river mouth, the Lena forms an extensive delta covering an area
of 32000 km 2 crossed by many distributaries (Figure I). The largest distributaries are the
Trofimovskaya (61.5 % of the total Lena river discharge), the Bykovskaya (25.3 %), the
Olenekskaya (6.8 %) and the Tumatskaya distributary (6.4 %) (Ivanov and Piskun, 1995).
Freshwater discharge from the Lena is highly variable throughout the year. During winter the
discharge can be as low as 366 m 3 /s ( April 27, 1940 observed near the Kyusyur station). The
highest water discharge ever observed occurred in the spring of 1944 (194000 m 3 /s on June
11). Thus, the peak draining can be 500 times higher than the discharge during winter. This is
accompanied by a ten to twentyfold increase in suspended particulate matter (SPM)
concentration (Cauwet and Sidorov, 1996). Russian data indicate that, in June alone, about 200
km3 of fresh water and more than 10 million tons of SPM flow into the Laptev Sea (Ivanov and
Piskun, 1995).
Despite of the fact that the river breakup in spring is obviously the most important period of
the hydrologic cycle of Siberian rivers, it is also the least investigated period. Only few
investigations in Siberia were carried out during the spring thaw (Tasakov, 1955; Antonov,
1967; Ivanov and Nalimov, 1981; Nalimov, 1995). Usually these investigations comprise
visual observations of ice conditions. A more detailed description of breakup processes in
Arctic rivers was carried out in the delta of the Colville river in Alaska (Hamilton et aI., 1974;
Walker, 1973).
In: Kassens. H .. H.A. Bauch. I. Dmitrenko. H. Eicken. H.-W. Hubberten. M. Melles. J. Thiede and L. Timokhov (eds.)
Land-Ocean Systems in the Siberian Arctic: Dynamics and History. Springer-Verlag. Berlin. 1999. 251-264.