1 0 0 2 0 0 3 0 0 4 0 0 7 0 0
c rc r c r SS1SS2
SS3
-35 -30 -25 -20 -15 -10 -5
SS5
c r c r c r
4.5.1999
SS6 March 1999 ?
c r
SS7 DH SS8
DH c rc r SS9
DH SS10
SS11 c r
SS12
SS14SS15SS13 c rc r
SS16
SS17 m l
m l
SS18SS19 m l
Summer 1998
SS20
c r
SS21 9 ml SS22 SS23 SS24SS25 SS27 SS26
SS28
SS29
c r m l i c e c r c r c r
i c e m l SS30
SS41 SS32 SS31
SS33 m l
SS40
SS44 SS34
SS35 SS36
SS37 SS38 SS39
SS42 SS43
2 m l
m lm l
m l i c e firn raw grained
-50
-100
-150
-250
δ18O (‰) SMOW
m l m lm l
firn raw grained
firn raw grained with melting layers
firn with melting layers i c e Summer 1997
Summer 1996 0 0.2 0.4 0.6 0.81
density (g/cm3)
depth (cm)
Temperature (oC) * 0 -20 -40 0
-200
Visual stratigraphy
* according to VAIKMäE &PUNNING 1984 -0
SS4
1 2
3
The Glacier is characterized by large melting events in summer producing infiltration ice layers.
Snow of the winter 1998/99 is accumulated in the upper 60 cm (l a y e r 1 ). It has a homogeneous density. Its d18O values have a large dynamic range of nearly 15‰ probably caused by single events of precipitation. Depth hoar is well known from Central Greenland characterizing the late summer. It occurred on Academy of Sciences ice cap in 1998 (l a y e r 2 ).
In deeper horizons mixing of infil- trating summer melting water with firn is smoothing the isotope signal. Ice lenses and layers occur in an inhomogeneous pattern. Ice layers of more than 10 cm could be observed (l a y e r 3 ).
A new Holocene ice core record from Academy of Sciences ice cap, Severnaya Zemlya?
D. Fritzsche 1) , L.M. Savatyugin 2) , F. Wilhelms 1) , J.F. Pinglot 3) , H.-W. Hubberten 1) , H. Meyer 1) & H. Miller 1)
1) Alfred-Wegener-Institut für Polar und Meeresforschung, D-27568 Bremerhaven and D-14473 Potsdam, Germany
2) State Research Center - Arctic and Antarctic Research Institute, R-199226 St. Petersburg, Russia
3) Laboratoire de Glaciologie et Géophysique de l'Environnement, CNRS, F-38402 Saint Martin d'Hères Cedex, France
Severnaya Zemlya
Map:
World Atlas of snow and ice Resources, Russian Academy of Sciences, Moscow 1997, p.55
The possibility of using ice cores for past climatic recon- struction is well known from Greenland and Antarctica, but only one half of the Arctic region has ice caps.
The archipelago of Severnaya Zemlya is the most eastern Eur- asian area covered by consider- able ice caps. The Academy of Sciences ice cap (Komsomolets Island) was chosen for a new deep ice core drilling because it is the thickest and coldest one on Severnaya Zemlya. The island was continuously glaciat- ed through the whole Holocene.
Ice-core proxies from Academy of Sciencies ice cap represent the time period back to the Younger Dryas (KLEMENTEV ET.AL, 1991). The new core should be drilled to get past climate infor- mation with very high resolution.
Ice covers are shown in pink colour in the map on the left.
Academy of Sciences ice cap
First results Drilling site
0 5 1 0 1 5 2 0 2 5 3 0 3 5 4 0
0 - 5 - 1 0 - 1 5 - 2 0 - 2 5 - 3 0 - 3 5 - 4 0 - 4 5 - 5 0 - 5 5
1 5 , 6 6
2 1 , 3 6 1 6 , 8 4
2 2 , 6 8
accumulation (mWE)
depth (m) - 3 0
- 2 5 - 2 0 - 1 5 - 1 0 - 5 0
0 5 1 0 1 5 2 0 2 5 3 0 3 5 4 0 4 5 5 0
137Cs (mBq/kg)
1 9 6 2 - 6 3
depth (m)
T o p : 137Cs activity of drilling chips samples versus depth. The sample with the highest activity includes the horizon from 1962/63 with radioactive deposition from nuclear tests in 1961/62.
B e l o w : Accumulation versus depth calculated from gamma absorption density mea- surements of the ice core. The depth of the reference sample including the 1962/63 layer is corresponding with a total accumulation of 15.66 to 16.84 mWE giving a mean net mass balance of app. 4 5 c m W E / y e a r .
Mean annual net mass balance
4 5
-50 -40 -30 -20 -10
depth (m)
300 -6 200
150 100 50
Conductivity (S/m)
Bezymianny (Kamtchatka) V E I 5 , March 30,1956
250 350
*10 Pinatubo 1991 (Philippines) ?
St.Helens 1980 (USA Westcoast)?
Bezymianny 1979 (Kamtchatka) ?
1 9 6 0 1 9 9 5
1 9 6 3 1 9 8 5 1 9 9 0
1 9 8 0 1 9 7 5 1 9 7 0 1 9 6 5
1 9 5 5 1 9 5 0 1 9 4 5 1 9 4 0 1 9 3 5 1 9 3 0 1 9 2 5 1 9 2 0 1 9 1 5 1 9 1 0 1 9 0 5 Sheveluch (Kamtchatka) VEI 4, N o v . 1 2 , 1 9 6 9 ?
Sarychev (Kamtchatka), Nov.9,1946 ? Kliuchevskoi (Kamtchatka), Jan.1,1945 ?
Kliuchevskoi (Kamtchatka), March 25,1931 ?
Electrical conductivity and preliminary time scale
6 2 0 6 4 0 6 6 0 6 8 0 7 0 0 7 2 0 7 6 0
8 0 , 4 4 8 0 , 4 6 8 0 , 4 8 8 0 , 5 0 8 0 , 5 2 8 0 , 5 4
RES-Profile app. 80.515 N
6 2 0 6 4 0 6 6 0 6 8 0 7 0 0 7 2 0 7 4 0 7 6 0
9 4 , 7 9 4 , 8 9 4 , 9 9 5 9 5 , 1 9 5 , 2
RES-Profile app. 94.8 E
Ice thickness (m)Ice thickness (m)
Latitude (Deg. N)
Longitude (Deg. E) crossing profile
crossing profile 7 4 0
In 1997 J.A. DOWDESWELL carried out a programme of airborne radio-echo sounding (100 MHz) of the ice caps on Severnaya Zemlya. His database was used to find a suitable drilling site on Academy of Sciences ice cap with flat subglacial topography and low ice flow velocity.
The drilling place chosen has the coordinates 80.52N 94.81 E.
Database:
Ice thickness: DOWDESWELL, 1 9 9 9 Surface topography: map GUGK, 1991
depth (m)
summer 1984 ?
summer 1983 ?
δ 1 8O ( ‰ ) S M O W
density (g/cm3) δ D ( ‰ ) S M O W Electrical conductivity of the ice
core was determined by help of the dielectric profiling method.
The conductivity is depending on the amount of impurities in the ice, especially on acids from vulcano events. Historical vulca- no eruptions were used for dat- ing the Greenland ice cores.
The time scale given was calcu- lated assuming a mean annual net mass balance of 45 cm WE, using the 1963 reference layer.
This scale is indicating that the big event in electrical conduc- tivity data in the depth of 25.8 m is caused by the eruption of Bezymianny in 1956, the larg- est volcano event in the time covered.
References:
GUGK, 1991: Glavnoe upravlenie geo- dezii i kartografii pri Sovete Minis- t r o v S S S R , 1 : 5 0 0 0 0 0 , " o . Schmidta (Severnaya Zemlya)"
U-45-V,G, 46-V,G "m. Lokot' (Severnaya Zemlya)" U-47-V,G, 48-V,G
KLEMENTEV, O . L . , POTAPENKO, V . YU. , SAVATYUGIN, L . M . , NIKOLAEV,V . I . , 1991. Studies of the internal s t r u c t u r e a n d t h e r m a l - hydrodynamic state of the Vavi- lov Glacier, Archipelago Sever- naya Semlya. Glaciers-Ocean- Atmosphere Interactions. IAHS Publ. No. 208, p. 49-59 DOWDESWELL, J.A., 1999. Airborne
geophysical investigations of the ice caps on Severnaya Zemlya, Russian High Arctic. Final Report.
Bristol, Glaciology Centre, Report 9 9 - 0 1
Core stratigraphy and isotope data
Field activities
Tower with the KEMS-112 drill on Academy of Sciences ice cap
The drilling was started in May 1999 as a joint project of the A l f r e d W e g e n e r I n s t i t u t e (Germany), the Arctic and Ant- arctic Research Institute, and the Miining Institute (Russia, St.
Petersburg both). Camp and tower were errected and the first 54 m of core were drilled using the KEMS-112 electromecanical ice core drill, the same type used at Vostok Station, Antarctica.
In 2000 drilling will be continued in hoping to reach bedrock.
The example core sequence clearly shows layers of infiltration ice produced by refreezing melting water. These irregularities are apparent in the density and isotope profiles.
5 0 0 6 0 0
