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Norway National Report

Prepared by: Elisabeth Isaksson
email: elli (at) npolar.no

Background

The Norwegian Polar Institute conducts glaciological research in Dronning Maud Land in close collaboration with the Institute for Marine and Atmospheric Research at Utrecht University, University of Copenhagen, LGGE, British Antarctic Survey, AWI, Centre for Isotope Research in Groningen, and Stockholm University. Since 1996 the activities have been related to the EPICA programme. Norway was responsible for the Nordic EPICA pre-site survey 1996/97 and Sweden (with Norwegian participation) for a similar survey in 1997/98, as has previously been reported. Publications from these expeditions are listed below.

Recent work

Update for the 2007 - 2008 season

In 2001/02, as a part of the EPICA programme, a Nordic traverse revisited the ground traverse made by the 1996/97 Nordic EPICA pre-site survey (Fig.1). The overall aim was to both extend the shallow firn core record obtained during the last expedition as well as investigate the spatial and temporal accumulation variability at site M on the polar plateau (75°00’ S, 15°00’ E) (Table 1). This was accomplished through the retrieval of one 160 meter deep ice core at site M as well as performing an extensive radar programme around the drill site. Based on the volcanic chronology this core covers about 2500 years.

In order to investigate the spatial variability over a relatively limited area on the polar plateau six 20 meter shallow ice cores were drilled (Fig. 2) and samples from five 2 meter snow pits were collected in the vicinity of site M.

Finally, one 100 meter deep ice core was drilled at a coastal location, S100 (70°14’S, 04°48’E) and this core is estimated to cover about 300 years. For all these cores DEP, ECM and sampling for d18O were performed in an ice laboratory in the field. In addition analysis for major ions, deuterium, radionuclides are currently being completed.

Aims

Radar programme

The radar programme was conducted in order to obtain a semi-continuous spatial record of accumulation covering the same time interval as the shallow ice cores. The radar data will be used for the construction of old snow surfaces and these surfaces will be dated by the shallow ice cores. Further, the old snow surfaces will serve as boundary conditions for modelling of snow-drift and snow distribution.

The survey domain covered one 8 x 8 km square. Altogether about 400 km of radar surveys was made. The frequencies used were 900, 500, 200, and 50 MHz. The full domain was covered by a 500 m grid for the 900 and 500 MHz frequencies. In addition, two diagonals were surveyed beyond the domain. The diagonals followed the ice ridge and went perpendicular to it, respectively. The domain was oriented so the survey lines run perpendicular to the dominant wind direction. Around each drill site a finer grid (100 m) was surveyed. Further, the diagonals as well as a 1 km grid were covered with lower frequency antennas, 200 and 50 MHz, respectively. The radar systems used were GSSI SIR-2 (900 MHz and 200MHz) and RAMAC (500 MHz and 50MHz). A preliminary interpretation of the radar data suggests low variability of the recorded layers.

Future directions

  1. Compare climatic variability during the last 2000 years with both ice cores from Greenland and Svalbard and marine sediment cores from the North Atlantic.
  2. Compare Holocene climate fluctuations with Antarctic/DML marine sediment cores.
    Statistical analysis of the temporal and spatial "time" series obtained from cores and radar.
    Modelling of wind-driven snow redistribution.

ITASE related Publications from Norway

  1. Aldahan, A.A., Possnert, G., Johnsen, S.J., Clausen, H.B., Isaksson, E., Karlén, W., and Hansson, M. 1998. 60 year long 10Be records from Greenland and Antarctica. Earth and Planetary Sciences 107 (2), 139-147.
  2. Stenberg, M., Isaksson, E., Karlén, W., Hansson, M., Gundestrup, N., Mayewski, P.A.,Twickler, M., and Whitlow, S.E. 1998. Spatial and Seasonal Variability of Snow Chemistry in Western Dronning Maud Land, Antarctica. Annals of Glaciology 27, 378-384.
  3. Van den Broeke, M., Winther, J-G., Isaksson, E., Pinglot, J-F., Eiken, T., and Karlˆf, L. 1999. Climate variables along a traverse line in Dronning Maud Land, East Antarctica. Journal of Glaciology 45 (150), 295-302 .
  4. Isaksson, E., Van den Broeke, M., Winther, J-G., Karlöf, L., Pinglot, J-F., and Gundestrup, N. 1999. Accumulation and proxy-temperature variability in Dronning Maud Land, Antarctica, determined from shallow firn cores. Annals of Glaciology 29, 17-22.
  5. Stenberg, M., M. Hansson, P. Holmlund, L. Karlöf. 1999. Variability in snow layering and snow chemistry in the vicinity of two drill sites in western Dronning Maud Land, Antarctica. Annals of Glaciology, 29, 33-37.
  6. Holmlund, P., Gjerde, K., Gundestrup, N., Hansson, M., Isaksson, E., Karlöf, L., Nyman, M., Petterson, R., Pinglot, J.F., Reijmer, C., Stenberg, M., Thomassen, M.P.A., van der Veen, C., van de Wal, R.S.W., Wilhelms, F. and Winther, J-G. 2000. Spatial gradients in snow layering and ten metre temperatures at potential EPICA-DML drill sites. Annals of Glaciology 30, 13-19.
  7. Karlöf, L., Winther, J-G., Isaksson, E., Kohler, J., Stenberg, M., Thomassen, M.P.A., Wilhelms, F., Pinglot, J.F., Pettersson, R., v.d. Veen, C., Hansson, M., Holmlund, P., van de Wal, R.S.W. 2000. A 1500 years record of accumulation at Amundsenisen Western Dronning Maud Land, Antarctica, derived from electrical and radioactive measurements on an 120 m ice core. Journal of Geophysical Research 105 (D10), 12,471-12,483.
  8. Isaksson, E., Karlén, W., Mayewski, P., Twickler, M., and Whitlow, S. 2001. A high-altitude snow chemistry record from Amundsenisen, Dronning Maud Land, Antarctica. Journal of Glaciology, 47 (158), 489-496.
  9. Isaksson, E., and Melvold, K. 2002. Trends and patterns in the recent accumulation and proxy-temperature in coastal Dronnning Maud Land, Antarctica - interpretations from shallow ice cores. Annals of Glaciology 35, in press.

Reports

  1. Holmlund, P., M. Stenberg, L. Karlöf, M. Nyman, K. Gjerde, M. Thomassen..1994. Glaciological studies in East Antarctica. In Grˆnlund, E. ed. Cruise report from SWEDARP 1997798. Stockholm, Svenska Polarforskningssekretariatet, 37-45.
  2. Winther, J.-G., and 9 others. 1998. EPICA Dronning Maud land pre site survey 1996/97. In Report of the Norwegian Antarctic Research Expedition 1996/97 (Ed.: J-G. Winther), Meddelser No. 148.
  3. Winther, J.-G, and 10 others. 2002. European Project for Ice Coring in Antarctica (EPICA) –Nordic traverse in 2000/01(Ed.: J-G. Winther). Norsk Polarisntitutt Rapportserie 120.

Table 1. Location of NARE 2000/01 drill sites.

Drill site Latitude Longitude Drilled depth (m) Measurements
M20 75°0'S 15°0'E
19.2
DEP,ECM, stratigraphy, d18O
dD, major ions, radionucleids
         
MA20 74°59'S 15°6'.E 20.6 DEP,ECM, stratigraphy, d18O
dD, major ions, radionucleids
         
MB20 75°1'S 15°2'E 20.1 DEP, ECM, stratigraphy, d18O
dD, major ions, radionucleids
         
MC20 75°0'S 14°53'E 20.2 DEP, ECM, stratigraphy, d18O
dD, major ions, radionucleids
         
MD20 74°58'S 14°57'E 20.3 DEP, ECM, stratigraphy, d18O
dD, major ions, radionucleids
         
M150 75°0'S 15°0'E 160 DEP, ECM, stratigraphy, d18O
dD, major ions, radionucleids
         
M100 70°14’S 04°48’E 100 DEP, ECM, stratigraphy, d18O

drill locations map

Figure 1. Map over the study area. On the enlarged area around site M the drill locations for shallow cores as well as the corners in the radar survey domain is shown (from Winther et al., 2002). (click on figure to enlarge)

Accumulation record graph

Figure 2. Accumulation record from five firn cores, based on dating from the ECM record (from Winther et al., 2002). (click on figure to enlarge)