RAE 35 : Some notes from the 1993-4 field season at Vostok station
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Transcript of RAE 35 : Some notes from the 1993-4 field season at Vostok station
Jean Robert Petit
Laboratoire de Glaciologie et de Géophysique de l’Environnement (LGGE)
Centre National de la Recherche Scientifique (CNRS)University J. Fourrier 38402 St Martin d’Hères cedex , France
San Petersburg 2013
RAE 35 : Some notes from the 1993-4 field season at Vostok station
19841984
1991
1992-3 field season
1991-2
1992-3
1993-4
5G bore hole
Koudriashov et al.
Chronology of events
Winter 1991 : (Kracilev A. ) - 5G drilling thermal drill.
-1991-2 : 5G got stuck at 2503 m depth
- Drilling fluid density deficit leads to probable hole closure- Project for setting a casing and for the use CFC 141b
-Winter 1992 (Moussiev B.)- Hole deviation at 2200 m depth : 5G1
-1992-3 : Setting geophysical winch and labs
-Winter 1993 (Tchistiakov V. K.)- Drilling 5G1 down to 2755 m depth
-1993-4 : Setting the casing and attempt to rise drilling fluid to the top. - Fluid penetrated into the ice and come back. - ?
2m
42 m
100 m
120m
160m
Vostok 5G hole1993-4 field season
1 2 3 4 5
230m
6
6 bars air pressure
90m
6 7 8 9
Notes from the 1993-4 field season -when filling hole, fluid level cannot be set above 42m
depth -when an air pressure is applied, fluid level went well
below casing end and close off depth of the ice (>130m) When pressure is removed, fluid come back into the
hole Conclusion :
• no leak through the casing
• fluid level cannot be risen
• fluid penetrated into the ice through the ice wall and can come back
• Possible hydro fracturing in the brittle zone
Thank you!
L. Arnaud1, G.Picard1,V. Lipenkov2, E. Lefebvre1, J.R. Petit1
1-LGGE, CNRS- University J Fourrier, St Martin d’Hères Cedex, France2- AARI, St Petersbourg, Russia
San Petersburg 2013
Snow temperature recorders (TAUTO) : preliminary data and comparison with ERA
-Improve knowledge of densification processes (one amongst ideas of J.M. Barnola)
-heat, water vapour transfers, firn ageing(diffusion properties, density, stable isotope…)
Provide « field truth » or constraints for remote sensing measurements (microwaves domain)
Compare with Réanalysis (ERA)
-Set up of temperature grapesDome C (since ~ 2008..)Vostok (since Jan. 2010): 27000 hoursS2 (since Jan. 2011)
Scientific background
Depth (cm)
0
5
10
15
20
30
40
50
60
80
100
140
200
500
1000
Data collection from flash memory to computer (RAE 56, RAE 57)
Winter game:
Remove the frost…
Daily variation
Winter warming waves
summerr
Warm events(8 day gaussian filter)
Vostok 2012
Vostok 2012
2010 2011 2012
Vostok record
Thank you!