Stagnant ice and age modelling in the Dome C region, Antarctica
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Published:2023-08-24
Issue:8
Volume:17
Page:3461-3483
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ISSN:1994-0424
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Container-title:The Cryosphere
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language:en
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Short-container-title:The Cryosphere
Author:
Chung AilsaORCID, Parrenin FrédéricORCID, Steinhage DanielORCID, Mulvaney RobertORCID, Martín CarlosORCID, Cavitte Marie G. P.ORCID, Lilien David A.ORCID, Helm VeitORCID, Taylor Drew, Gogineni Prasad, Ritz CatherineORCID, Frezzotti MassimoORCID, O'Neill Charles, Miller Heinrich, Dahl-Jensen Dorthe, Eisen OlafORCID
Abstract
Abstract. The European Beyond EPICA project aims to extract a continuous ice core of up to 1.5 Ma, with a maximum age density of 20 kyr m−1 at Little Dome C (LDC).
We present a 1D numerical model which calculates the age of the ice around Dome C. The model inverts for basal conditions and accounts either for melting or for a layer of stagnant ice above the bedrock. It is constrained by internal reflecting horizons traced in radargrams and dated using the EPICA Dome C (EDC) ice core age profile. We used three different radar datasets ranging from a 10 000 km2 airborne survey down to 5 km long ground-based radar transects over LDC. We find that stagnant ice exists in many places, including above the LDC relief where the new Beyond EPICA drill site (BELDC) is located. The modelled thickness of this layer of stagnant ice roughly corresponds to the thickness of the basal unit observed in one of the radar surveys and in the autonomous phase-sensitive radio-echo sounder (ApRES) dataset. At BELDC, the modelled stagnant ice thickness is 198±44 m and the modelled oldest age of ice is 1.45±0.16 Ma at a depth of 2494±30 m. This is very similar to all sites situated on the LDC relief, including that of the Million Year Ice Core project being conducted by the Australian Antarctic Division.
The model was also applied to radar data in the area 10–15 km north of EDC (North Patch), where we find either a thin layer of stagnant ice (generally <60 m) or a negligible melt rate (<0.1 mm yr−1). The modelled maximum age at North Patch is over 2 Ma in most places, with ice at 1.5 Ma having a resolution of 9–12 kyr m−1, making it an exciting prospect for a future Oldest Ice drill site.
Publisher
Copernicus GmbH
Subject
Earth-Surface Processes,Water Science and Technology
Reference45 articles.
1. AntArchitecture Steering Committee: AntArchitecture,
https://www.scar.org/science/antarchitecture/, last access: 22 July 2023. a 2. Bazin, L., Landais, A., Lemieux-Dudon, B., Toyé Mahamadou Kele, H., Veres, D., Parrenin, F., Martinerie, P., Ritz, C., Capron, E., Lipenkov, V., Loutre, M.-F., Raynaud, D., Vinther, B., Svensson, A., Rasmussen, S. O., Severi, M., Blunier, T., Leuenberger, M., Fischer, H., Masson-Delmotte, V., Chappellaz, J., and Wolff, E.: An optimized multi-proxy, multi-site Antarctic ice and gas orbital chronology (AICC2012): 120–800 ka, Clim. Past, 9, 1715–1731, https://doi.org/10.5194/cp-9-1715-2013, 2013. a, b, c, d, e, f, g, h, i 3. Bell, R. E., Ferraccioli, F., Creyts, T. T., Braaten, D., Corr, H., Das, I.,
Damaske, D., Frearson, N., Jordan, T., Rose, K., Studinger, M., and Wolovick,
M.: Widespread persistent thickening of the east antarctic ice sheet by
freezing from the base, Science, 331, 1592–1595,
https://doi.org/10.1126/science.1200109, 2011. a 4. Brennan, P. V., Lok, L. B., Nicholls, K., and Corr, H.: Phase-sensitive FMCW
radar system for high-precision antarctic ice shelf profile monitoring, IET Radar Sonar Nav., 8, 776–786, https://doi.org/10.1049/iet-rsn.2013.0053,
2014. a 5. Buizert, C., Fudge, T. J., Roberts, W. H. G., Steig, E. J., Sherriff-Tadano,
S., Ritz, C., Lefebvre, E., Edwards, J., Kawamura, K., Oyabu, I., Motoyama,
H., Kahle, E. C., Jones, T. R., Abe-Ouchi, A., Obase, T., Martin, C., Corr,
H., Severinghaus, J. P., Beaudette, R., Epifanio, J. A., Brook, E. J.,
Martin, K., Chappellaz, J., Aoki, S., Nakazawa, T., Sowers, T. A., Alley,
R. B., Ahn, J., Sigl, M., Severi, M., Dunbar, N. W., Svensson, A.,
Fegyveresi, J. M., He, C., Liu, Z., Zhu, J., Otto-Bliesner, B. L., Lipenkov,
V. Y., Kageyama, M., and Schwander, J.: Antarctic surface temperature and
elevation during the Last Glacial Maximum, Science, 372, 1097–1101,
https://doi.org/10.1126/science.abd2897, 2021. a
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