# New Late Glacial and Holocene 36Cl and 10Be moraine chronologies from sub-Antarctic Kerguelen Archipelago

Joanna Charton, Vincent Jomelli, Irene Schimmelpfennig, Deborah Verfaillie, Vincent Favier, Guillaume Delpech, Regis Braucher, Pierre-Henri Blard, V.R. Rinterknecht, Léo Chassiot, et al.

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## To cite this version:

Joanna Charton, Vincent Jomelli, Irene Schimmelpfennig, Deborah Verfaillie, Vincent Favier, et al. New Late Glacial and Holocene 36Cl and 10Be moraine chronologies from sub-Antarctic Kerguelen Archipelago. EGU General Assembly 2021, Apr 2021, Vienna (online), France. 10.5194/egusphere-egu21-9883. hal-03419239

HAL Id: hal-03419239

https://hal.science/hal-03419239

Submitted on 8 Nov 2021

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# New Late Glacial and Holocene $^{36}$Cl and $^{10}$Be moraine chronologies from sub-Antarctic Kerguelen Archipelago

Joanna Charton<fnref n="1" />, Vincent Jomelli<fnref n="1" />, Irene Schimmelpfennig<fnref n="1" />, Deborah Verfaillie<fnref n="2" />, Vincent Favier<fnref n="3" />, Guillaume Delpech<fnref n="4" />, Régis Braucher<fnref n="1" />, Pierre-Henri Blard<fnref n="5" />, Vincent Rinterknecht<fnref n="1" />, Léo Chassiot<fnref n="6" />, Georges Aumaître<fnref n="1" />,<fnref n="7" />, Didier L. Bourlès<fnref n="1" />,<fnref n="7" />, and Karim Keddadouche<fnref n="1" />,<fnref n="7" />

The Kerguelen Archipelago (49°S, 69°E) is an excellent location for the study of multi-millennial
glacier fluctuations, since it is the largest still glaciated emerged area (552 km<fnref n="2" /> in 2001) in the sub-
Antarctic sector of the Indian Ocean, where many glacio-geomorphological formations such as
moraines may be dated. To investigate the so-far little-known Late Glacial and the Holocene glacier
fluctuations in Kerguelen, we apply cosmogenic nuclide dating of moraines in 3 glacial valleys: Val
Travers valley, Ampere glacier valley and Arago glacier valley. We use in situ $^{36}$Cl dating of the
basaltic moraine boulders at the first two sites, and $^{10}$Be dating of the quartz-bearing syenite
boulders at the third site. The new $^{36}$Cl and $^{10}$Be exposure ages provide time constraints over the
last 17,000 years. A glacial advance was highlighted during the Late Glacial at 14.4 ± 1.4 ka ago,
probably linked to the Antarctic Cold Reversal event. These results are consistent with those
previously obtained on the archipelago (Jomelli et al., 2017, 2018; Charton et al., 2020) and more
generally those from other the sub-Antarctic regions (e.g. Sagredo et al., 2018). This suggests that
all glaciers at this latitude were broadly sensitive to this specific climatic signal. No Early nor Mid
Holocene advances were evidenced in Kerguelen glacier evolution during the Holocene due to
missing moraines that may have formed in these specific periods. Radiocarbon-dated peat,
published in the 1990s, provides evidence of less extensive glacier extents during the Early
Holocene than during the Late Holocene (Frenot et al., 1997). Finally, glaciers seem to have re-
advanced only during the Late Holocene, especially within the last millennium, at ≈1 ka, ≈620 years
and ≈390 years (Verfaillie et al., submitted). A comparison of this new dataset with the available
$^{10}$Be ages from other sub-Antarctic regions allows for the identification of 3 different glacier
evolution patterns during the Holocene. The glacial fluctuations experienced by Kerguelen glaciers
seems particularly uncommon, and are likely due to its singular location in the Southern Indian
Ocean. Finally, climatic factors that may explain the Kerguelen glacier evolution (temperature,
precipitation) are discussed. To this end, we investigate the chronology of glacier advance/retreat

<footnote n="1">¹Aix Marseille Univ., CNRS, IRD, INRAE, Coll France, UM 34 CEREGE, Aix-en-Provence, France</footnote>

<footnote n="2">²Earth and Life Institute, Université catholique de Louvain, Louvain-la-Neuve, Belgique</footnote>

<footnote n="3">³Université Grenoble Alpes, IGE, CNRS, Grenoble, France</footnote>

<footnote n="4">⁴Université Paris-Saclay, CNRS, GEOPS, 91405 Orsay, France</footnote>

<footnote n="5">⁵Université de Lorraine, CNRS, CRPG, Vandœuvre-lès-Nancy, France</footnote>

<footnote n="6">⁶Université Laval, Département de Géographie, CEN, Québec, QC, Canada</footnote>

<footnote n="7">⁷ASTER Team</footnote>
periods with (i) the variation in atmospheric temperatures recorded in ice cores in Antarctica and
(ii) the variation in precipitation (Southern Westerly Winds, Southern Annular Mode).

Charton et al., 2020 : Ant. Sci. 1-13

Frenot et al., 1997 : C.R. Acad. Sci. Paris Life Sciences 320, 567-573

Jomelli et al., 2017 : Quat. Sci. Rev. 162, 128-144

Jomelli et al., 2018 : Quat. Sci. Rev. 183, 110-123

Sagredo et al., 2018 : Quat Sci. Rev. 188, 160-166

Verfaillie et al., submitted