EGU2020-20586
https://doi.org/10.5194/egusphere-egu2020-20586
EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Continuous (CFA) CH4 record of the Elbrus ice core, Caucasus (preliminary results)

Diana Vladimirova1, Xavier Faïn2, Patrick Ginot2, Stanislav Kutuzov1, and Vladimir Mikhalenko1
Diana Vladimirova et al.
  • 1Institute of Geography, Russian Academy of Science, Department of Glaciology, Moscow, Russian Federation (dv332281@mail.ru)
  • 2Institut des Géosciences de l'Environnement, Grenoble, France

Methane (CH4) is the third most powerful greenhouse gas. However, its warming potential is two orders of magnitude higher than of carbon dioxide and its residence time in the atmosphere is only 9.1 ± 0.9 years. It makes CH4 a good indicator of rapid climate variations both under natural conditions and due to the anthropogenic influence.

The Elbrus ice core was drilled in 2009 on the Western Plato (43°20’53.9’’N, 42°25’36.0’’E) at elevation 5115 m a.s.l. It is 182 m long and is dated back to 280 ± 400 CE (Common Era). The CH4 mixing ratios were analyzed using a continuous flow analysis (CFA) system paired with optical-feedback cavity-enhanced absorption spectroscopy. The measurements campaign was organized at Institut des Géosciences de l'Environnement (IGE), Grenoble, France. This is a first high-resolution mid-latitude CH4 record. The record aims to better constrain the past evolution of mid-latitude methane sources.

Here we present preliminary results of the methane concentration measurements of the Elbrus ice core in high-resolution (CFA CH4 record). We observe in situ production (max level 2900 ppb) and a baseline. We inspect a potential origin of the multiple spikes in the high-resolution record. Supposedly, either an in-situ production in the dust-rich layers occurred or a gas dissolution in the melt layers took place. However, the possibility of in-situ production during continuous gas extraction has to be further studied. The identified melt layers can serve as an indicator of interrupted stable water isotopic signal and may be supportive in the regional temperature reconstructions based on the Elbrus ice core record. A cleaned off the spikes record is inspected for the natural variability of the CH4 baseline concentration related to the short-term climate and methane emissions variability.

How to cite: Vladimirova, D., Faïn, X., Ginot, P., Kutuzov, S., and Mikhalenko, V.: Continuous (CFA) CH4 record of the Elbrus ice core, Caucasus (preliminary results), EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-20586, https://doi.org/10.5194/egusphere-egu2020-20586, 2020

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Presentation version 4 – uploaded on 05 May 2020 , no comments
Figure 4 was added, it shows the CH4 vs rocks
Presentation version 3 – uploaded on 01 May 2020 , no comments
CFA dust credit was updated. It belongs to Patrick Ginot.
Presentation version 2 – uploaded on 01 May 2020 , no comments
Version description: Credits for the dust record are corrected. The CFA Abacus particles record is used and the credit belongs to Patrick[...]
Presentation version 1 – uploaded on 25 Apr 2020 , no comments