Post-Little Ice Age Equilibrium-Line Altitude and Temperature Changes in the Greater Caucasus Based on Small Glaciers

Levan G. Tielidze; Andrew N. Mackintosh; Alexander Gavashelishvili; Lela Gadrani; Akaki Nadaraia; Mikheil Elashvili

doi:10.3390/rs17091486

Post-Little Ice Age Equilibrium-Line Altitude and Temperature Changes in the Greater Caucasus Based on Small Glaciers

Levan G. Tielidze
, Andrew N. Mackintosh
, Alexander Gavashelishvili
, Lela Gadrani
, Akaki Nadaraia
, Mikheil Elashvili

School of Earth Atmosphere and Environment

Research output: Contribution to journal › Article › Research › peer-review

17 Citations (Scopus)

Abstract

Understanding glacier and climate variations since pre-Industrial times is crucial for evaluating the present-day glacier response to climate change. Here, we focus on twelve small glaciers (≤2.0 km²) on both the northern and southern slopes of the Greater Caucasus to assess post-Little Ice Age glacier–climate fluctuations in this region. We reconstructed the Little Ice Age glacier extent using a manual detection method based on moraines. More recent glacier fluctuations were reconstructed using historical topographical maps and satellite imagery. Digital elevation models were used to estimate the topographic characteristics of glaciers. We also used the accumulation area ratio (AAR) method and a regional temperature lapse rate to reconstruct glacier snowlines and corresponding temperatures since the 1820s. The results show that all selected glaciers have experienced area loss, terminus retreat, and equilibrium line altitude (ELA) uplift over the last 200 years. The total area of the glaciers has decreased from 19.1 ± 0.9 km² in the 1820s to 9.7 ± 0.2 km² in 2020, representing a −49.2% loss, with an average annual reduction of −0.25%. The most dramatic reduction occurred between the 1960s and 2020, when the glacier area shrank by −35.5% or −0.59% yr⁻¹. The average terminus retreat for all selected glaciers was −1278 m (−6.4 m/yr⁻¹) during the last 200 years, while the average retreat over the past 60 years was −576 m (−9.6 m/yr⁻¹). AAR-based (0.6 ± 0.05) ELA reconstructions from all twelve glaciers suggest that the average ELA in the 1820s was about 180 m lower (3245 ± 50 m a.s.l.) than today (3425 ± 50 m a.s.l.), corresponding to surface air temperatures <1.1 ± 0.3 °C than today (2001–2020). The largest warming occurred between the 1960s and today, when snowlines rose by 105 m and air temperatures increased by <0.6 ± 0.3 °C. This study represents a first attempt at using glacier evidence to estimate climate changes in the Caucasus region since the Little Ice Age, and it can be used as a baseline for future studies.

Original language	English
Article number	1486
Number of pages	26
Journal	Remote Sensing
Volume	17
Issue number	9
DOIs	https://doi.org/10.3390/rs17091486
Publication status	Published - May 2025

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

SDG 13 Climate Action

Keywords

equilibrium-line altitude (ELA)
Greater Caucasus
Little Ice Age (LIA)
post-industrial temperature change
snowline

Access to Document

10.3390/rs17091486Licence: CC BY

Cite this

@article{61ab5abd7b2c4fe28fcbfe9ca321a1ec,

title = "Post-Little Ice Age Equilibrium-Line Altitude and Temperature Changes in the Greater Caucasus Based on Small Glaciers",

abstract = "Understanding glacier and climate variations since pre-Industrial times is crucial for evaluating the present-day glacier response to climate change. Here, we focus on twelve small glaciers (≤2.0 km2) on both the northern and southern slopes of the Greater Caucasus to assess post-Little Ice Age glacier–climate fluctuations in this region. We reconstructed the Little Ice Age glacier extent using a manual detection method based on moraines. More recent glacier fluctuations were reconstructed using historical topographical maps and satellite imagery. Digital elevation models were used to estimate the topographic characteristics of glaciers. We also used the accumulation area ratio (AAR) method and a regional temperature lapse rate to reconstruct glacier snowlines and corresponding temperatures since the 1820s. The results show that all selected glaciers have experienced area loss, terminus retreat, and equilibrium line altitude (ELA) uplift over the last 200 years. The total area of the glaciers has decreased from 19.1 ± 0.9 km2 in the 1820s to 9.7 ± 0.2 km2 in 2020, representing a −49.2\% loss, with an average annual reduction of −0.25\%. The most dramatic reduction occurred between the 1960s and 2020, when the glacier area shrank by −35.5\% or −0.59\% yr−1. The average terminus retreat for all selected glaciers was −1278 m (−6.4 m/yr−1) during the last 200 years, while the average retreat over the past 60 years was −576 m (−9.6 m/yr−1). AAR-based (0.6 ± 0.05) ELA reconstructions from all twelve glaciers suggest that the average ELA in the 1820s was about 180 m lower (3245 ± 50 m a.s.l.) than today (3425 ± 50 m a.s.l.), corresponding to surface air temperatures <1.1 ± 0.3 °C than today (2001–2020). The largest warming occurred between the 1960s and today, when snowlines rose by 105 m and air temperatures increased by <0.6 ± 0.3 °C. This study represents a first attempt at using glacier evidence to estimate climate changes in the Caucasus region since the Little Ice Age, and it can be used as a baseline for future studies.",

keywords = "equilibrium-line altitude (ELA), Greater Caucasus, Little Ice Age (LIA), post-industrial temperature change, snowline",

author = "Tielidze, \{Levan G.\} and Mackintosh, \{Andrew N.\} and Alexander Gavashelishvili and Lela Gadrani and Akaki Nadaraia and Mikheil Elashvili",

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month = may,

doi = "10.3390/rs17091486",

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AU - Tielidze, Levan G.

AU - Mackintosh, Andrew N.

AU - Gavashelishvili, Alexander

AU - Gadrani, Lela

AU - Nadaraia, Akaki

AU - Elashvili, Mikheil

PY - 2025/5

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N2 - Understanding glacier and climate variations since pre-Industrial times is crucial for evaluating the present-day glacier response to climate change. Here, we focus on twelve small glaciers (≤2.0 km2) on both the northern and southern slopes of the Greater Caucasus to assess post-Little Ice Age glacier–climate fluctuations in this region. We reconstructed the Little Ice Age glacier extent using a manual detection method based on moraines. More recent glacier fluctuations were reconstructed using historical topographical maps and satellite imagery. Digital elevation models were used to estimate the topographic characteristics of glaciers. We also used the accumulation area ratio (AAR) method and a regional temperature lapse rate to reconstruct glacier snowlines and corresponding temperatures since the 1820s. The results show that all selected glaciers have experienced area loss, terminus retreat, and equilibrium line altitude (ELA) uplift over the last 200 years. The total area of the glaciers has decreased from 19.1 ± 0.9 km2 in the 1820s to 9.7 ± 0.2 km2 in 2020, representing a −49.2% loss, with an average annual reduction of −0.25%. The most dramatic reduction occurred between the 1960s and 2020, when the glacier area shrank by −35.5% or −0.59% yr−1. The average terminus retreat for all selected glaciers was −1278 m (−6.4 m/yr−1) during the last 200 years, while the average retreat over the past 60 years was −576 m (−9.6 m/yr−1). AAR-based (0.6 ± 0.05) ELA reconstructions from all twelve glaciers suggest that the average ELA in the 1820s was about 180 m lower (3245 ± 50 m a.s.l.) than today (3425 ± 50 m a.s.l.), corresponding to surface air temperatures <1.1 ± 0.3 °C than today (2001–2020). The largest warming occurred between the 1960s and today, when snowlines rose by 105 m and air temperatures increased by <0.6 ± 0.3 °C. This study represents a first attempt at using glacier evidence to estimate climate changes in the Caucasus region since the Little Ice Age, and it can be used as a baseline for future studies.

AB - Understanding glacier and climate variations since pre-Industrial times is crucial for evaluating the present-day glacier response to climate change. Here, we focus on twelve small glaciers (≤2.0 km2) on both the northern and southern slopes of the Greater Caucasus to assess post-Little Ice Age glacier–climate fluctuations in this region. We reconstructed the Little Ice Age glacier extent using a manual detection method based on moraines. More recent glacier fluctuations were reconstructed using historical topographical maps and satellite imagery. Digital elevation models were used to estimate the topographic characteristics of glaciers. We also used the accumulation area ratio (AAR) method and a regional temperature lapse rate to reconstruct glacier snowlines and corresponding temperatures since the 1820s. The results show that all selected glaciers have experienced area loss, terminus retreat, and equilibrium line altitude (ELA) uplift over the last 200 years. The total area of the glaciers has decreased from 19.1 ± 0.9 km2 in the 1820s to 9.7 ± 0.2 km2 in 2020, representing a −49.2% loss, with an average annual reduction of −0.25%. The most dramatic reduction occurred between the 1960s and 2020, when the glacier area shrank by −35.5% or −0.59% yr−1. The average terminus retreat for all selected glaciers was −1278 m (−6.4 m/yr−1) during the last 200 years, while the average retreat over the past 60 years was −576 m (−9.6 m/yr−1). AAR-based (0.6 ± 0.05) ELA reconstructions from all twelve glaciers suggest that the average ELA in the 1820s was about 180 m lower (3245 ± 50 m a.s.l.) than today (3425 ± 50 m a.s.l.), corresponding to surface air temperatures <1.1 ± 0.3 °C than today (2001–2020). The largest warming occurred between the 1960s and today, when snowlines rose by 105 m and air temperatures increased by <0.6 ± 0.3 °C. This study represents a first attempt at using glacier evidence to estimate climate changes in the Caucasus region since the Little Ice Age, and it can be used as a baseline for future studies.

KW - equilibrium-line altitude (ELA)

KW - Greater Caucasus

KW - Little Ice Age (LIA)

KW - post-industrial temperature change

KW - snowline

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DO - 10.3390/rs17091486

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AN - SCOPUS:105004882147

SN - 2072-4292

VL - 17

JO - Remote Sensing

JF - Remote Sensing

IS - 9

M1 - 1486

ER -

Post-Little Ice Age Equilibrium-Line Altitude and Temperature Changes in the Greater Caucasus Based on Small Glaciers

Abstract

UN SDGs

Keywords

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SAEF: Securing Antarctica’s Environmental Future – An Evidence-Based, Informatics Approach

Cite this

Post-Little Ice Age Equilibrium-Line Altitude and Temperature Changes in the Greater Caucasus Based on Small Glaciers

Abstract

UN SDGs

Keywords

Access to Document

Other files and links

Projects

SAEF: Securing Antarctica’s Environmental Future – An Evidence-Based, Informatics Approach

Cite this