New insights into the decadal variability in glacier volume of a tropical ice cap, Antisana (0°29′ S, 78°09′ W), explained by the morpho-topographic and climatic context
<p>We present a comprehensive study of the evolution of the glaciers on the Antisana ice cap (tropical Andes) over the period 1956–2016. Based on geodetic observations of aerial photographs and high-resolution satellite images, we explore the effects of morpho-topographic and climate variables...
Main Authors: | , , , , , , |
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Format: | Article |
Language: | English |
Published: |
Copernicus Publications
2022-11-01
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Series: | The Cryosphere |
Online Access: | https://tc.copernicus.org/articles/16/4659/2022/tc-16-4659-2022.pdf |
Summary: | <p>We present a comprehensive study of the evolution of the glaciers
on the Antisana ice cap (tropical Andes) over the period 1956–2016. Based on
geodetic observations of aerial photographs and high-resolution satellite
images, we explore the effects of morpho-topographic and climate variables
on glacier volumes. Contrasting behaviour was observed over the whole
period, with two periods of strong mass loss, 1956–1964 (<span class="inline-formula">−0.72</span> m w.e. yr<span class="inline-formula"><sup>−1</sup></span>) and 1979–1997 (<span class="inline-formula">−0.82</span> m w.e. yr<span class="inline-formula"><sup>−1</sup></span>), and two periods with
slight mass loss, 1965–1978 (0.10 m w.e. yr<span class="inline-formula"><sup>−1</sup></span>) and 1998–2016 (<span class="inline-formula">−0.26</span> m w.e. yr<span class="inline-formula"><sup>−1</sup></span>). There was a 42 % reduction in the total surface area of
the ice cap. Individually, glacier responses were modulated by
morpho-topographic variables (e.g. maximum and median altitude and surface
area), particularly in the case of the small tongues located at low
elevations (Glacier 1, 5 and 16) which have been undergoing accelerated
disintegration since the 1990s and will likely disappear in the coming
years. Moreover, thanks to the availability of aerial data, a surging event
was detected on the Antisana Glacier 8 (G8) in the 2009–2011 period; such an event is
extremely rare in this region and deserves a dedicated study. Despite the
effect of the complex topography, glaciers have reacted in agreement with changes
in climate forcing, with a stepwise transition towards warmer and
alternating wet–dry conditions since the mid-1970s. Long-term decadal
variability is consistent with the warm–cold conditions observed in the
Pacific Ocean represented by the Southern Oscillation index.</p> |
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ISSN: | 1994-0416 1994-0424 |