| Summary: | The reconstruction of past climate variability offers important information about our climate system. Ice cores extracted from polar ice sheets or from mountainous glaciers are among the most popular climate archives. Ice cores from Andean glaciers in South America have been studied since the 1980’s. Almost ten ice cores have been extracted from the equator to Patagonia. They cover different time periods from the last century to the last glacial-interglacial termination that started 21,000 years ago. Those ice cores are usually dated by using a combination of methods: annual layers counting in both isotopic and chemical ice composition, radionuclides concentration analysis to detect atmospheric nuclear tests during the 20th century and ice flow modeling for the deepest part of those cores. This paper presents two interesting results arising from the isotopic composition of the ice. The first one deals with the isotopic records of Bolivian (Illimani) and Peruvian (Quelccaya) ice cores in regards to the reconstruction of glacier extent during the little ice age in the 17th-18th century. Both approaches suggest a slightly moister and cooler period from 1650 to 1780. The second result arises from the 120-year long isotopic record of an ice core drilled in Patagonia (San Valentin). It suggests that at the regional scale, temperature has regularly decreased of about 0.2 °C per decade, extending the temperature decrease shown by Chilean meteorological data since the 1970’s despite a global warming. Reconstruire les variations passées de notre climat permet de mieux appréhender le fonctionnement de notre système climatique. Les carottes de glace issues des calottes polaires et des glaciers montagneux de haute altitude sont de très bonnes archives climatiques. Les glaciers présents sur les sommets des Andes sud-américaines sont ainsi exploités depuis les années 80. Une dizaine de carottages ont été réalisés depuis l’équateur jusqu’en Patagonie. Ils recouvrent des périodes très différentes allant du dernier siècle, ...
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