An Updated Multi-Temporal Glacier Inventory for the Patagonian Andes With Changes Between the Little Ice Age and 2016

Abstract

We present a satellite-derived glacier inventory for the whole Patagonian Andes south of 45. 5 • S and Tierra del Fuego including recent changes. Landsat TM/ETM+ and OLI satellite scenes were used to detect changes in the glacierized area between 1986, 2005 and 2016 for all of the 11,209 inventoried glaciers using a semi-automated procedure. Additionally we used geomorphological evidence, such as moraines and trimlines to determine the glacierized area during the Little Ice Age for almost 90% of the total glacierized area. Within the last ∼150 years the glacierized area was reduced from 28,091 ± 890 km 2 to 22,636 ± 905 km 2 , marking an absolute area loss of 5,455 ± 1,269 km 2 (19.4 ± 4.5%). For the whole study region, the annual area decrease was moderate until 1986 with 0.10 ± 0.04% a −1. Afterwards the area reduction increased, reaching annual values of 0.33 ± 0.28% a −1 and 0.25 ± 0.50% a −1 for the periods of 1986-2005 and 2005-2016, respectively. There is a high variability of change rates throughout the Patagonian Andes. Small glaciers, especially in the north of the Northern Patagonian Icefield (NPI) and between the latter and the Southern Patagonian Icefield (SPI) had over all periods the highest rates of shrinkage, exceeding 0.92 ± 1.22% a −1 during 2005-2016. In the mountain range of the Cordillera Darwin (CD), and also accounting for small ice fields south of 52 • S, highest rates of shrinkage occurred during 1986-2005, reaching values up to 0.45 ± 0.23% a −1 , but decreased during the 2005-2016 period. Across the Andean main crest, the eastern parts of the NPI, SPI and adjoined glaciers had in absolute values the highest area reduction exceeding 2,145 ± 486 km 2 since the LIA. Large calving glaciers show a smaller relative decrease rate compared to land-terminating glaciers but account for the most absolute area loss. In general, glacier shrinkage is dependent on latitude, the initial glacier area, the environment of the glacial tongue (calving or non-calving glaciers) and in parts by glacial aspect.

Glacier Mass Changes of Lake-Terminating Grey and Tyndall Glaciers at the Southern Patagonia Icefield Derived From Geodetic Observations and Energy and Mass Balance Modeling

“…The study sites Grey and Tyndall glaciers are located at the southeastern part of the SPI (50.7 (Figure 1). In 2016, glacier areas were 239.0 and 301.4 km 2 , respectively (Meier et al, 2018). The Equilibrium Line Altitude (ELA) is estimated to be 970 ± 50 m above sea level (a.s.l.)…”

“…The location of Grey and Tyndall glaciers at the SPI and the location of the weather stations Puerto Eden, O'Higgins, Amalia, Tyndall and Grey, (B) Grey Glacier including the location of AWS Grey, (C) Tyndall Glacier including the location of AWS Tyndall. Glacier outlines are visualized for 2000 based on the RGI 5.0 and for 2016 based on a new glacier inventory by Meier et al (2018). The coordinates are in UTM zone 18S in meters.…”

Air Temperature Characteristics, Distribution, and Impact on Modeled Ablation for the South Patagonia Icefield

“…Patagonia (40-55°S) contains the largest glacierized area in South America, but recent evidence shows that most of these glaciers are shrinking rapidly (Davies & Glasser, 2012;Foresta et al, 2018;Malz et al, 2018;Meier et al, 2018;White & Copland, 2015). This deglaciation is primarily a matter of concern for sea level rise (Foresta et al, 2018;Gardner et al, 2013;Rignot et al, 2003;Willis et al, 2012).…”

Late Holocene Glacial Fluctuations of Schiaparelli Glacier at Monte Sarmiento Massif, Tierra del Fuego (54°24′ S)

“…The amount of precipitation exceeds several thousand millimeter per year [mma −1 ] on the western side, but decreases rapidly towards the east due to the foehn effect, forming one of the world´s sharpest moisture gradients [6,7]. Though the Pacific Ocean causes moderate temperatures, the vast sum of precipitation nourishes more than 11,000 glaciers south of 45.5 • S, covering an area of 22,636 ± 905 km 2 in 2016/17 [8] ( Figure 1A). mountain range of the Cordillera Darwin (CD) on Tierra del Fuego is predominantly west-east orientated.…”

“…In addition to the otherwise dominant westerly winds, the CD lies within the sphere of influence of sub-Antarctic air masses, and glaciers may respond differently to climatic changes [9,10]. Although the ~250 km wide CD and the nearby islands comprise over 2100 individual glaciers (2931 ± 155 km 2 [8]), most studies dealing with Holocene glacial variability have focused on the Northern Patagonian Icefield (NPI) and Southern Patagonian Icefield (SPI), while only a few have related to the Magallanes-Tierra del Fuego region [11,12]. Besides the limited accessibility of the fjord-seamed mountain range ( Figure 1B), around 60% of the total glacierized area is either fjord-or laketerminating, resulting in a limited terrestrial evidence of glacial variability [8,10].…”