Glacier changes in the Pascua-Lama region, Chilean Andes (29° S): recent mass balance and 50 yr surface area variations

Abstract

Abstract. Since 2003, a monitoring program has been conducted on several glaciers and glacierets in the Pascua-Lama region of the Chilean Andes (29 • S/70 • W; 5000 m a.s.l.), permitting the study of glaciological processes on ice bodies in a subtropical, arid, high-elevation area where no measurements were previously available. In this paper we present: (1) six years of glaciological surface mass balance measurements from four ice bodies in the area, including a discussion of the nature of the studied glaciers and glacierets and characterization of the importance of winter mass balance to annual mass balance variability; and (2) changes in surface area of twenty ice bodies in the region since 1955, reconstructed from aerial photographs and satellite images, which shows that the total glaciated surface area reduced by ∼29 % between 1955 and 2007, and that the rate of surface area shrinkage increased in the late 20th century. Based on these datasets we present a first interpretation of glacier changes in relation with climatic parameters at both local and regional scales.

Glacier contribution to streamflow in two headwaters of the Huasco River, Dry Andes of Chile

“…For the sake of simplicity we use the word glacier to designate both landforms in the following sections. All studied glaciers can be classified as cold glaciers (Rabatel et al, 2011).…”

“…For example, glacier shrinkage in the Dry Andes region (sensu Lliboutry, 1998, i.e. between 20 • S-35 • S), has been well described (Leiva, 1999;Rivera et al, 2002;Le Quesne et al, 2009;Rabatel et al, 2011), yet the role of these glaciers in the hydrological cycle is much less documented. This discrepancy might be due to fact that glacial retreat is observable by remote sensing techniques, whereas hydrological balance studies require collecting field data in an environment difficult to access, especially in the Dry Andes, where glaciers occur at altitudes of 3000 m to nearly 7000 m a.s.l.…”

Mass loss and imbalance of glaciers along the Andes Cordillera to the sub-Antarctic islands

“…For the last decades most of Earth's glaciers, including South American glaciers (e.g., Georges 2004;Casassa et al 2007;Masiokas et al 2008;Rabatel et al 2011Rabatel et al , 2013, have undergone general thinning and recession (e.g., WGMS 2012; IPCC 2013, Chapter 4; Leclercq et al 2014). Glacier annual mass-balance (Ba) observations from the last decades have shown an overall increase in mass loss (Cogley 2009(Cogley , 2012Dyurgerov 2010), resulting in more negative annual Ba during the first pentad (five years) of the first decade of the new millennium (WGMS 2013).…”

“…On an individual glacier scale, Rignot et al (2003), Davies and Glasser (2012), Willis et al (2012aWillis et al ( , 2012b, and Schaefer et al (2013, for example, performed area and mass-balance analysis studies specifically for the Patagonia ice fields using radar observations, satellite-based observations, and simulations, respectively, whilst Kaser et al (2003), Francou et al (2004), Casassa et al (2006), Pellicciotti et al (2008), Vuille et al (2008), Buttstadt et al (2008), Rabatel et al (2011, 2013), and MacDonell et al (2013 performed mass-balance analysis for glaciers in Tierra del Fuego and the Andes Cordillera using the glaciological method, firn cores, and simulations. In several of these examples, Ba time series were compared with different large-scale atmospheric and oceanic indices.…”

Weak properties and robustness of t-Hill estimators

“…Such gain and loss of mass can be analyzed as a balance (or budget). Guanaco glacier is located in the III region of Chile (latitude 29 • S) in the semi-arid Andes, it has a surface area of 1.86[km 2 ] and a maximum thickness of 120[m], see Rabatel et al (2011), the area contributing water to the Pacific Ocean (included in the above calculation of 23 %), is only 1.26[km 2 ], in other words, less than 35 % of the total ice area in this zone. The rest of the Guanaco glacier contributes water to the Atlantic ocean.…”