Quantifying mass balance processes on the Southern Patagonia Icefield

Schaefer, Marius; Machguth, Horst; Falvey, Mark; Casassa, Gino; Rignot, Eric

doi:10.5194/tc-9-25-2015

Cited by 80 publications

(121 citation statements)

References 40 publications

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“…These values are 1 order of magnitude larger (more negative) than the values reported for the rest of the glaciers in the Southern Andes and do not follow the decreasing north-south trend found for smaller glaciers by Mernild et al (2015). Schaefer et al (2015) suggested that calving fluxes, which apparently increased in the last decade, are probably the cause of the high mass loss of the southern Patagonian ice field, which according to their mass balance model showed an overall positive surface mass balance between 1975 and 2011.…”

Section: Mass Balance Of Monte Tronador Glaciers In a Regional Perspecontrasting

confidence: 38%

Recent geodetic mass balance of Monte Tronador glaciers, northern Patagonian Andes

et al. 2017

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Abstract. Glaciers in the northern Patagonian Andes (35-46 • S) have shown a dramatic decline in area in the last decades. However, little is known about glacier mass balance changes in this region. This study presents a geodetic mass balance estimate of Monte Tronador (41.15 • S; 71.88 • W) glaciers by comparing a Pléiades digital elevation model (DEM) acquired in 2012 with the Shuttle Radar Topography Mission (SRTM) X-band DEM acquired in 2000. We find a slightly negative Monte-Tronador-wide mass budget of −0.17 m w.e. a −1 (ranging from −0.54 to 0.14 m w.e. a −1 for individual glaciers) and a slightly negative trend in glacier extent (−0.16 % a −1 ) over the 2000-2012 period. With a few exceptions, debris-covered valley glaciers that descend below a bedrock cliff are losing mass at higher rates, while mountain glaciers with termini located above this cliff are closer to mass equilibrium. Climate variations over the last decades show a notable increase in warm season temperatures in the late 1970s but limited warming afterwards. These warmer conditions combined with an overall drying trend may explain the moderate ice mass loss observed at Monte Tronador. The almost balanced mass budget of mountain glaciers suggests that they are probably approaching a dynamic equilibrium with current (post-1977) climate, whereas the valley glaciers tongues will continue to retreat. The slightly negative overall mass budget of Monte Tronador glaciers contrasts with the highly negative mass balance estimates observed in the Patagonian ice fields further south.

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Section: Mass Balance Of Monte Tronador Glaciers In a Regional Perspecontrasting

confidence: 38%

Recent geodetic mass balance of Monte Tronador glaciers, northern Patagonian Andes

et al. 2017

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“…Direct glaciological observations in this remote region are still scarce, mainly due to the region's inaccessibility and its harsh climate (Buttstädt et al, 2009;Mernild et al, 2015;Schaefer et al, 2015). In recent decades, remote sensing techniques have enabled the spatial coverage of glaciological observations to be extended.…”

Section: Introductionmentioning

confidence: 99%

Geodetic Mass Balance of the Northern Patagonian Icefield from 2000 to 2012 Using Two Independent Methods

2018

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We compare two independent estimates of the rate of elevation change and geodetic mass balance of the Northern Patagonian Icefield (NPI) between 2000 (3,856 km 2 ) and 2012 (3,740 km 2 ) from space-borne data. Both methods lead to similar and strongly negative icefield-wide mass balance rates of −1.02 ± 0.21 and −1.06 ± 0.14 m w.e. yr −1 respectively, which is in agreement with earlier studies. Contrasting glacier responses are observed, with individual glacier mass balance rates ranging from −0.15 to −2.30 m w.e. yr −1 (standard deviation = 0.49 m w.e. yr −1 ; N = 38). For individual glaciers, the two methods agree within error bars, except for small glaciers poorly sampled in the SPOT5 DEM due to clouds. Importantly, our study confirms the lack of penetration of the C-band SRTM radar signal into the NPI snow and firn except for a region above 2,900 m a.s.l. covering <1% of the total area. Ignoring penetration would bias the mass balance by only 0.005 m w.e. yr −1 . A strong advantage of the ASTER method is that it relies only on freely available data and can thus be extended to other glacierized areas.

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“…Of 69 major outlet glaciers in the region, 49 flow into lakes and the rest flow into the ocean (Warren and Aniya, 1999). Most of the calving glaciers have been retreating over the last several decades (Aniya et al, 1997;Rignot et al, 2003;Masiokas et al, 2009;Lopez et al, 2010) as a result of warming climate (e.g., Lopez et al, 2010;Schaefer et al, 2015). For example, Glaciar Upsala, a freshwater calving glacier in the Southern Patagonia Icefield (SPI), has been retreating and thinning since 2008, at rates significantly greater than those of other glaciers in Patagonia (Muto and Furuya, 2013;Sakakibara et al, 2013;Sakakibara and Sugiyama, 2014), and mass loss from this glacier accounted for about 15% of the total mass loss from the SPI between 2000 and 2012 (Willis et al, 2012).…”

Section: Introductionmentioning

confidence: 99%

Seasonal Variations in Ice-Front Position Controlled by Frontal Ablation at Glaciar Perito Moreno, the Southern Patagonia Icefield

et al. 2017

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The front position of calving glaciers is controlled by ice speed and frontal ablation which consists of the two processes of calving and subaqueous melting. However, the relative importance of these processes in frontal variation is difficult to assess and poorly understood, particularly for freshwater calving glaciers. To better understand the mechanism of seasonal variations involved in the ice front variations of freshwater calving glaciers, we measured front position, ice surface speed, air temperature, and proglacial lakewater temperature of Glaciar Perito Moreno in Patagonia. No substantial fluctuations in front position and ice speed occurred during the 15-year period studied (1999)(2000)(2001)(2002)(2003)(2004)(2005)(2006)(2007)(2008)(2009)(2010)(2011)(2012)(2013), despite a warming trend in air temperature (0.059 • C a −1 ). Seasonal variations were observed both in the ice-front position (±50 m) and ice speed (±15%). The frontal ablation rate, computed from the frontal displacement rate and the ice speed, varied in a seasonal manner with an amplitude approximately five times greater than that in the ice speed. The frontal ablation correlated well with seasonal lakewater temperature variations (r = 0.96) rather than with air temperature (r = 0.86). Our findings indicate that the seasonal ice front variations of Glaciar Perito Moreno are primarily due to frontal ablation, which is controlled through subaqueous melting by the thermal conditions of the lake.

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Quantifying mass balance processes on the Southern Patagonia Icefield

Cited by 80 publications

References 40 publications

Recent geodetic mass balance of Monte Tronador glaciers, northern Patagonian Andes

Recent geodetic mass balance of Monte Tronador glaciers, northern Patagonian Andes

Geodetic Mass Balance of the Northern Patagonian Icefield from 2000 to 2012 Using Two Independent Methods

Seasonal Variations in Ice-Front Position Controlled by Frontal Ablation at Glaciar Perito Moreno, the Southern Patagonia Icefield

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