Little Ice Age advance and retreat of Glaciar Jorge Montt, Chilean Patagonia

Rivera, Andrés; Koppes, Michèle; Bravo, Claudio; Aravena, Juan Carlos

doi:10.5194/cp-8-403-2012

Cited by 51 publications

(59 citation statements)

References 34 publications

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“…West of SPI typical maritime influence with small seasonal but high annual variations is observed, whereas east of SPI more continental climate with larger temperature fluctuation during the year prevails (Rosenblüth et al, 1995). Minimum temperatures for the period 1961-2006 show a slight warming south of 47 • S and a cooling of 0.04 to 0.18 • C per 10 yr between 40 and 47 • S. Most of these tendencies were attributed to the 1976/77 climate shift (Carrasco et al, 2008).…”

Section: Introductionmentioning

confidence: 96%

“…Considering recent warming in Southern Patagonia and the Antarctic Peninsula it is important to understand glacier variations and their responses to climate change (Cook et al, 2005;Rosenblüth et al, 1995;Thomas et al, 2009). A quick response to climate change is expected for glaciers with high accumulation and ablation rates (Oerlemans and Fortuin, 1992).…”

Section: Introductionmentioning

confidence: 99%

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Net accumulation rates derived from ice core stable isotope records of Pío XI glacier, Southern Patagonia Icefield

et al. 2013

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Abstract. Pío XI, the largest glacier of the Southern Patagonia Icefield, reached its neoglacial maximum extent in 1994 and is one of the few glaciers in that area which is not retreating. In view of the recent warming it is important to understand glacier responses to climate changes. Due to its remoteness and the harsh conditions in Patagonia, no systematic mass balance studies have been performed. In this study we derived net accumulation rates for the period 2000-2006 from a 50 m (33.2 4 m weq) ice core collected in the accumulation area of Pío XI (2600 m a.s.l., 49 • 16 40 S, 73 • 21 14 W). Borehole temperatures indicate near temperate ice, but the average melt percent is only 16 ± 14%. Records of stable isotopes are well preserved and were used for identification of annual layers. Net accumulation rates range from 3.4-7.1 water equivalent (m weq) with an average of 5.8 m weq, comparable to precipitation amounts at the Chilean coast, but not as high as expected for the Icefield. Ice core stable isotope data correlate well with upper air temperatures and may be used as temperature proxy.

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Section: Introductionmentioning

confidence: 96%

Section: Introductionmentioning

confidence: 99%

Net accumulation rates derived from ice core stable isotope records of Pío XI glacier, Southern Patagonia Icefield

et al. 2013

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“…Rapid retreat and speed-up have been observed at numerous calving glaciers in Greenland (e.g., Howat et al, 2005;Amundson et al, 2008;Moon et al, 2012Moon et al, , 2015, Alaska (e.g., Meier and Post, 1987;Boyce et al, 2007;McNabb and Hock, 2014) and Patagonia (e.g., Naruse and Skvarca, 2000;Rivera et al, 2012;Sakakibara et al, 2013;Sakakibara and Sugiyama, 2014). The rapid changes take place when a glacier terminus retreats from a bedrock rise into deeper water along a reversed bed slope (e.g., Howat et al, 2005).…”

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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“…On calving glaciers, the velocities can reach a maximum at the glacier front, due to the pulling effect of high calving rates. These high rates can be enhanced when near buoyancy conditions at the front are reached by a glacier calving into deep waters (Rivera et al, 2012). Very little is known about the ice flow velocities near the front of Viedma glacier, and about the ice-lake interactions taking place in this place.…”

Section: Results: Motion Detection Processesmentioning

confidence: 99%

Optical Flow Applied to Time-Lapse Image Series to Estimate Glacier Motion in the Southern Patagonia Ice Field

Lannutti¹,

Lenzano²,

Toth³

et al. 2016

Int. Arch. Photogramm. Remote Sens. Spatial Inf. Sci.

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ABSTRACT:In this work, we assessed the feasibility of using optical flow to obtain the motion estimation of a glacier. In general, former investigations used to detect glacier changes involve solutions that require repeated observations which are many times based on extensive field work. Taking into account glaciers are usually located in geographically complex and hard to access areas, deploying time-lapse imaging sensors, optical flow may provide an efficient solution at good spatial and temporal resolution to describe mass motion. Several studies in computer vision and image processing community have used this method to detect large displacements. Therefore, we carried out a test of the proposed Large Displacement Optical Flow method at the Viedma Glacier, located at South Patagonia Icefield, Argentina. We collected monoscopic terrestrial time-lapse imagery, acquired by a calibrated camera at every 24 hour from April 2014 until April 2015. A filter based on temporal correlation and RGB color discretization between the images was applied to minimize errors related to changes in lighting, shadows, clouds and snow. This selection allowed discarding images that do not follow a sequence of similarity. Our results show a flow field in the direction of the glacier movement with acceleration in the terminus. We analyzed the errors between image pairs, and the matching generally appears to be adequate, although some areas show random gross errors related to the presence of changes in lighting. The proposed technique allowed the determination of glacier motion during one year, providing accurate and reliable motion data for subsequent analysis.

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Little Ice Age advance and retreat of Glaciar Jorge Montt, Chilean Patagonia

Cited by 51 publications

References 34 publications

Net accumulation rates derived from ice core stable isotope records of Pío XI glacier, Southern Patagonia Icefield

Net accumulation rates derived from ice core stable isotope records of Pío XI glacier, Southern Patagonia Icefield

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

Optical Flow Applied to Time-Lapse Image Series to Estimate Glacier Motion in the Southern Patagonia Ice Field

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