4 results on '"Pedro Skvarca"'
Search Results
2. Little Ice Age advances of Glaciar Perito Moreno, Hielo Patagónico Sur, South America
- Author
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Masamu Aniya and Pedro Skvarca
- Subjects
geography ,geography.geographical_feature_category ,Ice field ,Glacier ,Physical geography ,Little ice age ,Geology ,Earth-Surface Processes - Abstract
Glaciar Perito Moreno, with an area of 258km², is located on the eastern side of the Hielo Patagonico Sur (Southern Patagonia Icefield) at about 50°29′S and 73°04′W. Currently, it terminates in Lago Argentino, thereby dividing the lake into Canal de los Tmpanos to the north and Brazo Rico to the south. The glacier has repeatedly made small advances and retreats in the 20th century; however, it can be regarded as rather stable since the 1920. Based on 14C dating of 22 wood and one organic samples, we inferred that Glaciar Perito Moreno made two Little Ice Age (LIA) advances, one at ca. AD 1650 and the other about AD 1820-50. These two dates fit very well into the general framework of the LIA of the HPS.
- Published
- 2012
- Full Text
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3. Glaciological Research Project in Patagonia 2006-2009
- Author
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Gonzalo Barcaza, Hiroyuki Enomoto, Sebastián Marinsek, Masamu Aniya, Nozomu Naito, Pedro Skvarca, Keiko Konya, Kenta Tone, Shun Tsutaki, Ryo Anma, Kazuaki Hori, Shin Sugiyama, Tatsuto Aoki, Takayuki Nuimura, and Takane Matsumoto
- Subjects
geography ,geography.geographical_feature_category ,Oceanography ,Pleistocene ,Peninsula ,Moraine ,Glacier ,Last Glacial Maximum ,Glacial period ,Debris ,Coring ,Geology ,Earth-Surface Processes - Abstract
The Glaciological Research Project in Patagonia (GRPP) 2006-2009 was carried out with several objectives at Glaciar Perito Moreno of the Hielo Patagonico Sur (HPS), in the area of the Hielo Patagonico Norte (HPN) and along the Pacific coast. At Glaciar Perito Moreno, hot water drilling was carried out at about 5km upstream from the terminus, reaching the glacier bottom at ca. 515m, in order to monitor subglacial water pressure. Good positive correlations among air temperature, subglacial water pressure and glacier flow speed were found. Based on 14C dating of tree and organic samples, it is proposed that Glaciar Perito Moreno made two Little Ice Age (LIA) advances at AD1600-1700 and ca. 130-100y BP (AD1820-50). Fan deltas located at the mouth of big rivers around Lago General Carrera (Buenos Aires) and Lago Cochrane (Pueyrredon), in the area east of the HPN, were investigated to elucidate their development. The variations of 21 outlet glaciers of the HPN elucidated from aerial surveys for 2004/05-2008/09 revealed an areal loss of 8.67km2 in four years. A general slowing down of retreats was observed with a few exceptions. Meteorological measurements at Glaciar Exploradores of the HPN from 2005 to 2009 indicate that air temperature ranged from 17.4°C to -10.5°C. The total annual precipitation was about 3000mm. Glacier surface melt was observed at two spots. Sediment and water discharges from the glacier showed that while water discharge fluctuated a lot, suspended sediment concentration was rather stable in summer. A single channel seismic profiling during the JAMSTEC MR08-06 cruise identified a probable submerged moraine formed before the last glacial maximum (LGM) in the Golfo de Penas, south of Taitao Peninsula. Piston coring along the Chilean coast further indicates that ice-rafted debris recorded the LGM and earlier Late Pleistocene events of the glacial advance.
- Published
- 2011
- Full Text
- View/download PDF
4. Hot-water drilling at Glaciar Perito Moreno, Southern Patagonia Icefield
- Author
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Shin Sugiyama, Sebastián Marinsek, Nozomu Naito, Kenta Tone, Hiroyuki Enomoto, Kunio Shinbori, Masamu Aniya, and Pedro Skvarca
- Subjects
Hydrology ,geography ,geography.geographical_feature_category ,Drilling system ,Borehole ,Ice field ,Drilling ,Ice calving ,borehole ,パタゴニア ,Glacier ,Overburden pressure ,Drainage system (geomorphology) ,Patagonia ,カービング氷河 ,calving glacier ,掘削孔 ,氷河底面水圧 ,熱水掘削 ,subglacial water pressure ,Geomorphology ,Geology ,hot water drilling ,Earth-Surface Processes - Abstract
Glaciar Perito Moreno is one of the major freshwater calving glaciers in the Southern Patagonia Icefield. Its fast-flowing characteristic is probably due to high water pressure at the glacier bed, however, subglacial conditions have never been observed in Patagonia until our recent undertaking. To investigate the role of subglacial water pressure in the calving glacier dynamics, we performed hot-water drilling at Glaciar Perito Moreno from February to March 2010. This study represents the first attempt ever at hot-water glacier drilling in Patagonia. Two boreholes were drilled to the bed at 4.7km upglacier from the terminus, where the ice was revealed to be 515±5m thick and the bed located at about 330m below the proglacial lake level. The water levels in the boreholes were >100m above the lake level, which indicates that more than 90% of the ice overburden pressure was balanced out by the subglacial water pressure. Water in the boreholes had drained away before the drilling reached the bed, suggesting the existence of an englacial drainage system. These results provide crucial information for understanding the hydraulic and hydrological conditions of calving glaciers. In order to drill a 500m deep glacier, an existing hot-water drilling system was adapted by increasing the number of high-pressure hot-water machines. The drilling operation at Glaciar Perito Moreno confirmed the system's capacity to drill a 500-m-deep borehole at a rate of 50mh-1 with fuel consumption rates of 15.7lh-1 for diesel and 3.9lh-1 for petrol.
- Published
- 2010
- Full Text
- View/download PDF
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