K. Konya, T. Kadota, G. Davaa, H. Yabuki, T. Ohata
An observational study was conducted for the first time at the ablation area of Potanin glacier, Tavan Bogd region, in western Mongolia in 2007-2008 in order to understand the meteorological and glaciological features. In the study, annual meteorological data and summer surface ablation data were obtained. It was found that the annual mean temperature was -8.8°C on the glacier, and the surface albedo exhibited altitude dependence. Further, the precipitation measured near the glacier during summer was much larger than that measured at Ulgii. Surface energy balance was calculated by a gradient method; it revealed that shortwave radiation was the dominant heat source of surface ablation, whereas the contribution rate of turbulent heat flux was small. The ablation calculated by an equation constructed using the measured radiation showed fairly good correlations with the observed daily ablation, whereas the degree-day method showed good correlations for cumulative ablation. This study revealed the certain uniqueness of the glacio-climate in this region, and showed the further necessity of analysis on the relation of meteorological conditions and the mass balance of the glacier.
{"title":"Meteorological and ablation features of Potanin Glacier, Mongolian Altai","authors":"K. Konya, T. Kadota, G. Davaa, H. Yabuki, T. Ohata","doi":"10.5331/BGR.28.7","DOIUrl":"https://doi.org/10.5331/BGR.28.7","url":null,"abstract":"An observational study was conducted for the first time at the ablation area of Potanin glacier, Tavan Bogd region, in western Mongolia in 2007-2008 in order to understand the meteorological and glaciological features. In the study, annual meteorological data and summer surface ablation data were obtained. It was found that the annual mean temperature was -8.8°C on the glacier, and the surface albedo exhibited altitude dependence. Further, the precipitation measured near the glacier during summer was much larger than that measured at Ulgii. Surface energy balance was calculated by a gradient method; it revealed that shortwave radiation was the dominant heat source of surface ablation, whereas the contribution rate of turbulent heat flux was small. The ablation calculated by an equation constructed using the measured radiation showed fairly good correlations with the observed daily ablation, whereas the degree-day method showed good correlations for cumulative ablation. This study revealed the certain uniqueness of the glacio-climate in this region, and showed the further necessity of analysis on the relation of meteorological conditions and the mass balance of the glacier.","PeriodicalId":9345,"journal":{"name":"Bulletin of glaciological research","volume":"28 1","pages":"7-16"},"PeriodicalIF":1.0,"publicationDate":"2010-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.5331/BGR.28.7","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71026645","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Sugiyama, P. Skvarca, Nozomu Naito, Kenta Tone, H. Enomoto, Kunio Shinbori, S. Marinsek, M. Aniya
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.
{"title":"Hot-water drilling at Glaciar Perito Moreno, Southern Patagonia Icefield","authors":"S. Sugiyama, P. Skvarca, Nozomu Naito, Kenta Tone, H. Enomoto, Kunio Shinbori, S. Marinsek, M. Aniya","doi":"10.5331/BGR.28.27","DOIUrl":"https://doi.org/10.5331/BGR.28.27","url":null,"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.","PeriodicalId":9345,"journal":{"name":"Bulletin of glaciological research","volume":"28 1","pages":"27-32"},"PeriodicalIF":1.0,"publicationDate":"2010-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71026608","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2004-01-01DOI: 10.14850/JSSI.2004.0.138.0
H. Seddik, S. Sugiyama, R. Naruse
A numerical model for glacial-valley cross-section evolution has been developed. The model allows the simulation of the development of U-shaped valleys by coupling an ice flow model in a transverse section with an erosionmodel. The core of the cross-section development model is the calculation of the two-dimensional flow speed field in a transverse cross-section considering the lateral drag from glacier side walls and the basal-stress dependent sliding speed. Assuming that the glacial erosion is a quadratic function of the sliding speed, the model shows rapid evolution of a V-shaped profile into a recognizable glacial form with sliding velocities ranging from 3 m a - 1 to 8 m a - 1 .
建立了冰谷剖面演化的数值模型。该模型通过将横截面冰流模型与侵蚀模型耦合，可以模拟u型山谷的形成。截面发展模型的核心是考虑冰川侧壁侧向阻力和基底应力相关滑动速度的横向截面内二维流速场的计算。假设冰川侵蚀是滑动速度的二次函数，该模型显示了一个v形剖面快速演变为一个可识别的冰川形式，滑动速度在3 ~ 8 m a - 1之间。
{"title":"Numerical simulation of glacial-valley cross-section evolution","authors":"H. Seddik, S. Sugiyama, R. Naruse","doi":"10.14850/JSSI.2004.0.138.0","DOIUrl":"https://doi.org/10.14850/JSSI.2004.0.138.0","url":null,"abstract":"A numerical model for glacial-valley cross-section evolution has been developed. The model allows the simulation of the development of U-shaped valleys by coupling an ice flow model in a transverse section with an erosionmodel. The core of the cross-section development model is the calculation of the two-dimensional flow speed field in a transverse cross-section considering the lateral drag from glacier side walls and the basal-stress dependent sliding speed. Assuming that the glacial erosion is a quadratic function of the sliding speed, the model shows rapid evolution of a V-shaped profile into a recognizable glacial form with sliding velocities ranging from 3 m a - 1 to 8 m a - 1 .","PeriodicalId":9345,"journal":{"name":"Bulletin of glaciological research","volume":"22 1","pages":"75-79"},"PeriodicalIF":1.0,"publicationDate":"2004-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66719023","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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.
{"title":"Little Ice Age advances of Glaciar Perito Moreno, Hielo Patagónico Sur, South America","authors":"M. Aniya, P. Skvarca","doi":"10.5331/BGR.30.1","DOIUrl":"https://doi.org/10.5331/BGR.30.1","url":null,"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.","PeriodicalId":9345,"journal":{"name":"Bulletin of glaciological research","volume":"30 1","pages":"1-8"},"PeriodicalIF":1.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.5331/BGR.30.1","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71026923","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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