The glaciers Austre Lovenbreen and Pedersenbreen are located at Ny-（？）lesund. Svalbard.The surface mass balance and ice flow velocity of both glaciers have been determined from the first year of observations（2005/...The glaciers Austre Lovenbreen and Pedersenbreen are located at Ny-（？）lesund. Svalbard.The surface mass balance and ice flow velocity of both glaciers have been determined from the first year of observations（2005/2006）.while the front edge of Austre Lovenbreen was also surveyed.The results are as follows： （1） The net mass balances of Austre Lovenbreen and Pedersenbreen are—0.44 and—0.20 m w.e.,the annual ablation is—0.99 and—0.91 m w.e.. and the corresponding equilibrium line altitudes are 178.10 and 494.87 m.respectively. （2） Austre Lovenbreen and Pedersenbreen are characterized as ice flow models of surge-type glaciers in Svalbard.The horizontal vectors of the ice flow velocities are parallel or converge to the central lines of both glaciers,with lower velocities in the lower ablation areas and higher velocities in the middle and upper reaches of the glaciers.The vertical vectors of ice flow velocities show that there is a mass loss in the ablation areas,which reduces with increasing altitude, while there is a mass gain near the equilibrium line of Austre Lovenbreen.（3） The front edge of Austre Lovenbreen receded at an average rate of 21.83 m·a^（-1）,with remarkable variability-a maximum rate of 77.30 m·a^（-1） and a minimum rate of 2.76 m·a^（-1）.展开更多
Glacier-related mass flows(GMFs)in the high-mountain cryosphere have become more frequent in the last decade,e.g.,the 2018 Sedongpu(SDP)GMFs in the Himalayas.Seismic forcing,thermal perturbation and heavy rainfall are...Glacier-related mass flows(GMFs)in the high-mountain cryosphere have become more frequent in the last decade,e.g.,the 2018 Sedongpu(SDP)GMFs in the Himalayas.Seismic forcing,thermal perturbation and heavy rainfall are common triggers of the GMFs.But the exact role of seimic forcing in the GMF formation is poorly known due to scarity of observational data of real cases.Here the evolution processes of the GMFs and the detachment of the trunk glacier in SDP are reconstructed by using remote sensing techniques,including feature-tracking of multi-source optical satellite imagery and visual interpretation.The reconstruction demonstrates that the high frequency of GMF events in SDP after the Milin earthquake on 18 November 2017 was mainly attributed to the earthquake-induced glacial stress changes and destablisation.The post-earthquake velocity of the trunk glacier is about three times of that in December 2016 and December 2017.The median glacier-surface velocity raised to 0.32 m d-1between November 2017 and June 2018,being 14%-77%higher than that of pre-earthquake,which is initiated by the seismic forcing and then aggravated by additional loading of ice/rock avalanches,infiltration of liquid water,progressively crevassed glacier,and local compressional deformation.Ensuing surge motion of the trunk glacier resulted from high temperature and heavy precipitation between July and September 2018.We infer that the trunk glacier is more sensitive to the thermal perturbation after the Milin earthquake,which is the predominant cause in sudden surge movement.These findings reveal comprehensive mechanisms of quakeinduced,low-angle,glacial detachment and multisource-driven GMF in the Himalayas.展开更多
The accumulation and ablation of a glacier directly reflect its mass income and wastage, and ice temperature indicates glacier＇s climatic and dynamic conditions. Glaciological studies at Baishui Glacier No.1 in Mt. Y...The accumulation and ablation of a glacier directly reflect its mass income and wastage, and ice temperature indicates glacier＇s climatic and dynamic conditions. Glaciological studies at Baishui Glacier No.1 in Mt. Yulong are important for estimating recent changes of the cryosphere in Hengduan Mountains. Increased glacier ablation and higher ice temperatures can cause the incidents of icefall. Therefore, it is important to conduct the study of glacier mass balance and ice temperature, but there are few studies in relation to glacier＇s mass balance and active-layer temperature in China＇s monsoonal temperate glacier region. Based on the field observations of mass balance and glacier temperature at Baishui Glacier No.1, its accumulation, ablation, net balance and near-surface ice temperature structure were analyzed and studied in this paper. Results showed that the accumulation period was ranged from October to the following mid-May, and the ablation period occurred from mid-May to October, suggesting that the ablation period of temperate glacier began about 15 days earlier than that of continental glaciers, while the accumulation period began about 15 days later. The glacier ablation rate was 6.47 cm d 1 at an elevation of 4600 m between June 23 and August 30, and it was 7.4 cm d 1 at 4800 m between June 26 and July 11 in 1982, moreover, they respectively increased to 9.2 cm d 1 and 10.8 cm d 1 in the corresponding period and altitude in 2009, indicating that glacier ablation has greatly intensified in the past years. The temperature of the main glacier body was close to melting point in summer, and it dropped from the glacier surface and reached a minimum value at a depth of 4-6 m in the ablation zone. The temperature then rose to around melting point with the depth increment. In winter, the ice temperature rose gradually with the increasing depth, and close to melting point at the depth of 10 m. Compared with the data from 1982, the glacier temperature has risen in the ablation zone in recent decades.展开更多
Since it is the largest glacier system in Antarctica, the Lambert Glacier basin plays an important role in the mass balance of the overall Antarctic ice sheet. The observed data and shallow core studies from the inlan...Since it is the largest glacier system in Antarctica, the Lambert Glacier basin plays an important role in the mass balance of the overall Antarctic ice sheet. The observed data and shallow core studies from the inland traverse investigations in recent years show that there are noticeable differences in the distribution and variability of the snow accumulation rate between east and west sides. On the east side, the accumulation is higher on the average and has increased in the past decades, while on the west side it is contrary. The ice movement measurement and the ice flux calculation indicate that the ice velocity and the flux are larger in east than in west, meaning that the major part of mass supply for the glacier is from the east side. The mass budget estimate with the latest data gives that the integrated accumulation over the upstream area of the investigation traverse route is larger than the outflow ice flux by 13%, suggesting that the glacier basin is in a positive mass balance state and the ice thickness will increase if the present climate is keeping.展开更多
文摘The glaciers Austre Lovenbreen and Pedersenbreen are located at Ny-（？）lesund. Svalbard.The surface mass balance and ice flow velocity of both glaciers have been determined from the first year of observations（2005/2006）.while the front edge of Austre Lovenbreen was also surveyed.The results are as follows： （1） The net mass balances of Austre Lovenbreen and Pedersenbreen are—0.44 and—0.20 m w.e.,the annual ablation is—0.99 and—0.91 m w.e.. and the corresponding equilibrium line altitudes are 178.10 and 494.87 m.respectively. （2） Austre Lovenbreen and Pedersenbreen are characterized as ice flow models of surge-type glaciers in Svalbard.The horizontal vectors of the ice flow velocities are parallel or converge to the central lines of both glaciers,with lower velocities in the lower ablation areas and higher velocities in the middle and upper reaches of the glaciers.The vertical vectors of ice flow velocities show that there is a mass loss in the ablation areas,which reduces with increasing altitude, while there is a mass gain near the equilibrium line of Austre Lovenbreen.（3） The front edge of Austre Lovenbreen receded at an average rate of 21.83 m·a^（-1）,with remarkable variability-a maximum rate of 77.30 m·a^（-1） and a minimum rate of 2.76 m·a^（-1）.
基金funded by National Key R&D Program of China(Grant 2018YFC1505204)the Second Tibetan Plateau Scientific Expedition and Research Program(2019QZKK0902)+1 种基金the National Key R&D Program of China(2020YFD1100701)the National Natural Science Foundation of China(91747207)。
文摘Glacier-related mass flows(GMFs)in the high-mountain cryosphere have become more frequent in the last decade,e.g.,the 2018 Sedongpu(SDP)GMFs in the Himalayas.Seismic forcing,thermal perturbation and heavy rainfall are common triggers of the GMFs.But the exact role of seimic forcing in the GMF formation is poorly known due to scarity of observational data of real cases.Here the evolution processes of the GMFs and the detachment of the trunk glacier in SDP are reconstructed by using remote sensing techniques,including feature-tracking of multi-source optical satellite imagery and visual interpretation.The reconstruction demonstrates that the high frequency of GMF events in SDP after the Milin earthquake on 18 November 2017 was mainly attributed to the earthquake-induced glacial stress changes and destablisation.The post-earthquake velocity of the trunk glacier is about three times of that in December 2016 and December 2017.The median glacier-surface velocity raised to 0.32 m d-1between November 2017 and June 2018,being 14%-77%higher than that of pre-earthquake,which is initiated by the seismic forcing and then aggravated by additional loading of ice/rock avalanches,infiltration of liquid water,progressively crevassed glacier,and local compressional deformation.Ensuing surge motion of the trunk glacier resulted from high temperature and heavy precipitation between July and September 2018.We infer that the trunk glacier is more sensitive to the thermal perturbation after the Milin earthquake,which is the predominant cause in sudden surge movement.These findings reveal comprehensive mechanisms of quakeinduced,low-angle,glacial detachment and multisource-driven GMF in the Himalayas.
基金National Natural Science Foundation of China,No.40971019No.41273010 The Foundation from the State Key Laboratory of Cryosphere Science,No.SKLCS-ZZ-2012-01-02
文摘The accumulation and ablation of a glacier directly reflect its mass income and wastage, and ice temperature indicates glacier＇s climatic and dynamic conditions. Glaciological studies at Baishui Glacier No.1 in Mt. Yulong are important for estimating recent changes of the cryosphere in Hengduan Mountains. Increased glacier ablation and higher ice temperatures can cause the incidents of icefall. Therefore, it is important to conduct the study of glacier mass balance and ice temperature, but there are few studies in relation to glacier＇s mass balance and active-layer temperature in China＇s monsoonal temperate glacier region. Based on the field observations of mass balance and glacier temperature at Baishui Glacier No.1, its accumulation, ablation, net balance and near-surface ice temperature structure were analyzed and studied in this paper. Results showed that the accumulation period was ranged from October to the following mid-May, and the ablation period occurred from mid-May to October, suggesting that the ablation period of temperate glacier began about 15 days earlier than that of continental glaciers, while the accumulation period began about 15 days later. The glacier ablation rate was 6.47 cm d 1 at an elevation of 4600 m between June 23 and August 30, and it was 7.4 cm d 1 at 4800 m between June 26 and July 11 in 1982, moreover, they respectively increased to 9.2 cm d 1 and 10.8 cm d 1 in the corresponding period and altitude in 2009, indicating that glacier ablation has greatly intensified in the past years. The temperature of the main glacier body was close to melting point in summer, and it dropped from the glacier surface and reached a minimum value at a depth of 4-6 m in the ablation zone. The temperature then rose to around melting point with the depth increment. In winter, the ice temperature rose gradually with the increasing depth, and close to melting point at the depth of 10 m. Compared with the data from 1982, the glacier temperature has risen in the ablation zone in recent decades.
基金This work was supported by the Chinese Academy of Sciences (Grant No. KZCX2-303),the Ministry of Science and Technology of China (Grant No. 2001DIA50040) +1 种基金 the National Natural Science Foundation of China (Grant Nos. 49971021 and 40071025) We tha
文摘Since it is the largest glacier system in Antarctica, the Lambert Glacier basin plays an important role in the mass balance of the overall Antarctic ice sheet. The observed data and shallow core studies from the inland traverse investigations in recent years show that there are noticeable differences in the distribution and variability of the snow accumulation rate between east and west sides. On the east side, the accumulation is higher on the average and has increased in the past decades, while on the west side it is contrary. The ice movement measurement and the ice flux calculation indicate that the ice velocity and the flux are larger in east than in west, meaning that the major part of mass supply for the glacier is from the east side. The mass budget estimate with the latest data gives that the integrated accumulation over the upstream area of the investigation traverse route is larger than the outflow ice flux by 13%, suggesting that the glacier basin is in a positive mass balance state and the ice thickness will increase if the present climate is keeping.
