A volcanic ash layer was observed in the 3 ice cores on the Nelson Ice Cap,Antarctica.A comparison of major elemental composition of glass shards from the 3 tephra layers with average whole-rock compositions of 1967-1...A volcanic ash layer was observed in the 3 ice cores on the Nelson Ice Cap,Antarctica.A comparison of major elemental composition of glass shards from the 3 tephra layers with average whole-rock compositions of 1967-1970 eruptions on the Deception Island and of glass shards from other suspected De- ception Island eruptions collected from Antarctic ice and firn indicate that the most reasonable source for the tephra in the Nelson Ice Cap cores is the 1970 eruption on the Deception Island.From the depth of the vol- canic ash layer and measured density profile of the cores,the net accumulation rate at the summit,Core GW,is 1200 g·cm^(-2)·a^(-1) during the past 20 years,and the net accumulation rates are 700 g·cm^(-2)·a^(-1) and 6 g·cm^(-2)·a^(-1) at sites N30 and N50,respectively.In the eastern part of the Nelson Ice Cap,the accu- mulation rate may be higher than that in the northern part,because no volcanic ash in ice cores was observed at similar depths collected from this region.展开更多
基于全球地表水数据集(JRC Global Surface Water,GSW),结合目视解译和质量控制,开展了1980s-2019时段形成和发育的亚洲冰湖最大水域范围(≥0.01km^(2))的空间编目;根据冰湖与冰川的关系,将冰湖分为冰川补给湖(包括:冰上湖、冰川接触湖...基于全球地表水数据集(JRC Global Surface Water,GSW),结合目视解译和质量控制,开展了1980s-2019时段形成和发育的亚洲冰湖最大水域范围(≥0.01km^(2))的空间编目;根据冰湖与冰川的关系,将冰湖分为冰川补给湖(包括:冰上湖、冰川接触湖和冰川不接触湖3个亚类)和非冰川补给湖2类,同时分析了不同类型冰湖的空间分布特征,最终得到亚洲冰川湖泊分类与最大分布数据集(1980s-2019)。研究表明,冰湖总绝对面积误差为98.91km^(2),平均相对误差为19.1%。该数据集包括:(1)空间数据,即1980s-2019年亚洲冰湖最大分布范围与类型数据;(2)表格数据,包括:1980s-2019年亚洲不同大小、类型、高程尺度下冰湖的数量与面积统计。数据集存储为.shp和.xlsx格式,由9个数据文件组成,数据量为21.8MB(压缩为1个文件,4.92 MB)。展开更多
Mountains have been described as the water towers of the world. Almost all major rivers have their sources in mountains; glaciers are important water resources that contribute meltwater to river discharge. Glaciers pa...Mountains have been described as the water towers of the world. Almost all major rivers have their sources in mountains; glaciers are important water resources that contribute meltwater to river discharge. Glaciers participate in the global water cycle and, with their solid water storage, are an important component of the water balance. As solid reservoirs, glaciers continue to receive the mass nourishment of solid precipitation from the atmosphere, and their meltwater feed and regulate fiver discharge. Physical changes in glaciers are an indicator of climate change. Over the past half century, the global temperature has increased by 1-2 ℃, which emphasizes the urgent task of monitoring glaciers and predicting their trend. As an example, we have investigated, researched, and surveyed Glacier No. 1 in the Urumqi River source, Tianshan （abbr. Glacier No. 1 Tianshan or Glacier No.l） for half a century. We have found an increase by degrees of the glacial regression during the last 400 years and discovered a terminal moraine which is forming today. The global temperature is rising continually, while the local glacial temperature is 0.4 times that of the global temperature change. Thus, we forecast that Glacier No. 1 Tianshan will disappear during the late 21 st Century （2074-2100 A.D.）.展开更多
Guxiang and Baiyu Glaciations are two previously recognized local glaciations of the Tibetan Plateau. They have been widely used as the reference standard for classifying Late Quaternary glaciations on the Tibetan Pla...Guxiang and Baiyu Glaciations are two previously recognized local glaciations of the Tibetan Plateau. They have been widely used as the reference standard for classifying Late Quaternary glaciations on the Tibetan Plateau and its surrounding mountains. However, the numerical chronologies of both glaciations have been lacking. In this study, cosmogenic 10Be dating was undertaken to define the timing of these two glaciations. The surface boulders deposited by the glaciers of the Guxiang and Baiyu Glaciations have exposure ages of 112.9±16.7―136.5±15.8 ka BP and 11.1±1.9―18.5±2.2 ka BP, respectively. It is likely that the Guxiang and Baiyu Glaciations correspond to marine isotope stages 6 and 2, respectively.展开更多
基金the National Natural Science Foundation of China the State Committee for Antarctic Research of China
文摘A volcanic ash layer was observed in the 3 ice cores on the Nelson Ice Cap,Antarctica.A comparison of major elemental composition of glass shards from the 3 tephra layers with average whole-rock compositions of 1967-1970 eruptions on the Deception Island and of glass shards from other suspected De- ception Island eruptions collected from Antarctic ice and firn indicate that the most reasonable source for the tephra in the Nelson Ice Cap cores is the 1970 eruption on the Deception Island.From the depth of the vol- canic ash layer and measured density profile of the cores,the net accumulation rate at the summit,Core GW,is 1200 g·cm^(-2)·a^(-1) during the past 20 years,and the net accumulation rates are 700 g·cm^(-2)·a^(-1) and 6 g·cm^(-2)·a^(-1) at sites N30 and N50,respectively.In the eastern part of the Nelson Ice Cap,the accu- mulation rate may be higher than that in the northern part,because no volcanic ash in ice cores was observed at similar depths collected from this region.
文摘基于全球地表水数据集(JRC Global Surface Water,GSW),结合目视解译和质量控制,开展了1980s-2019时段形成和发育的亚洲冰湖最大水域范围(≥0.01km^(2))的空间编目;根据冰湖与冰川的关系,将冰湖分为冰川补给湖(包括:冰上湖、冰川接触湖和冰川不接触湖3个亚类)和非冰川补给湖2类,同时分析了不同类型冰湖的空间分布特征,最终得到亚洲冰川湖泊分类与最大分布数据集(1980s-2019)。研究表明,冰湖总绝对面积误差为98.91km^(2),平均相对误差为19.1%。该数据集包括:(1)空间数据,即1980s-2019年亚洲冰湖最大分布范围与类型数据;(2)表格数据,包括:1980s-2019年亚洲不同大小、类型、高程尺度下冰湖的数量与面积统计。数据集存储为.shp和.xlsx格式,由9个数据文件组成,数据量为21.8MB(压缩为1个文件,4.92 MB)。
基金supported by The State Key Science Research Programme for Global Change Research of China (Grant No.2010CB951402)State Key Laboratory of Cryospheric Sciences Fund (SKLCS 2010-04)+1 种基金the State Key Basic Research Development Program of China (973 Program)(Grant No.2007 CB411507)the National Natural Science Foundation of China (Grant No. 40771047)
文摘Mountains have been described as the water towers of the world. Almost all major rivers have their sources in mountains; glaciers are important water resources that contribute meltwater to river discharge. Glaciers participate in the global water cycle and, with their solid water storage, are an important component of the water balance. As solid reservoirs, glaciers continue to receive the mass nourishment of solid precipitation from the atmosphere, and their meltwater feed and regulate fiver discharge. Physical changes in glaciers are an indicator of climate change. Over the past half century, the global temperature has increased by 1-2 ℃, which emphasizes the urgent task of monitoring glaciers and predicting their trend. As an example, we have investigated, researched, and surveyed Glacier No. 1 in the Urumqi River source, Tianshan （abbr. Glacier No. 1 Tianshan or Glacier No.l） for half a century. We have found an increase by degrees of the glacial regression during the last 400 years and discovered a terminal moraine which is forming today. The global temperature is rising continually, while the local glacial temperature is 0.4 times that of the global temperature change. Thus, we forecast that Glacier No. 1 Tianshan will disappear during the late 21 st Century （2074-2100 A.D.）.
基金Supported by the National Natural Science Foundation of China (Grant Nos. 40371013 and 40601012)NSF/EAR-0345277
文摘Guxiang and Baiyu Glaciations are two previously recognized local glaciations of the Tibetan Plateau. They have been widely used as the reference standard for classifying Late Quaternary glaciations on the Tibetan Plateau and its surrounding mountains. However, the numerical chronologies of both glaciations have been lacking. In this study, cosmogenic 10Be dating was undertaken to define the timing of these two glaciations. The surface boulders deposited by the glaciers of the Guxiang and Baiyu Glaciations have exposure ages of 112.9±16.7―136.5±15.8 ka BP and 11.1±1.9―18.5±2.2 ka BP, respectively. It is likely that the Guxiang and Baiyu Glaciations correspond to marine isotope stages 6 and 2, respectively.
