Last glaciation and maximum glaciation in the Qinghai-Xizang (Tibet) Plateau: A controversy to M. Kuhle’s ice sheet hypothesis     

Yafeng Shi  Benxing Zheng  Shijie Li 《中国地理科学(英文版)》1992,2(4):293-311

Since the late 1950’s, many Chinese scientists have explored the remains of the Quaternary glaciation in the Qinghai-Xizang (Tibet) Plateau and its surrounding mountains. In the main, 3–4 glaciations have been recognized. The largest one occurred in the Late Middle Pleistocene with piedmont glaciers, ice caps and trellis valley glaciers in many high peak regions. But here is no evidence of a unified ice sheet covering the whole plateau as described by M. Kuhle. Due to the further uplifting of the Himalayas and Qinghai-Xizang Plateau the climate became progressively driver, diminishing the extension of glaciers during the Late Pleistocene. The elevation of the snow line during the Last Glaciation was about 4,000 m on the south, east and northeast edges of the plateau and ascended to 5500 m on the hinder northwest of the plateau. The thermal effect of the big plateau massif, the sharp increase of aridity from the southeast rim to the northwest inland area and the abrupt decrease of precipitation during the Ice Age largely account for the distribution of the Quaternary glaciers in the Qinghai-Xizang Plateau. The neglect of Chinese literature may be one of the causes accounting for M. Kuhle’s misinterpretation on the environment of the Quaternary glaciations in the Qinghai-Xizang Plateau.  相似文献   

Recent variations of supraglacial lakes on the Baltoro Glacier in the central Karakoram Himalaya and its possible teleconnections with the pacific decadal oscillation     

Bijeesh Kozhikkodan Veettil  Nilceia Bianchini  Ulisses Franz Bremer  Éder Leandro Bayer Maier  Jefferson Cardia Simões 《国际地球制图》2016,31(1):109-119

This study discusses the formation and variations of supraglacial lakes on the Baltoro glacier system in the central Karakoram Himalaya during the last four decades. We mapped supraglacial lakes on the Baltoro Glacier from 1978 to 2014 using Landsat MSS, TM, ETM + and LCDM images. Most of the glacial lakes were formed or expanded during the late 1970s–2008. After 2008, the total number and the area of glacial lakes were found to be lesser compared to previous years. We tried to find any teleconnections exists between the glacial lake changes in this region and the pacific decadal oscillation (PDO), which entered its prolonged warm regime in the late 1970s and again to its cold regime in 2008, based on observational investigation. The decrease in the number and area of the supraglacial lakes after 2008 is hypothesised to be linked with the recent cold phase of PDO.  相似文献   

The seasonal circulation of the Glacier Bay, Alaska fjord system     

J.B. Matthews   《Estuarine, Coastal and Shelf Science》1981,12(6)

  相似文献   

Interpreting exposure ages from ice‐cored moraines: a Neoglacial case study on Baffin Island,Arctic Canada     

《第四纪科学杂志》2017,32(8):1049-1062

  相似文献   

Climate evolution and forcing during the last 40 ka from the oscillations in Apennine glaciers and high mountain lakes,Italy     

《第四纪科学杂志》2017,32(8):1085-1098

  相似文献   

Rock glaciers in the northern Japanese Alps: palaeoenvironmental implications since the Late Glacial     

Masafumi Aoyama 《第四纪科学杂志》2005,20(5):471-484

In order to determine the palaeoclimatic and palaeo‐permafrost conditions in the northern Japanese Alps in central Japan, the ages of rock glaciers were investigated by relative age dating techniques such as weathering‐rind thickness and Schmidt hammer measurements. The results of the relative age dating suggest that the formation of the investigated rock glaciers may have started during the early phase of the Late Glacial or around the onset of the Holocene. The lower limit of current discontinuous permafrost in the northern Japanese Alps, which is indicated by the terminus of the lowest active/inactive rock glacier, lies at 2530 m a.s.l., while that of discontinuous permafrost during the Late Glacial or early phase of the Holocene, which is indicated by the terminus of the lowest relict rock glacier, lies at 2220 m a.s.l. Therefore, the lower limit of discontinuous permafrost during these periods would have been at least about 300 m lower than that of the current discontinuous permafrost. Climatic and geomorphological conditions during the Late Glacial led to a change in the environment from a glacial environment to a periglacial (permafrost) environment in the current alpine zone of the northern Japanese Alps. A large number of cirques were deglaciated and several of them were occupied by active rock glaciers around the onset of the Holocene. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   

Glacier retreat and its effect on stream flow in the source region of the Yangtze River     

Shanshan Wu  Zhijun Yao  Heqing Huang  Zhaofei Liu  Yuansheng Chen 《地理学报(英文版)》2013,23(5):849-859

There is growing concern over the effects of climate change on glacier melt and hydrology. In this article, we used two natural small-scale basins, Tuotuo River and Buqu River in the source region of the Yangtze River, China, to show the impacts of glacier melt on stream flow. Changes in the extent of glaciers and ice volume in 1970, 1992 and 2009 are evaluated using remote sensing images. Changes to the glacier surface area over the same time interval are estimated through the delineation of glacier outlines and positions using Landsat TM/ETM＋ imagery. By 2009, the glacier surface area had decreased by 20.83% and 34.81% of the 1970 values in Tuotuo River and Baqu River basins respectively. The total meltwater supply in each basin is estimated to be 2.56×10^9 m^3/yr and 1.24×10^9 m^3/yr respectively. Mass balance calculations show that glaciers in the study area suffered a constant mass loss of snow and ice, accumulatively approximately -24 m over the past 40 years. The annual and summer stream flow tended to increase in Tuotuo River basin from 1970 to 2009 while a negative trend of change was shown in Buqu River basin during 1970-1986. Glaciers became shorter, narrower and thinner under the effect of atmospheric warming. Streamflow increase has been recorded at Tuotuo River station in response to increased glacier and permafrost melt. However, streamflow decrease has been recorded at Yanshiping station on Buqu River, where glacier melt has lagged behind atmospheric warming. These results show a close but variable linkage among climate change, glacier melting and water resources in the source region of the Yangtze River.  相似文献   

基于RS的林芝-加查段泥石流源地信息提取     

王高峰  唐川  高幼龙  李为乐 《地理空间信息》2012,(3):61-63

为研究泥石流灾害对西藏雅鲁藏布江林芝-加查段沿线的影响与危害,基于遥感手段开展了林芝-加查段沿线泥石流源地物源及冰川水文信息特征的提取研究与分析。研究结果表明:林芝-加查段沿线泥石流源地物源分布具有不均匀性;源地冰川分布具有不平衡性;沿线泥石流源地的物源在冰川融水及冰川型泥石流过后更加发育,积累的松散物质更加丰富,导致泥石流源地物源进一步复活并产生大量新物源,从而使沿线泥石流发生频率增高,规模增大。  相似文献   

LICHENOMETRIC AGES OF THE LITTLE ICE AGE MORAINES ON KING GEORGE ISLAND AND OF THE LAST VOLCANIC ACTIVITY ON PENGUIN ISLAND (WEST ANTARCTICA)     

PIOTR JAN ANGIEL  MACIEJ DĄBSKI 《Geografiska Annaler: Series A, Physical Geography》2012,94(3):395-412

The recently observed recession of glaciers on King George Island is associated with decades of climate warming in the Antarctic Peninsula region. However, with only 60 years of glaciological observations in the study area ages of the oldest moraines are still uncertain. The goal of the study was to estimate ages of lichen colonization on the oldest moraines of the Ecology and White Eagle Glaciers on King George Island and on the Principal Cone of Penguin Island volcano. The first lichenometric studies on these islands from the late 1970s used rates that had about four to five times slower Rhizocarpon growth rates. We re‐examined the sites and measured 996 thalli diameters to establish the surface ages. To estimate the age we used (1) long‐term Rhizocarpon lichen group growth rates established by authors using data from a previous lichenometric study on King George Island, and (2) previous data of lichen growth rates from other sub‐Antarctic islands. Our results suggest growth rates between 0.5 and 0.8 mm yr^–1. According to these rates the ages of the oldest moraine ridges are of the Little Ice Age and were colonized at the beginning of the twentieth century. The mid‐twentieth century age of lichen colonization on the historically active Penguin Island volcano might support the date of the last eruption reported by whalers in the end of the nineteenth and the beginning of the twentieth century.  相似文献   

2050年前气候变暖冰川萎缩对水资源影响情景预估   总被引：42，自引：34，他引：42  

施雅风 《冰川冻土》2001,23(4):333-341

根据有不确定性的综合预测 ,到 2 0 5 0年左右青藏高原温度可比 2 0世纪末升高 2 .5℃左右 ,其导致冰川强烈消融的夏季升温为 1.4℃ ,将使平衡线上升 10 0m以上 .冰舌区消融冰量超过积累区冰运动来的冰量 ,冰川出现变薄后退 ,初期以变薄为主融水量增加 ,后期冰川面积大幅度减少 ,融水量衰退 ,至冰川消亡而停止 .考虑冰川大小 ,冰川类型响应气候变暖的敏感性有重大差别 ,应用新编中国冰川目录的统计数据 ,选择若干区域 ,预估 2 0 5 0年前冰川萎缩对水资源影响情景 .祁连山北麓河西地区 ,天山北麓准噶尔盆地南缘 ,天山南麓吐鲁番 哈密盆地的多数出山河流的冰川 ,以面积小于 2km2 者占绝对优势 ,对气候变暖最为敏感 ,衰退迅速 ,本世纪初期出现融水量高峰 ,中期融水量减少 ,对每条河流的影响以 10 6～ 10 7m3 ·a-1计 .少数流域如疏勒河、玛纳斯河等 ,冰川融水量占河川径流 1/ 3以上 ,有若干 5～ 30km2 左右中等规模冰川存在 ,预期至本世纪中期才出现融水高峰 ,融水增加值以 10 8m3 ·a-1计 .塔里木盆地周围高山冰川总面积达 2 2 0 0 9km2 ,有面积超过 10 0km2 、冰舌为厚表覆盖的大冰川 2 2条 ,退缩缓慢 ,冰川融水量在叶尔羌河、玉龙喀什河与阿克苏河等占 5 0 %～ 80 % .现在塔里木河干流主要靠天山西南部  相似文献