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411.
对2004年获取的天山奎屯河哈希勒根51号冰川1个雪坑和哈密庙尔沟平顶冰川4个雪坑的离子浓度特征进行了研究,结果表明:Ca2+、NO-3和SO42-是哈密庙尔沟平顶冰川雪坑雪层和积累区雪坑底部冰中的主要离子(尤其是Ca2+ ),其雪层中的主要阳离子关系可在底部冰中得以较好的反映,但雪层中各离子浓度与海拔的相关性不明显,可能与海拔的跨度较小和挖取的雪坑较疏有关;雪坑底部冰中的离子浓度与海拔间明显的相关性说明淋融作用随着海拔升高、气温降低而逐渐减弱。SO42-和Ca2+是奎屯河哈希勒根51号冰川雪坑中的主要离子(尤其是SO42-),其雪坑离子化学特征与哈密庙尔沟平顶冰川差别较大,可能与哈密庙尔沟平顶冰川处于塔克拉玛干沙漠、古尔班通古特沙漠和鄯善沙漠的下风向相关,还可能与雪层内淋融作用的强弱和沉积通量的高程效应有关。哈密庙尔沟平顶冰川积累区雪坑中NH4+、NO3-和K+的Cs/Ci较Ca2+、Mg2+和Na+要大,奎屯河哈希勒根51号冰川Na+和NH4+的“雪冰比”较Cl-、SO42-、Mg2+和Ca2+要大,说明这两条冰川雪坑中的Ca2+和Mg2+信号较其它离子可能更易于在冰芯记录中保存下来,为冰芯研究和古气候记录的恢复提供了保障。  相似文献   
412.
Filtered subglacial meltwater samples were collected daily during the onset of melt (May) and peak melt (July) over the 2011 melt season at the Athabasca Glacier (Alberta, Canada) and analyzed for strontium-87/strontium-86 (87Sr/86Sr) isotopic composition to infer the evolution of subglacial weathering processes. Both the underlying bedrock composition and subglacial water–rock interaction time are the primary influences on meltwater 87Sr/86Sr. The Athabasca Glacier is situated atop Middle Cambrian carbonate bedrock that also contains silicate minerals. The length of time that subglacial meltwater interacts with the underlying bedrock and substrate is a predominant determining factor in solute concentration. Over the course of the melt season, increasing trends in Ca/K and Ca/Mg correspond to overall decreasing trends in 87Sr/86Sr, which indicate a shift in weathering processes from the presence of silicate weathering to primarily carbonate weathering.Early in the melt season, rates of carbonate dissolution slow as meltwater approaches saturation with respect to calcite and dolomite, corresponding to an increase in silicate weathering that includes Sr-rich silicate minerals, and an increase in meltwater 87Sr/86Sr. However, carbonate minerals are preferentially weathered in unsaturated waters. During the warmest part of a melt season the discharged meltwater is under saturated, causing an increase in carbonate weathering and a decrease in the radiogenic Sr signal. Likewise, larger fraction contributions of meltwater from glacial ice corresponds to lower 87Sr/86Sr values, as the meltwater has lower water–rock interaction times in the subglacial system. These results indicate that although weathering of Sr-containing silicate minerals occurs in carbonate dominated glaciated terrains, the continual contribution of new meltwater permits the carbonate weathering signal to dominate.  相似文献   
413.
Glacier advance and recession are considered key indicators of climate change. Understanding the relationship between climatic variations and glacial responses is crucial. Here, we apply archival digital photogrammetry to reconstruct the decadal scale glacial history of an unmonitored Alpine valley glacier, the Haut Glacier d'Arolla, Switzerland, and we use the data generated to explore the linkages between glacier recession and climate forcing. High precision digital elevation models were derived. They show continual recession of the glacier since 1967, associated with long‐term climatic amelioration but only a weak reaction to shorter‐term climatic deterioration. Glacier surface velocity estimates obtained using surface particle tracking showed that, unlike for most Swiss glaciers during the late 1970s and early 1980s, ice mass flux from the accumulation zone was too low to compensate for the effects of glacier thinning and subsequent snout recession, especially during the rapid warming that occurred through the 1980s. The results emphasise the dangers of inferring glacier response to climate forcing from measurements of the terminus position only and the importance of using remote sensing methods as an alternative, especially where historical imagery is available.  相似文献   
414.
The mass balance of Urumqi Glacier No.1 (Glacier No.1) was calculated by water balance method and direct measurement method respectively. Water balance method is a kind of calculating method, which studies about the relationship between storage, supply and consumption of water resource in a certain area in a certain period of time (Time for this research is a mass balance year).Mass balance calculated by this method and acquired by filed observation was compared and analyzed. Therefore we got their correlation and expected to apply it to other high latitude and altitude areas.Mass balance and glacial runoff data of Urumqi Glacier No.1 used in this research were acquired from Annual Report of Tianshan Glacier Station, and that started observing in 1959.The data used by this study is collected from 1982-2014. The data of runoff was measured by the hydrology station of Urumqi Glacier No.1 Glacier, which is located in the lower reaches of the glacier about 300 m, and catchment area is about 3.34 km2.The data of precipitation and runoff was provided by Daxigou Meteorological Station located in the altitude of 3 539 m, which is distant from the terminus of Urumqi No.1 Glacier about 3 km.Through the comparison of these two kinds of methods, we found that: ①It is better to use water balance method to calculate the mass balance in long time series. The result of water balance method was 1% different from the result of direct measurement during 1982-2014, and the corresponding glacier runoff coefficients were 0.7 and 0.85, respectively. ②The results of water balance method during 1982-2005 had a high correlation with the direct measurements, and the error was relatively small. Besides that, the glacier runoff coefficient reflected the glacier runoff well. However, there were obvious differences between the two kinds of methods during 2005 2012 which showed that the glacier runoff coefficients changed a lot. According to analyzing the two periods of 2005 to 2008 with large error and 1996 to 1999 with small error, we found that the results of water balance method were generally higher than that of the direct measurement in summer. The analysis showed that the changes of water conditions and the corresponding in the glacier runoff coefficient were the main reasons for these differences.The data of precipitation and runoff in the study area was combined with the measured mass balance data, and their potentially internal relationship was found, which could be used to acquire the meteorological data easily and to deduce the mass balance data which is difficult to be acquired. This conclusion is helpful to extending the study area from a single glacier or basin to a large regional scale. Limited to the shortage of data, for the example, this study only discusses the single glacier, Urumqi Glacier No.1. Overall, this study shows that using the potential of water balance method can compute the data of glacier mass balance more accurate on long time scale.  相似文献   
415.
IPCC SROCC和AR6对高山区气候变化的评估表明,近期全球山地增暖速率提高,1980年代以来亚洲高山区增暖速率明显高于全球平均和其他高山区同期水平。各山地增暖普遍具有海拔依赖性,但机制复杂且区域差异大,除落基山脉未来气温增幅随海拔降低外,其余山地均随海拔有不同程度的升高。全球山地年降水在过去几十年没有明显趋势;预计未来北半球许多山地年降水将增加5%~20%,但极端降水变化的区域和季节差异较大,其中青藏高原喜马拉雅山脉极端降水频次和强度都将增大。山地年最大雪水当量的减少在固-液态降水转化的海拔高度带更强,未来山地降雪和积雪变化不仅与排放情景有关,而且与海拔高度密切相关。2010—2019年全球山地冰川物质亏损较有观测记录以来的任何一个10年都多,亚洲高山区虽然冰川物质亏损速率较小,但每年亏损的冰量在全球四大高山区中仅次于安第斯山脉南段。预计山地冰川将持续退缩数十年或数百年,未来亚洲高山区冰川退缩对海平面上升的贡献将居全球四大高山区之首。山地多年冻土温度升高、厚度减薄,预计未来多年冻土将加速退化,即使在低温室气体排放情景下,21世纪末青藏高原多年冻土面积预计也将减少13.4%~27.7%。从评估的完整性和信度水平来看,山地观测和研究仍存在巨大差距。  相似文献   
416.
东昆仑山煤矿冰川雷达测厚及冰储量估算   总被引:4,自引:3,他引:1  
基于2015年5月东昆仑山煤矿冰川冰厚测量资料,结合2015年Landsat8 OLI影像,利用Ordinary Kriging插值方法对冰川非测厚区进行插值计算,绘制了该冰川厚度等值线并对该冰川冰储量进行了估算。2015年煤矿冰川最大厚度为87 m,位于海拔4 952 m主流线附近,平均厚度为25.77 m,冰储量为0.0242 km3。利用煤矿冰川冰面地形图与冰厚度分布图,获得该冰川冰床地形图。结果显示,冰川上宽下窄沿山谷分布,冰床地形复杂,在冰厚较大区域,地形呈近“V”字分布,显示了冰斗冰川的形貌特征。  相似文献   
417.
通过2013年6-9月对唐古拉山冬克玛底冰川流域河水的逐日定时样品采集,并结合流域水文与气象资料,对径流的总溶解固体(TDS)和悬移质的变化特征进行分析。结果表明:2013年消融期的平均气温为3.7℃,消融期降水量为546 mm,7月和8月两个月径流量占消融期总径流量的63%。消融期逐日的TDS变化范围为31~140 mg·L-1,平均值为60 mg·L-1,TDS随径流变化显著,表现为消融强烈时(7-8月) TDS浓度较低,消融初期(6月)和末期(9月)时TDS浓度较高;径流中TDS与悬移质浓度(SSC)变化表现出相反变化趋势,即消融强烈时悬移质浓度较高,而消融初期与末期悬移质浓度较低,消融期平均悬移质浓度为122.8 mg·L-1,流量-SSC时序关系表现为以顺时针滞后事件为主。2013年冬克玛底冰川流域消融期的化学侵蚀总量和物理侵蚀总量分别为2.214×103 t和6.722×103 t,化学侵蚀与物理侵蚀率的比值为0.33。  相似文献   
418.
跃动冰川的监测相对比较困难。本文采用Sentinel-1所携带的C波段合成孔径雷达特征匹配方法(Feature-Tracking)获得了喀喇昆仑北坡克勒青河谷音苏盖提冰川物质平衡年内比较详细的冰川表面流速。分析发现:选取的音苏盖提三条分支冰川中,南斯嘎姆里冰川(Skamri Glacier)流速整体大于其余两条,三条分支均存在快速运动区,斯嘎姆里冰川和北分支积累区流速突增,可能存在雪崩现象;两条南分支冰川整体流速夏季大于其他季节,而北分支冬季流速大于其他季节。虽然三条分支均存在快速运动区域,但是即使是流速最快的南斯嘎姆里冰川在物质平衡年内的运动速度也只有119 m·a-1,说明该物质平衡年内音苏盖提冰川并不处于跃动期。  相似文献   
419.
自20世纪90年代以来,受全球气候变暖的影响,中国冰川呈现全面、加速退缩的趋势。冰川变化引发的水资源时空分布和水循环过程的变化无疑将给中国西部,尤其是西北干旱区的社会经济发展带来深刻影响。为了减缓冰川消融速率,提高中国适应气候变暖的能力,开展了一系列人工减缓冰川消融试验研究。具体是在2020年8月5日—10月17日,以达古17号冰川为研究标靶,进行人工干预减缓冰川消融试验,即在冰川表面覆盖光热阻隔物——土工织物,并在试验期间,观测了试验区域与非试验区域的冰川消融情况。结果表明:试验期内,试验区的冰川消融速率为0.011 m w.e.?d-1,非试验区冰川消融速率为0.017 m w.e.?d-1,试验区冰川消融速率明显低于非试验区;500 m2的土工织物使达古冰川试验区域减少了204 m3 w.e.的冰川消融,使得总消融量减少了34%;覆盖光热阻隔物虽能有效减缓冰川消融过程,但受成本、环境及人力等因素制约,仅可以向西北部小冰川或冰川旅游景点推广。本次人工干预减缓冰川消融试验在一定程度上填补了中国应对冰川消融工程措施方面的空白,为以后进行工程类减缓冰川消融的试验奠定了基础,但是目前还处于初步研究阶段,需要更多的控制性试验来验证其在未来更大的时空尺度上的有效性。  相似文献   
420.
基于多源数据的天山乌鲁木齐河源1号冰川变化研究   总被引:1,自引:1,他引:0  
基于2012年RTK-GPS、2015年三维激光扫描和2018年无人机航测数据,以天山乌鲁木齐河源1号冰川为研究区,分别从物质平衡、面积、末端等方面分析近期冰川变化。结果表明:乌鲁木齐河源1号冰川近年来呈快速消融趋势。2012—2018年冰川面积减少0.07 km2,年平均面积变化率为-0.01 km2·a-1;同期,冰川末端退缩率为6.28 m·a-1,且2015—2018年退缩速率大于2012—2015年;2012—2018年间表面高程下降,物质平衡为-1.13±0.18 m w.e.·a-1,物质损失主要发生在消融区。将2012—2018年间大地测量法冰川物质平衡与传统的花杆/雪坑法观测结果相比较,发现二者较为一致。而2012—2018年间物质平衡减小速率(-0.64 m w.e.·a-1)大于1980—2012年间(-0.47 m w.e.·a-1),表明近期乌鲁木齐河源1号冰川继续呈快速消融趋势。  相似文献   
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