The processes and characteristics of mass balance on the Urumqi Glacier No. 1 during 1958–2009     

WenBin Wang  ZhongQin Li  GuoFei Zhang  XuLiang Li 《寒旱区科学》2012,4(6):0505-0513

As a solid reservoir, a glacier can regulate regional water resources. The annual net mass balance directly reflects the fluctuation of the glacier and climate variability. Based on 51 years of mass balance observation data, the mass balance of Tianshan Mountains Urumqi Glacier No. 1 experienced a nine times positive balance fluctuation and nine times negative balance fluctuation. There were 35 and 16 negative and positive balance years, respectively. From 1996/97 to 2008/09, 12 consecutive negative balance years were observed at Tianshan Mountains Urumqi Glacier No. 1. These results demonstrate that the Urumqi Glacier No. 1 is experiencing a strong negative balance, and the strongest negative balance, -931 mm w.e. (mm water equivalent), during the observation period occurred in 2008. In addition, the cumulative mass balance reached 13,709 mm w.e. in 2008. However, in 2009, the mass balance was positive at 63 mm w.e. The equilibrium-line altitude changes with the fluctuation in the mass balance, and the effective mass balance gradient is 7.4 mm/m. In this paper, the headwaters of the Urumqi River were analyzed using meteorological data from 1958 to 2009, including the average seasonal temperature and precipitation. The results showed that the main factor associated with the mass balance variation of Glacier No. 1 is the fluctuation in the summer air temperature, followed by changes in the precipitation.  相似文献   

基于Sentinel-1的典型地物时间失相干分析     

佀文娜  何敏  王茂山 《地理空间信息》2022,20(2):22-26,32

为了探究影响Sentinel-1时间失相干的因素,实验选取美国南加州柯汶纳市及其周边区域进行研究,使用50景Senti-nel-1数据,分析了不同地物的时间失相干现象,并研究了风雨等天气因素及不同极化方式对相干性的影响.主要得出以下结论:Sentinel-1数据典型地物的失相干特征区别较大,可以较好地指导地物识别、辅助...  相似文献   

武山1号泉流量、O_2+Ar、N_2、He的异常变化分析          下载免费PDF全文

杨兴悦  王益  王燕  廖祯祥  李树全  朱振家 《地震工程学报》2008,30(1):75-78

对武山台1号泉气体资料显示,在1997-1999、2003年流量有几次明显的突变,同时气体组分O2 Ar、N2、He百分含量与流量呈完全同步变化.本文分析了造成流量突变的原因,认为流量大幅度变化不是自然动态的.同时用试验方法验证了影响气体组分O2 Ar、N2、He百分含量变化的主要因素是流量、冲流时间和空气混入了泉水,并分析了它们之间的相互关系及变化特点.  相似文献   

设定地震及其烈度影响判别   总被引：1，自引：0，他引：1  

聂树明  周克森 《华南地震》2008,28(2):47-52

设定地震常用于震害预测、地震小区划和重大工程选址,烈度衰减模型反映了地震引起的地面震动及其影响的强弱程度分布。设定地震包括确定性和非确定性设定两种方法,确定性方法基于构造或历史地震,非确定性方法是基于概率危险性方法,用于估计区域或城市未来可能遭遇的地震危险。缺失等震线或震害记载不详的历史地震和概率设定地震都不能确切地反映地震破坏影响,借助于烈度衰减关系模型和GIS,可直观地判别其影响分布情况,便于设定地震的取舍。  相似文献   

A layered model of the upper crust in the Aigion region of Greece,inferred from arrival times of the 2001 earthquake sequence     

O.?NovotnyEmail author  J.?Jansky  V.?Plicka  H.?Lyon-Caen 《Studia Geophysica et Geodaetica》2008,52(1):123-131

The western part of the Gulf of Corinth attracts attention due to its seismically active fault system and considerable seismic hazard. Detailed studies of the seismic activity of the region have been carried out especially as part of the so-called Corinth Rift Laboratory (CRL) Project. For standard earthquake locations, the CRL uses the HYPO algorithm and a special structural model that is composed of homogeneous layers (Rigo et al., 1996). This model was derived from a passive seismic experiment in a broader area around the western part of the Gulf. A significant part of the seismic activity is concentrated close to the town of Aigion, which was damaged by a strong earthquake in 1995. A sequence of smaller earthquakes occurred to the south of this town in the year 2001. In the present paper, we have used this sequence to derive an improved structural model for the region in the vicinity of the town of Aigion. This new model is based on the minimization of travel-time residuals. In particular, we used arrival times from a subset of 88 events recorded by at least 5 stations of the southern part of the CRL network, had magnitudes of over 2.3, and were recorded at the nearest station (station code AIO). A variant of the method of conjugate gradients has been used for this purpose. In comparison with the model derived by Rigo et al. (1996), the new model is characterized by a higher ν_P/ν_S velocity ratio and by higher velocities to a depth of about 7 km. The new model was derived with the aim to get more accurate locations of future events in the vicinity of the town of Aigion.  相似文献   

FHD-1矢量质子磁力仪与温度相关性分析     

陈传华  邢伟伟  林秀娜 《华北地震科学》2008,26(1):30-34

通过矢量质子磁力仪FHD-1各分量北京时21点数据、日均值数据和室内记录的温度值作相关性分析,探讨温度对线圈和产出的数据是否有影响。  相似文献   

GM3磁通门磁力仪稳定性分析   总被引：1，自引：1，他引：0  

尚先旗  张明东  胡培元 《地震地磁观测与研究》2008,29(6):144-148

通过2002～2003年的GM3磁通门磁力仪的资料,对该仪器的各项指标进行稳定性分析,考核运行状态是否正常,以证明是否替代模拟观测仪器。  相似文献   

Comparison of two different solutions to Molodensky’s G1 term     

M. Vaľko  M. Mojzeš  J. Janák  J. Papčo 《Studia Geophysica et Geodaetica》2008,52(1):71-86

The main purpose of this paper is comparison of two different approaches of solution to the Simple Molodensky’s Problem, the Molodensky’s Approach and the Analytical Continuation Approach, based on numerical computation. Although these approaches have been described theoretically by several authors, e.g. Molodensky et al. (1960), Heiskanen and Moritz (1967), Vaníček (1974), Moritz (1980) and Holota (1991, unpublished results) and theoretical proof of equivalence was given by Heiskanen and Moritz (1967), Moritz (1971), Ecker (1971) and Pellinen (1972, unpublished results), only very few practical experiences about the differences between particular solutions and computational efficiency exist. In this paper we compare the above two mentioned approaches in terms of the G₁-effect on quasigeoid. Both quasigeoid solutions are tested by the independent GPS/levelling approach and are also compared with the previous quasigeoid model of Slovakia where the G₁-term has been approximated using the classical terrain correction. The effect of the G₂-term is also numerically estimated, revealing that it might be significant for the precise quasigeoid determination. Some practical comments and recommendations are given at the end of the paper.  相似文献   

Flood‐based analysis of high‐magnitude sediment transport using a non‐parametric method     

T. Francke  J. A. López‐Tarazón  D. Vericat  A. Bronstert  R. J. Batalla 《地球表面变化过程与地形》2008,33(13):2064-2077

Upland erosion and the resulting reservoir siltation is a serious issue in the Isábena catchment (445 km² Central Spanish Pyrenees). During a three‐month period, water and sediment fluxes have been monitored at the catchment outlet (Capella), two adjacent subcatchments (Villacarli, 41 km²; Cabecera, 145 km²) and the elementary badland catchment Torrelaribera (8 ha). This paper presents the results of the monitoring, a method for the calculation of a sedigraph from intermittent measurements and the derived sediment yields at the monitored locations. The observed suspended sediment concentrations (SSCs) demonstrate the role of badlands as sediment sources: SSCs of up to 280 g l^?1 were encountered for Villacarli, which includes large badland areas. SSCs at the Cabecera catchment, with great areas of woodland, barely exceeded 30 g l^?1. SSCs directly at the sediment source (Torrelaribera) were comparable to those at Villacarli, suggesting a close connection within this subcatchment. At Capella, SSCs of up to 99 g l^?1 were observed. For all sites, SSC displayed only a loose correlation with discharge, inhibiting the application of a simple sediment rating curve. Instead, ancillary variables acting as driving forces or proxies for the processes (rainfall energy, cumulative discharge, rising/falling limb data) were included in a quantile regression forest model to explain the variability in SSC. The variables with most predictive power vary between the sites, suggesting the predominance of different processes. The subsequent flood‐based calculation of sediment yields attests high specific sediment yields for Torrelaribera and Villacarli (6277 and 1971 t km^?2) and medium to high yields for Cabecera and Capella (139 and 410 t km^?2) during the observation period. In all catchments, most of the sediment was exported during intense storms of late summer. Later flood events yield successively less sediment. Relating upland sediment production to yield at the outlet suggests considerable effects of sediment storage within the river channel. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

青海省苦海汞矿床形成条件及成因探讨     

丁正江  孙丰月  李碧乐  赵俊伟  李世金 《吉林大学学报(地球科学版)》2009,39(1):9

苦海汞矿床是位于东昆仑造山带南带东段上的大型含金汞矿床。围岩为一套滨海-浅海相富含碳质碳酸盐（石英砂岩）建造。矿体受地层和构造联合控制,一般产在褶皱的层间剥离裂隙、构造裂隙及节理中,或产于褶皱翼部的断裂破碎带内。矿床成矿流体以建造水和大气降水为主,并可能有岩浆热液的加入。成矿流体盐度（w(NaCl)）为1.90%～5.70%,密度为0.78～0.97 g/cm³;流体包裹体均一温度为118.8～291.6 ℃;成矿压力约43.24 MPa,成矿深度为4.56 km。研究表明,该区下二叠统含碳地层提供了主要的成矿物质,晚三叠世受构造造山作用及相应的岩浆侵入所驱动的热液流体活化了矿质,并迁移至褶皱带层间剥离裂隙等部位沉淀成矿。总体上,该矿床为一受构造和地层联合控制的中偏低温热液矿床,相当于造山型金矿系列的浅成矿床。  相似文献