Greenland Ice Sheet surface melt: A review     

Kang Yang  ManChun Li 《寒旱区科学》2014,6(2):0099-0106

Surface melt has great impacts on the Greenland Ice Sheet （GrlS） mass balance and thereby has become the focus of significant GrlS research in recent years. The production, transport, and release processes of surface meltwater are the keys to understanding the poten- tial impacts of the GrlS surface melt. These hydrological processes can elucidate the following scientific questions： How much melt- water is produced atop the GrlS？ What are the characteristics of the meltwater-formed supraglacial hydrological system？ How does the meltwater influence the GrlS motion？ The GrlS supraglacial hydrology has a number of key roles and yet continues to be poorly understood or documented. This paper summarizes the current understanding of the GrlS surface melt, emphasizing the three essential supraglacial hydrological processes： （1） meltwater production： surface melt modeling is an important approach to acquire surface melt information, and areas, depths, and volumes of supraglacial lakes extracted from remotely sensed imagery can also provide surface melt information; （2） meltwater transport： the spatial distributions of supraglacial lakes, supraglacial sarams, moulins, and crevasses demonstrate the characteristics of the supraglacial hydrological system, revealing the meltwater transport process; and （3） meltwater release： the release of meltwater into the englacial and the subglacial ice sheet has important but undetermined impacts on the GrlS motion. The correlation between surface runoff and the GrlS motion speed is employed to understand these influences.  相似文献   

Taimyr Peninsula( Arctic Siberia) in Late Precambrian:tectonic thrust sheets and geodynamic evolution     

Sergey G.Samygin 《东北亚地学研究》2014,(3)

Structural relationships between the Neoproterozoic rock complexes of a continental massif,island arc and back-arc basin geodynamic affinities are described and considered in this work based on field observations within the northeastern segment of the Central Taimyr tectonic zone distinguished in the late Hercynian foldthrust belt of Taimyr Peninsula. As is established for the first time,rock complexes of the continental massif with the early Late Riphean( Tonian-Cryogenian) volcanogenic-sedimentary cover occur in the study region as the allochthonous syn- and post-sedimentary thrust sheets buried in or thrust over deposits of a back-arc basin,which accumulated in the terminal Late Riphean( Cryogenian)--initial Vendian( Ediacaran). These and other results of the large-scale structural observations elucidate important details of the region tectonic development in the Late Precambrian,when two lateral ensembles of the Neoproterozoic structures originated in the region. In the first half of the Neoproterozoic,the regional tectonic ensemble included the oceanic plate abut on the continental massif with a primitive volcano-plutonic belt. The subsequent system of an island arc and marginal backarc basin originated in the second half of the Neoproterozoic and existed approximately till the mid-Vendian( Ediacaran) phase of the intense formation of thrust sheets in the region.  相似文献   

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������  Ԭ����  ��Ԫ��  ��ʤ��  л����  ��  ��  ���¹� 《大地测量与地球动力学》2014,34(6):41-43

????2004??2008???ICESat???????????????GLA12???????????????????????????????????????仯????????????????????????????????????仯??????????????????????????????3 m??????????????????????仯?????????????????????????????????  相似文献   

南海琼东南盆地深水区储层类型及研究意义   总被引：1，自引：1，他引：0       下载免费PDF全文

王艳 《沉积与特提斯地质》2014,34(3):82-87

通过对琼东南盆地钻井及典型地震相分析,认为琼东南盆地深水区发育两种类型的储层:第一类为形成于浅水环境的储层,包括扇三角洲砂体、滨浅海相滩坝砂体和台地碳酸盐岩;第二类为形成于深水环境的储层,包括盆底扇和峡谷水道等低位砂体。其中,深水区广泛分布的海底扇、峡谷水道砂体和台地碳酸盐岩具有良好的深水油气勘探潜力。  相似文献   

东濮凹陷构造演化对浅层油气成藏的影响          下载免费PDF全文

冯阵东  程秀申  付晓龙  虎新军  高斌  徐炳文 《沉积与特提斯地质》2014,(1):8-13

通过计算地层的剥蚀厚度、断层断距,分析了古近纪以后两个最主要时期的构造运动特征,将构造演化与浅层油气藏地化指标、包裹体均一温度、同位素测年等结果相结合,分析了新构造运动对油气生成、运移路径、成藏期次及时间的控制作用。研究认为:东濮凹陷新构造运动主要发生在东营组、明化镇组沉积末,运动以垂直升降为主,伴有弱的伸展断裂;两次构造运动控制了烃源岩的二次生烃和浅层油藏的二次充注;深部生成的油气运移至浅层依次经过了NE向基底断裂、东营组砂体、新近系EW向断层,新近系油气分布主要受EW向断层控制。  相似文献   

梯级水库设计洪水最可能地区组成法计算通式   总被引：2，自引：0，他引：2       下载免费PDF全文

刘章君  郭生练  李天元  徐长江 《水科学进展》2014,25(4):575-584

利用Copula函数建立各分区洪水的联合分布,基于联合概率密度最大原则,推导得到最可能地区组成法的计算通式,并用来推求梯级水库下游断面的设计洪水。选择清江流域水布垭-隔河岩-高坝洲梯级水库为例,开展了验证和方法比较研究。结果表明:最可能地区组成法计算得到的设计洪水值位于同频率地区组成法多方案计算结果的区间之内;受清江梯级水库调洪的影响,宜都断面设计洪水的削峰率十分显著,最可能地区组成法推求100年一遇设计洪水的削峰率达到30.2%。该法具有较强的统计基础,组成方案唯一,结果合理可行,为复杂梯级水库设计洪水的计算提供了一种新途径。  相似文献   

典型黄土坡面土壤侵蚀特征及径流流速空间变化试验研究     

和继军  黎雪晴  蔡强国  孙莉英  王硕 《地理研究》2022,41(5):1327-1337

为了明确土壤性质对坡面侵蚀方式作用机制的影响,本研究采用室内模拟降雨试验,选取黄土高原典型暴雨强度,在不同坡度条件下,对两种黄土的坡面侵蚀方式、形态特征、产流产沙过程及其相应径流流速的变化规律进行了研究。结果表明,绥德土径流量明显高于安塞土,10º、15º和20º时前者的平均径流量分别比后者高出51.1%、55.5%和63.0%,且前者更易形成细沟,使得其平均含沙量和平均产沙率分别是后者的1.14~3.59倍和2.50~8.48倍。在片蚀阶段,与绥德土相比,安塞土的含沙量较高,后者的平均含沙量是前者的1.24~1.73倍,但两种土壤的含沙量和产沙规律相同,均表现为先快速增加到最大值,然后逐渐降低到相对稳定状态,该现象证明片蚀的初期阶段主要受控于径流输沙能力,后期受径流的剥蚀能力控制。在细沟侵蚀阶段,绥德土细沟发育以沟头溯源侵蚀为主,崩塌作用频繁,该侵蚀形式不仅控制着细沟形态的总体特征,也导致含沙量和产沙率均急剧增加,该阶段平均含沙量是相应片蚀阶段的3.25~4.34倍。细沟沟口下方坡面存在明显的泥沙沉积带,表明细沟集中水流的搬运能力远高于坡面漫流,细沟侵蚀主要受径流输沙能力控制。两种土壤的径流流速均表现为坡面下部高于坡面上部,径流稳定后高于径流稳定前,总体来看,绥德土和安塞土上坡和径流稳定后的平均流速分别是下坡和径流稳定前的1.4倍、1.25倍和1.75倍、1.29倍,此外细沟侵蚀或侵蚀强度与微地貌形态之间的互馈作用对径流流速也有较大影响。  相似文献   

HD-1注汽井新型防砂材料的研究与应用     

沈朝霞  梁富春  高成元  刁俊西  孙理达 《海洋地质译丛》2010,(3):61-63

孤岛油田属稠油疏松砂岩油藏,生产过程中油井出砂严重,现有的涂敷砂人工井壁防砂注蒸汽后强度较低,造成防砂成功率低,注汽后高强度采液生产周期较短。为此,通过室内试验,优选出耐高温树脂、高强度骨架颗粒、偶联剂、固化剂,进行室内配方优化试验,评价固结体耐高温性能,测定其渗透率,研制出一种适用于疏松砂岩油藏注蒸汽热采井的HD-1注汽井新型防砂材料。在孤岛油田稠油注蒸汽热采区共试验72口井,成功率为91.0%,截止目前,累计产油为121 572 t,单井平均有效期为233 d。现场应用表明：HD-1注汽井新型防砂材料耐高温、强度高,防砂成功率高,有效期长,能够有效改善注蒸汽热采井的防砂效果。  相似文献   

A 10Be production‐rate calibration for the Arctic     

NICOLÁs E. YOUNG  JOERG M. SCHAEFER  JASON P. BRINER  BRENT M. GOEHRING 《第四纪科学杂志》2013,28(5):515-526

  相似文献   

Abiotic Methane Reservoirs in the Western Tianshan HP–UHP Metamorphic Belt,China     

ZHANG Lijuan  ZHANG Lifei  LI Xiaowei  WANG Xiao 《《地质学报》英文版》2023,97(1):337-349

Natural gas, consisting primarily of methane(CH₄), has become a major source of clean energy in modern society in many parts of the globe. Recent experimental observations and discoveries of deep-sourced abiotic CH₄ in cold subduction zones indicate the important ability of cold subducted slabs to generate natural gas reservoirs. However, most CH₄ flux and reservoirs remain unknown and their potential is overlooked in global carbon flux estimations. Massive abiot...  相似文献