| 基于远震接收函数的南极大陆冰盖厚度研究 |
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| 引用本文： | 晏鹏,李志伟,李斐,杨元德,郝卫峰,周磊.基于远震接收函数的南极大陆冰盖厚度研究[J].地球物理学报,2017,60(10):3780-3792. |
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| 作者姓名： | 晏鹏 李志伟 李斐 杨元德 郝卫峰 周磊 |
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| 作者单位： | 1. 武汉大学中国南极测绘研究中心, 武汉 430079;2. 中国科学院测量与地球物理研究所大地测量与地球动力学国家重点实验室, 武汉 430077;3. 武汉大学测绘遥感信息工程国家重点实验室, 武汉 430079 |
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| 基金项目： | 国家自然科学基金（41531069，41574004），南北极环境综合考察与评估专项（CHINARE2016-04-02，CHINARE2017-02-03，CHINARE2016-01-03），高校基本科研业务费专项资金（2014620020201，2015644020201）联合资助. |
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| 摘 要： | 冰盖厚度是研究南极冰盖质量、建立冰盖动力学模型的基本参数,对于冰川均衡调整、冰盖物质平衡及全球气候变化研究具有重要意义.基于地震学的远震接收函数和H-Kappa格网搜索方法可以用于地震台站下方冰盖厚度的可靠探测,不仅能与冰雷达获得的冰盖厚度进行独立对比,还可以与冰雷达方法相互补充,进一步填补南极大陆冰盖厚度探测空白区.本文利用布设于南极大陆冰盖上方的流动地震台阵记录到的远震波形数据,基于接收函数方法对台阵下方的冰盖厚度进行了研究.结果显示:基于远震接收函数方法的冰盖厚度与Bedmap2冰厚格网模型相比,二者差别大多在200 m以内;少数台站差值达到600 m左右,这一差别可能与Bedmap2测线分布空区、冰雷达测深不确定性以及冰盖内部复杂波速结构等因素有关.本文研究结果表明:利用南极大陆冰盖上方的流动地震台阵,基于远震接收函数方法可以获得比较可靠的南极冰盖厚度,为独立验证冰雷达的探测结果并弥补冰雷达探测空白区提供了有效方法.同时,部分台站接收函数波形的复杂性可能暗示了南极大陆数千米厚的冰盖内部结构不是均一的,仍然存在比较复杂的内部结构变化.因此,有必要进一步利用包括接收函数波形拟合、地震面波反演等方法对南极大陆冰盖厚度及其内部精细结构进行更为深入的研究.
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| 关 键 词： | 南极 冰盖厚度 远震接收函数 H-Kappa格网搜索 |
| 收稿时间： | 2016-09-20 |
Antarctic ice sheet thickness derived from teleseismic receiver functions |
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| YAN Peng,LI Zhi-Wei,LI Fei,YANG Yuan-De,HAO Wei-Feng,ZHOU Lei.Antarctic ice sheet thickness derived from teleseismic receiver functions[J].Chinese Journal of Geophysics,2017,60(10):3780-3792. |
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| Authors: | YAN Peng LI Zhi-Wei LI Fei YANG Yuan-De HAO Wei-Feng ZHOU Lei |
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| Institution: | 1. Chinese Antarctic Center of Surveying and Mapping, Wuhan University, Wuhan 430079, China;2. State Key Laboratory of Geodesy and Earth's Dynamics, Institute of Geodesy and Geophysics, Chinese Academy of Sciences, Wuhan 430077, China;3. State Key Laboratory of Information Engineering in Surveying, Mapping and Remote Sensing, Wuhan University, Wuhan 430079, China |
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| Abstract: | Ice sheet thickness is a fundamental parameter in research on Antarctic ice sheet mass and ice sheet dynamic model construction, which has great significance for glacial isostatic adjustment, ice sheet mass balance and global climate change studies. Accurate ice thickness acquired utilizing the seismological receiver function and H-Kappa grid search method can not only be an independent comparison and verification for the ice thickness obtained by radio echo sounding method, but also fill the gap of radio echo sounding measurement in Antarctica. In this paper, P-receiver functions (PRFs) are extracted from teleseismic events waveform data recorded by the temporary seismic arrays deployed on the ice sheet, then the ice thickness beneath the stations is calculated using the H-Kappa method. Compared the ice thickness derived from PRFs with Bedmap2 ice sheet thickness database, the results show that most of the differences are within 200 meters, and only a few reach 600 meters, which may be attributed to the vacancy of Bedmap2 survey lines and the uncertainty of radio echo sounding, as well as the inherit complexity of the inner ice structure beneath some stations. It can be concluded that the ice thickness obtained from the teleseismic receiver function method is reliable, thus it can not only be an independent verification for radio echo sounding results, but also provide an effective method for making up the limitations of radio echo sounding measurements. At the same time, the complexity of the receiver function waveforms beneath several stations may also indicate that the inner velocity structure of the Antarctic ice sheet is not homogeneous. There may be complex velocity structure in the ice sheet, and it is necessary to use some other methods such as receiver function waveform inversion and surface wave inversion for further study. |
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| Keywords: | Antarctica Ice sheet thickness Teleseismic receiver function H-Kappa grid search |
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