极地研究

极地研究 ›› 2014, Vol. 26 ›› Issue (2): 177-185.DOI: 10.13679/j.jdyj.2014.2.177

• 研究论文 •    下一篇

南极中山站-昆仑站间地壳厚度分布

冯梅1 安美建1 安春雷2 史贵涛2 赵越1 李院生2 Douglas Wiens3   

  1. 1中国地质科学院地质力学研究所，北京 100081; 2中国极地研究中心，上海 200136; 3Department of Earth and Planetary Science, Washington University, St. Louis, MO 63130-4899, USA
  • 收稿日期:2013-07-15 修回日期:2013-10-14 出版日期:2014-06-30 发布日期:2014-06-30
  • 通讯作者: 冯梅
  • 基金资助:

    国家自然科学基金“行星冲击产生的高温高压相变反应：月球火星陨石中后成合晶的研究”;科技支撑项目

CRUSTAL THICKNESSES ALONG THE TRAVERSE FROM ZHONGSHAN TO DOME A IN EAST ANTARCTICA

Feng Mei1，An Meijian1，An Chunlei2，Shi Guitao2，Zhao Yue1，Li Yuansheng2，Douglas Wiens3   

  1. 1 Institute of Geomechanics, Chinese Academy of Geological Sciences, Beijing 100081, China; 2 Polar Research Institute of China, Shanghai 200136, China; 3Department of Earth and Planetary Science, Washington University, St. Louis, MO 63130-4899, USA
  • Received:2013-07-15 Revised:2013-10-14 Online:2014-06-30 Published:2014-06-30
  • Contact: Mei Feng

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摘要： 自第四个国际极地年2007/2008开始至2013年，中国南极内陆冰盖科考队相继在自南极大陆边缘的中山站至东南极地形最高点昆仑站(Dome A)一线进行了低温甚宽频地震观测。这里对7个天然地震台数据进行了分析，提取了这些台站的S波接收函数，据此反演获得了这些台站下的地壳厚度分布。随着纬度的升高，地壳厚度由大陆边缘的中山站下的约38 km逐渐增加至CHNB台下的58 km，随后又于CHNA台站下方减薄至47 km，然后又快速增大到南极地形最高点昆仑站(Dome A)下的62 km。从中山站至昆仑站之间地壳厚度的变化与冰下地貌变化存在明显的相关性。这个变化说明了从昆仑站至CHNB之间构造相对均匀。昆仑站不但是南极大陆地壳最厚的地方，也可能是全球各克拉通中地壳最厚的地方。在距昆仑站约200 km的CHNA台下的地壳厚度(约47km)明显比临近台站地壳明显偏薄，这可能说明了甘伯采夫山脉地壳侧向变化较大，即其形成时的所遭受的构造作用较复杂。

关键词: 地壳厚度, 接收函数, 昆仑站, 东南极, 南极内陆科考

Abstract: From the 4th International Polar Year in 2007/2008 to 2013, Chinese Antarctic inland icecap expeditions deployed cold-mode very-broadband seismic stations along the path from Zhongshan to Kunlun (Dome A). Using the observations recorded by the stations, we retrieved S-receiver functions of 7 stations from seismic waveform observations, and inverted for crustal thicknesses beneath the seismic stations using the receiver functions. The result shows, with the increasing of latitude of the seismic stations, crustal thicknesses increase from 38 km beneath Zhongshan station to ~58 km beneath EAGLE and CHNB; then decrease to 47 km beneath CHNA; and finally increase to 62 km beneath the highest point of the Antarctica, Kunlun station (Dome A). This thickness variation is consistent with the bedrock surface variation along the path. The thickness variation indicates that the tectonics between Zhongshan and CHNB is relatively homogeneous. The crustal thickness beneath Kunlun station is not only the largest in Antarctica but also is very large comparing with cratons in other continents. The crust beneath CHNA is ~10 km thinner than neighboring stations, which may be resulted by short-time observation for the station and also may indicate that the crustal structure lateral variation is very large.

Key words: crustal thickness, seismic station, Dome A, East Antarctica, Antarctic expedition