中国大陆1998～1999年地壳运动观测结果

CRUSTAL MOVEMENT IN CHINA MAINLAND OBSERVED FROM 1998 TO 1999

介绍了中国地壳运动观测网络 1 998～ 1 999年基准站 GPS观测概况 ,简要介绍了用伯尔尼 (Bernese)软件对 GPS观测数据的处理结果 ,详细介绍了所获取的 1 998年 9月初～ 1 999年 7月初基准网地壳运动 ,包括各基准站位移与网内各部分的应变 .在所述观测期间 ,我国东部地区较为稳定 .相对东部地区 ,西南部地区以向北运动为主 ,位移量约 1 7mm,受北北东向挤压为主 ;西北部地区以北西向运动为主 ,位移量约 1 1 mm;而云南地区以向南运动为主 ,位移量约 1 4 mm.我国中部南北地震带则是一强烈的剪切变形带 .网内最大主应变量为2 .9× 1 0 -8.观测结果表明 ,印度板块向北挤压依然是影响我国地壳运动的主要因素 .

WT5BZ]In this paper, GPS observations during 1998 to 1999 at fiducial stations in the Crustal Movement Observation Network of China (CMONOC) and GPS observation data processing with Bernese Software are briefly introduced. The processed results of crustal movement in the network during the period from early September 1998 to early July 1999, including the displacements at each fiducial station and strains in different part of the network, discussed in detail. During the above mentioned period of observations, the eastern part of China was relatively stable. In contrast with it, the southwest part of China moved northwards about 17 mm with a dominant compression in NNE; the northwestern part of China moved northwestwards about 11 mm; and the Yunnan area moved southwards about 14 mm. The North South seismic belt in the middle part of China is a belt of strong shear deformation. The maximum principal strain in the network is 2.9×10 -8 . The observation result shows that the northward push by the Indian plate has still played the dominant role in the crustal movement in China.