台湾中部造山带前缘强震发生的构造环境分析(英文)

SEISMOTECTONIC CHARACTERISTICS IN THE FRONTAL OROGENY OF CENTRAL TAIWAN

台湾中部造山带前缘呈现为一弧形逆冲构造体系。每个弧形带分别由不同尺度但各自独立的次级弧形构造所组成。而每一个弧形构造都有其各自独立的几何、运动和动力学特征 ,是典型的板块造山运动变形带前缘之褶皱逆冲带 ,但同时各个次级弧形构造间却又有自相似特性。台湾中部弧形系列构造带 ,由运动学看来 ,是从弧形顶部向西逆冲向两侧过渡到斜冲 ,到弧凹处的逆冲为止。每一个地震活动带与独立活动的弧形逆冲构造间可能有一定的对应关系存在。大地震发生在规模较大的弧形构造上 ,而中小地震则发生在规模较小的次级弧形构造上。在对台湾中部地区弧形逆冲体系的空间位置与地震活动间关系研究的基础上 ,文中归纳出中部弧型逆冲地震带的地震活动特征。

The orogeny of central Taiwan shows an arcuate thrust tectonic system. Every arcuate belt is composed of a series of different scales of sub-arcs. Each arcuate structure is a typical fold-and-thrust belt and presents its own independent characteristics of geometry, orogenic movement, and tectonic mechanics. On the contrary, a self-similarity exists in the sub-arcs. According to the orogenic movement, the arcuate structures thrust towards the west from the top to the bottom of arcs with obliquely pushing and wrenching. Each deformation belt of earthquake is related to the independent thrust arc. Strong earthquakes correspond to the large-scale arcs, and medium earthquakes correspond to the small ones. Analysis is carried out on the relation between the contemporary seismicity and the arcuate thrust structures in central Taiwan, especially on Chi-Chi aftershock series.