< p >的原因是部分几何和部分的过程。俯冲带一般采取海洋地壳和上地幔到更深的地幔,但俯冲带的角度千差万别。例如,汤加海沟非常陡峭,引起一个“紧”地震灾区。最浅的,这两个板块边界甚至不是一个俯冲带,但变得仰冲,掩冲板海洋地壳和地幔,发生在阿曼蛇绿岩。还有ocean-continent碰撞,如西部南部美洲。因为大陆地壳比海洋地壳密度较低,更活跃,所以你会得到一个更广泛的俯冲带比你会背弧覆盖洋洋碰撞。最后,还有continent-continent碰撞,典型India-Tibet,那里没有一个地壳下沉非常深,所以得到一堆迭瓦over-thrusts,西藏大部分地区和喜马拉雅山,所有有关地震在数百公里宽,如去年的尼泊尔地震。< / p > < p >还要考虑所涉及的构造。即两个构造板块相互滑动可能有很少或没有俯冲,但横推断层应力释放仍然可以创建大地震——认为圣安德烈亚斯断层,或者是新西兰人。Kim指出地震区域的厚度如澳大利亚北部。 It isn't just in southeast Asia. We can see similar complexities in the Eastern Mediterranean, the Caribbean and elsewhere, where there are many micro-plates jostling in a complex pattern. They only seem like one seismic zone because of the scale of your diagram. There is yet a different story in the Rift Valley of Africa. The above are just some sketchy simplifications of a revolution in geological understanding that started in the late 1960s, and which are still continuing. It's not possible to give a detailed explanation in this forum, but there are many excellent and fascinating textbooks. Warning - you can get hooked. Then it becomes a lifetime study.