For the special surface conditions of land-water transition zone, the optimal excitation lithology, depth combined excitation have been researched, according to the near-surfacesurvey data.
针对水陆过渡带特殊地表条件，根据近地表调查资料，进行最佳激发岩性、井深和组合激发研究。
2
The Geological Survey initially said the quake had a depth of 142 miles (230km), but it later revised its estimate to say the quake was 6 miles (10 km) deep, putting it fairly close to the surface.