Additional sedimentation occurred until a subduction zone formed off the coast .
直至一個(gè)潛沒帶在距離海岸處形成前,額外的沉積作用一直存在。
How do earthquakes arise in undersea subduction zones , which account for 90 per cent of all seismic energy released worldwide ?
占全球地震能量釋放90%的地震是怎樣發(fā)生于海底俯沖區(qū)的?
The cascadia subduction zone , just 50 miles off the coast and stretching from northern california to southern british columbia , is accumulating stresses that could unleash an earthquake of magnitude 9.0 and generate its own tsunami .