Japan meteorological agency official masahiro yamamoto is warning of powerful aftershocks . mr . yamamoto says tremors of magnitude 6 are possible . there is concern that further aftershocks could also trigger landslides 日本气象厅地震海啸监视科长山本雅博警告说，接下来可能还会发生强烈余震。山本雅博说，还可能会发生六级地震，而且他们担心再发生余震的话，可能会导致滑坡。
