Reefs can be effective at curbing an impact of tsunamis.Logical formLearned from2 sentences. Earthquakes may be caused by volcanic activity.Logical formLearned from2 sentences. A volcanic eruption may kill some persons.Logical formLearned from2 sentences. A volcanic tremor can be shallow.Logical formLearned from2 sentences. Diversity can be in volcanic rocks.Logical formLearned from2 sentences. A danger may arise from volcanic eruption.Logical formLearned from2 sentences. A Spanish colony may be located between volcanic islands.Logical formLearned from2 sentences. A volcanic activity can be abnormal.Logical formLearned from2 sentences. A (winter resort) can be for volcanic craters.Logical formLearned from2 sentences. Volcanic activity may reduce.Logical formLearned from2 sentences. Volcanic activity may begin in an area.Logical formLearned from2 sentences. Volcanic eruptions may be preceded by seismic activity.Logical formLearned from2 sentences. Some volcanic tremors can be in some durations.Logical formLearned from2 sentences. Volcanic tremors can be high.Logical formLearned from2 sentences. A bulletin may report some volcanic tremors.Logical formLearned from2 sentences.