Compounds can be present in volcanic gases.Logical formLearned from2 sentences. A buildup can be volcanic.Logical formLearned from2 sentences. Volcanic activity may be expected in the future.Logical formLearned from2 sentences. A caldera can be a site of volcanic activity.Logical formLearned from2 sentences. Volcanic glass may be called obsidian.Logical formLearned from2 sentences. A caldera can be a focus of a volcanic activity.Logical formLearned from2 sentences. A focus may pertain-to a volcanic activity.Logical formLearned from2 sentences. Explosive eruptions may be driven by volcanic gases.Logical formLearned from2 sentences. A volume of volcanic rocks can be cubic kilometers.Logical formLearned from2 sentences. Explosions may be driven by volcanic gases.Logical formLearned from2 sentences. Volcanic gases may endanger life.Logical formLearned from2 sentences. Volcanic activity may pose a threat.Logical formLearned from2 sentences. Volcanic activity may continue after retreat of ice.Logical formLearned from2 sentences. Volcanic eruptions may undergo warnings.Logical formLearned from2 sentences. (Eruptions. ..s) can be volcanic.Logical formLearned from2 sentences.