火山是地下深处的高温岩浆及其有关的气体、碎屑从地壳中喷出而形成的特殊地质体。火山活动常以地震或气体逸出作为先兆。喷发时有的产生爆炸，大量气体和尘埃从火山口中喷出混合形成高耸入云的“烟柱”；；人们把周期性喷发的火山称为活火山，历史无记载且火山构造已遭严重破 Volcanoes are special geologic bodies formed by the exothermic magma and its associated gases in the depths of the underground where debris is ejected from the earth’s crust. Volcanic activity is often a precursor to earthquakes or gas escaping. Eruptions sometimes explode, leaving large quantities of gas and dust emanating from the crater to create towering “smoke pillars.” People call volcanic eruptions periodically active volcanoes, with no record of history and volcanic structures that have been severely damaged