Volcanic activity refers to any kind of eruption, explosion or other change that occurs within a volcano. This can include anything from small steam emissions and gas release to full-blown eruptions of lava, ash and rock. Volcanic activity is often unpredictable and can vary in intensity, with some eruptions being relatively mild while others can be catastrophic, causing widespread damage and loss of life. The study of volcanic activity is an important part of understanding the Earth's geology and natural processes, as well as predicting and mitigating the risks associated with living near active volcanoes.