VOLCANO SEISMICITY Volcano seismicity refers to the earthquakes and ground vibrations generated by volcanic activity. These quakes occur when magma rises through fractures, gas pressures build, or rock around a magma chamber breaks under stress. Unlike tectonic earthquakes, volcanic earthquakes are usually smaller in magnitude but are key warning signs of an impending eruption. By studying the patterns, depth, and frequency of volcanic tremors, scientists can forecast eruptions and protect nearb