Ashfall refers to the deposition of volcanic ash that occurs during an eruption. This ash consists of tiny fragments of rock, minerals, and volcanic glass that are ejected into the atmosphere. When the ash settles back to the ground, it can cover large areas, affecting the environment and human activities. The impact of ashfall can be significant, leading to reduced air quality and visibility. It can also damage crops, contaminate water supplies, and disrupt transportation. Areas near active volcanoes, such as Mount St. Helens or Kilauea, are particularly vulnerable to ashfall events.