Global Volcanism Program | Image Collection | Hazards and Processes

Image Collection | Hazards and Processes | Ash Plumes and Ashfall

There are 5,971 volcano images available on the GVP website, including 4,243 in these new galleries with updated captions and keywords, and at a larger size.

Volcanic ash results from the explosive fragmention of magma and is composed of pieces of rock, glass, and crystal up to 2 mm in size. Volcanic ash and gas plumes rise above the vent to tens of meters to tens of kilometers in height. Large ash plumes can travel hundreds to thousands of kilometers away from the volcano, depositing ash on large areas. Volcanic ash is abrasive and heavy, resulting in damage to infrastructure and transportation. Ashfall can impact road safety, power supplies, water quality, equipment, technology and communications, wastewater disposal, and agriculture. Ashfall can have an impact on health depending on grain size, composition, and any preexisting conditions.

USGS Volcanic Ash Impacts and Mitigation website: https://volcanoes.usgs.gov/volcanic_ash/