Volcanic-ash hazards are far reaching and disruptive, affecting more people, infrastructure, and daily activities than any other eruptive phenomena.

This web encyclopedia provides information on the impacts of volcanic ash and mitigation strategies for dealing with them. Content is summarized from expert and peer-reviewed sources.

• Use 'Choose Topic' in the header or the left menu to find information categorized by affected sector.
• Posters and booklets in a range of languages are available in Resources.
• Technical guidance for scientists undertaking ash studies is presented in the For Scientists section.
• Do you have technical information or images you'd like to contribute to this Web site? New case studies and well documented experiences are valuable, and we welcome your contributions. Please Contact Us if you have information to add or questions.