ICAO Doc 9691:2015

The main purpose of this manual is to assist States and international organizations involved in the international airways volcano watch (IAVW) by providing guidance on the scientific aspects of volcanic eruptions and volcanic ash in the atmosphere (including volcanic ash cloud observation/detection and movement) and the effects of volcanic ash on aircraft operations, and by providing guidance regarding States’ responsibilities within the IAVW. The manual also provides information concerning the requirements for the provision of warnings to aircraft of radioactive materials and toxic chemical clouds and guidance regarding how these requirements may be satisfied.