Volcano Aviation Codes and Alert Levels in English and Samoan
Notifications about the status of activity at U.S. volcanoes are issued through the five regional U.S. Volcano Observatories. Additional information on the alert-notification system can be found in the Fact Sheet U.S. Geological Survey's Alert-Notification System for Volcanic Activity.
The USGS alert-level system for volcanic activity has two parts – 1) ranked terms to inform people on the ground about a volcano's status and 2) ranked colors to inform the aviation sector about airborne ash hazards. This document contains information on Aviation Color Codes and Volcano Alert Levels in English and Samoan.