At least 100 active volcanoes occur along the North Pacific convergent plate margins stretching from south-central Alaska and the Aleutians to the Kamchatka Peninsula and the Kuriles. Although sparsely populated, the North Pacific is one of the world’s busiest air traffic corridors. An average of 200 flights, 20,000 passengers and 12,000,000 pounds of air cargo travel daily over or immediately downwind of these volcanoes. Annual growth rate estimates for air traffic between Asia and North America and Europe range from 5 – 20%. Meanwhile, long term eruption records suggest that volcanic ash from one of these volcanoes will reach altitudes that could endanger jet aircraft on an average of 4-5 days per year.

To address this significant risk, international, federal, and state organizations and private industry work together to issue effective volcanic hazard warnings. Earth science agencies with primary responsibility for detecting and issuing warnings of volcanic unrest in the North Pacific are the closely-linked Alaska Volcano Observatory (AVO) and the Kamchatka Volcanic Eruption Response Team (KVERT). Both utilize real-time seismic networks, satellite remote sensing of ash and thermal anomalies, and visual observations to detect volcanic activity. Warnings are issued by phone, fax, and internet to an established recipient list. Information is also rapidly posted on a public web page. AVO works closely with the National Weather Service and the Federal Aviation Administration to ensure that formal operational guidance to the aviation community contains all pertinent volcanic hazard information. During non-crisis times, AVO and KVERT issue weekly status reports on all seismically monitored volcanoes and conduct geological studies in support of hazard assessments. Agency responsibilities, relationships, and operational protocols for eruptions in Alaska are formalized in the “Alaska Interagency Plan for Volcanic Ash Episodes”. Frequent review of response protocols is required to maintain proficiency and to meet increasing demands for rapid volcano hazard communication.