Why doesn't GVP post alert levels?
The assignment of official volcanic hazard status designations, often called Alert Levels, is the responsibility of national or regional volcano observatories, civil defense agencies, or other designated government officials. Each country creates their own protocols for inter-agency responsibilities, communication, and collaboration. The following discussion is adapted from content provided by the World Organization of Volcano Observatories (WOVO), with permission.
In a volcanic crisis, there is often worldwide interest in the hazard status of that volcano. However, with the exception of color codes for aviation (see below), there is no standardized international volcano alert levels system. This is due to the wide variation in the behavior of individual volcanoes, differing monitoring capabilities, and the specific needs of populations, including different languages and symbolism of colors. Designing hazard status systems is not a trivial task, and proper execution requires the collaboration of specialists in many fields. National volcano observatories have developed hazard status protocols that may be regionally variable and differ significantly in detail. GVP provides links to the responsible national volcano observatories and the alert systems they utilize.
Organizations or individuals communicating about volcanic hazards or unrest are strongly cautioned against posting global alert levels or eruption "forecasts" that do not originate from official agencies with such responsibilities. Posting of alert levels can have major public safety and economic implications, and non-official levels published by those with only partial information and no interpretive experience can easily cause confusion. The data needed to provide alert levels comes from both onsite and remote monitoring instrumentation, and are best evaluated by observatory staff familiar with activity at their volcanoes. Any re-posting or publication of an official hazard status or alert level should include the date (and time if available) that the status became effective, the broad parameters of the system being used, the issuing agency, and a link (if appropriate) so that users can easily find the most current information. Hazard status can change quickly, and since GVP is not an operational agency, we do not provide an alert level dashboard or other compilation that is likely to be quickly out of date.
There is no WOVO-endorsed source of worldwide volcanic alert levels, with the exception of Aviation Color Codes. For those seeking a near real-time overview of current reported activity that incorporates direct observatory sources WOVO recommends the Weekly Volcanic Activity Report compiled by the Smithsonian Institution's Global Volcanism Program and the U.S. Geological Survey's Volcanic Hazards Program.
Many instances of aircraft flying into volcanic ash clouds have demonstrated the life-threatening and costly damages that can be sustained. Consequently, a global volcanic alert level system for aviation was developed as part of the International Airways Volcano Watch (coordinated by the International Civil Aviation Organization, a UN specialist agency), including the creation of nine regional Volcanic Ash Advisory Centers tasked with monitoring ash plumes within their assigned airspace. This system uses four color codes, designed to help pilots, dispatchers, and air-traffic controllers quickly find the status of numerous volcanoes that might endanger aircraft.
The color codes reflect conditions at or near a volcano and are not intended to indicate hazards posed downwind by drifting ash - all discernible ash clouds are assumed to be highly hazardous and to be avoided. The aviation color code should not be extrapolated to represent hazards posed on the ground, which might be quite different. Local observatories may have a completely different system to describe ground hazards independent of the ACC. The color codes are defined as below.
|Aviation Color Code||Definition|
|GREEN||Volcano is in normal, non-eruptive state. Or, after a change from a higher level: Volcanic activity considered to have ceased, and volcano reverted to its normal, non-eruptive state.|
|YELLOW||Volcano is experiencing signs of elevated unrest above known background levels. Or, after a change from higher level: Volcanic activity has decreased significantly but continues to be closely monitored for possible renewed increase.|
|ORANGE||Volcano is exhibiting heightened unrest with increased likelihood of eruption. Or, volcanic eruption is underway with no or minor ash emission. [specify ash-plume height if possible]|
|RED||Eruption is forecast to be imminent with significant emission of ash into the atmosphere likely. Or, eruption is underway with significant emission of ash into the atmosphere. [specify ash-plume height if possible]|
Global Volcanism Program, 2023. [Database] Volcanoes of the World (v. 5.1.1; 17 Aug 2023). Distributed by Smithsonian Institution, compiled by Venzke, E. https://doi.org/10.5479/si.GVP.VOTW5-2023.5.1