Alaska Volcano Observatory
ASH3D: Ash Cloud Height Forecast for Hypothetical Eruption
- This interactive ash cloud height graphic is the output of a mathematical model of volcanic ash transport in the atmosphere (Ash3D, USGS).
- This model shows expected movement of an ash cloud in the atmosphere for actual or hypothetical eruptions.
- AVO produces this graphic when a volcano is restless by assuming a reasonable hypothetical eruption, in order to provide a pre-eruptive forecast of airspace likely to be affected. During an eruption, AVO updates the forecast with actual observations (eruption start time and duration, plume height) as they become available.
- Colors represent the height of the top of the ash cloud, in feet above sea level, as it drifts downwind.
- Hover over the colored pixels to see the height of the top of the cloud at any location within the model boundary (white box).
- The white bounding box is the model boundary and is based on an estimate of the extent of the cloud before the model is run.
- Options to switch between metric or English units as well as UTC or local time are in the map key.
- To view ash cloud arrival times and duration overhead for communities and airports, click “View Arrival Times” in the key. Communities and airports are only listed if an ashcloud is expected overhead.
- This graphic does not show ashfall deposition on the ground; go here for ashfall graphic. Note that it is possible for ash clouds to move overhead with little or no fallout on the ground.
- For more information about ASH3D, see USGS Open-File Report 2013-1122.
- Return to Great Sitkin activity page for more information on its eruptive status.
Page modified: December 21, 2022 15:07
Contact Information: AVO Web Team
This website is supported by the U.S. Geological Survey under Cooperative Agreement Grant G22AC00137
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