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Volcano-alert notifications are produced by Volcano Observatory scientists and are based on analysis of data from monitoring networks, direct observations, and satellite sensors.
They are issued for both increasing and decreasing volcanic activity and include text about the nature of the unrest or eruption and about potential or current hazards and likely outcomes. Scientists describe a volcano's status using the alert levels and color codes and issue different types of notifications to address specific information needs. All notifications are publicly available.
NOTIFICATION TYPES
Volcano Activity Notice (VAN)
Announces alert-level changes or significant volcanic activity within an alert level; covers all volcanic hazards—lahars (volcanic mudflows), lava flows, ashfall, airborne ash, pyroclastic flows.