---
type: Domain Concept
title: Volcanic ash advisories
description: Current global aviation advisories for observed volcanic ash emissions.
tags: [catalog, volcano, aviation, vaac, snapshot]
visibility: public
---

# Meaning

`volcanic-ash-advisories` is a global, current-state Data Product for volcanic
ash that can affect aviation. It reports the latest advisory for each volcano,
not a history of eruptions and not a complete catalogue of volcanic activity.

# Provider and coverage

The initial Provider is the public Australian Bureau of Meteorology relay of
the nine ICAO Volcanic Ash Advisory Centres (VAACs). Together the centres cover
the world's flight-information regions. The channel refreshes every 15 minutes
and retains only observations no older than 26 hours.

# Contract

Each feature is a Point at the advisory's stated volcano position. Required
properties preserve the issuer and identity: `volcano_name`, `vaac`,
`advisory_number`, and `advisory_time`. Optional details retain the ash-cloud
description, eruption details, information sources, and next-advisory time.

# Boundaries

An advisory is issued for ash hazards, so an eruption without observed or
reported airborne ash may be absent. The product is informational and is not a
substitute for official flight planning, NOTAMs, SIGMETs, or operator safety
procedures. Smithsonian weekly volcanic activity remains a separate product for
catalogue identity and reviewed context.