Instructions for the completion of the Ashtam Format
1.1 The ASHTAM provides information on the status of activity of a volcano when a change in its activity is, or is expected to be of operational significance. This information is provided using the volcano level of alert colour code given in 3.5 below.
1.2 In the event of a volcanic eruption producing ash cloud of operational significance, the ASHTAM also provides information on the location, extent and movement of the ash cloud and the air routes and flight levels affected.
1.3 Issuance of an ASHTAM giving information on a vol- canic eruption, in accordance with section 3 below, should not be delayed until complete information A) to K) is available but should be issued immediately following receipt of notification that an eruption has occurred or is expected to occur, or a change in the status of activity of a volcano of operational significance has occurred or is expected to occur, or an ash cloud is reported. In the case of an expected eruption, and hence no ash cloud evident at that time, items A) to E) should be completed and items F) to I) indicated as “not applicable”. Similarly, if a volcanic ash cloud is reported, e.g. by special air-report, but the source volcano is not known at that time, the ASHTAM should be issued initially with items A) to E) indicated as “unknown”, and items F) to K) completed, as necessary, based on the special air-report, pending receipt of further information. In other circumstances, if information for a specific field A) to K) is not available indicate “NIL”.
1.4 The maximum period of validity of ASHTAM is 24 hours. New ASHTAM must be issued whenever there is a change in the level of alert.
2. Abbreviated heading
2.1 Following the usual AFTN communications header, the abbreviated heading “TT AAiiii CCCC MMYYGGgg (BBB)” is included to facilitate the automatic processing of ASHTAM messages in computer data banks. The explanation of these symbols is:
TT = data designator for ASHTAM = VA;
AA = geographical designator for States, e.g. NZ = New
Zealand (see Location Indicators (Doc 7910), Part 2, Index to Nationality Letters for Location Indicators);
iiii = ASHTAM serial number in a four-figure group;
CCCC = four-letter location indicator of the flight information region concerned (see Location Indicators (Doc 7910), Part 5, addresses of centres in charge of FIR/UIR);
MMYYGGgg = date/time of report, whereby:
MM = month, e.g. January = 01, December = 12 YY = day of the month
GGgg = time in hours (GG) and minutes (gg) UTC;
(BBB) = Optional group for correction to an ASHTAM message previously disseminated with the same serial number = COR.
Note. Brackets in (BBB) are used to indicate that this group is optional.
Example: Abbreviated heading of ASHTAM for Auckland Oceanic FIR, report on 7 November at 0620 UTC:
VANZ0001 NZZO 11070620
3. Content of ASHTAM
3.1 Item A — Flight information region affected, plain- language equivalent of the location indicator given in the abbreviated heading, in this example “Auckland Oceanic FIR”.
3.2 Item B — Date and time (UTC) of first eruption.
3.3 Item C — Name of volcano, and number of volcano as
listed in the ICAO Manual on Volcanic Ash, Radioactive Material and Toxic Chemical Clouds (Doc 9691), Appendix H, and on the World Map of Volcanoes and Principal Aeronautical Features.
3.4 Item D — Latitude/Longitude of the volcano in whole degrees or radial and distance of volcano from NAVAID (as listed in the ICAO Manual on Volcanic Ash, Radioactive Material and Toxic Chemical Clouds (Doc 9691), Appendix H, and on the World Map of Volcanoes and Principal Aeronautical Features).
3.5 Item E — Colour code for level of alert indicating volcanic activity, including any previous level of alert colour code as follows:
|Level of alert colour code||Status of activity of volcano|
|RED ALERT||Volcanic eruption in progress. Ash plume/cloud reported above FL 250.
Volcano dangerous, eruption likely, with ash plume/cloud expected to rise above FL 250.
|ORANGE ALERT||Volcanic eruption in progress but ash plume/cloud not reaching nor expected to reach FL 250.
Volcano dangerous, eruption likely but ash plume/cloud not expected to reach FL 250.
|YELLOW ALERT||Volcano known to be active from time to time and volcanic activity has recently increased significantly, volcano not currently considered dangerous but caution should be exercised.
(After an eruption, i.e. change in alert to yellow from red or orange.) Volcanic activity has decreased significantly, volcano not currently considered dangerous but caution should be exercised.
|GREEN ALERT||Volcanic activity considered to have ceased and volcano reverted to its normal state.|
Note. The colour code for the level of alert indicating the status of activity of the volcano and any change from a previous status of activity should be provided to the area control centre by the responsible vulcanological agency in the State concerned, e.g.“RED ALERT FOLLOWING YELLOW” OR “GREEN ALERT FOLLOWING ORANGE”.
3.6 Item F — If volcanic ash cloud of operational significance is reported, indicate the horizontal extent and base/top of the ash cloud using latitude/longitude (in whole degrees) and altitudes in thousands of metres (feet) and/or radial and distance from source volcano. Information initially may be based only on special air-report, but subsequent information may be more detailed based on advice from the responsible meteorological watch office and/or volcanic ash advisory centre.
3.7 Item G — Indicate forecast direction of movement of the ash cloud at selected levels based on advice from the responsible meteorological watch office and/or volcanic ash advisory centre.
3.8 Item H — Indicate air routes and portions of air routes and flight levels affected, or expected to become affected.
3.9 Item I — Indicate closure of airspace, air routes or portions of air routes, and availability of alternative routes.
3.10 Item J — Source of the information, e.g. “special air-report” or “vulcanological agency”, etc. The source of infor- mation should always be indicated, whether an eruption has actually occurred or ash cloud reported, or not.
3.11 Item K — Include in plain language any operationally significant information additional to the foregoing.
Source: ICAO Annex 15