The Aviation Alert level for Tonga's Home Reef volcanic activity was raised from Yellow to Orange this morning as the ongoing eruption has elevated to ash composition, but Tonga Geological Services (TGS) said there is low risk to the Vava'u and Ha'apai Communities.

Ash height is up to 3km above sea level and drifting 50km North and Northeast and 70km Eastward direction.

Aviation Colour Code Orange indicates that a volcanic eruption is underway but with little or no ash being produced.

At 9:30am today, Tuesday (20 September), the TGS reported there had been a total of seven eruption events in the last 24 hours, compared to two events in the previous 24 hours period. There have been a total of nine eruptions in the last 48 hours – mostly steam and gas eruptions.

The last eruption was of steam and ash composition. This was captured by VOLCAT at 8:50 am local time this morning and HIMAWARI-8 AHI.

This is the 10th day since the first eruption was detected by VOLCAT at 1:39am, on 10 September 2022.

TGS advised the Aviation Community to lookout and take caution when flying through this airspace

There is “Low risk to the Vava’u and Ha’apai Communities, visible ashfall is forecasted to fall within a few kilometres of the vent and others within the sea.

“Advice to all mariners to travel 4 km away from Home Reef and lookout for ashfall.

Hazard Zones for mariners are applied around the area.

Aviation Colour Codes

The Aviation Colour Code system is based on four colours and is only intended for use by the civil aviation community. The system is defined by the International Civil Aviation Organization(ICAO), and GNS Science allocates the levels for the volcanoes.

The Aviation Colour Codes provide the aviation community with information about volcanic activity and the potential presence of volcanic ash in the atmosphere. This information enables the aviation sector to make decisions about aviation safety and flight routes, especially for long-haul flights.