The Tonga Geological Services reported that an intense thermal anomaly along the SE coast of Home Reef was identified in a 15 June satellite image and showed lava flowing E and expanding the coastline. Thermal anomalies continued to be detected during 16-17 June. On 17 June the Maritime Alert Level was raised to Orange (the second highest level on a four-color scale), the Aviation Color Code was raised to Yellow (the second lowest color on a four-color scale), and the Alert level for residents of Vava’u and Ha’apai remained at Green (the lowest color on a four-color scale). Thermal anomalies persisted and intensified during 17-18 June. On 18 June a satellite images indicated that gas-and-ash plumes drifted SE.

Geological Summary. Home Reef, a submarine volcano midway between Metis Shoal and Late Island in the central Tonga islands, was first reported active in the mid-19th century, when an ephemeral island formed. An eruption in 1984 produced a 12-km-high eruption plume, large amounts of floating pumice, and an ephemeral 500 x 1,500 m island, with cliffs 30-50 m high that enclosed a water-filled crater. In 2006 an island-forming eruption produced widespread dacitic pumice rafts that drifted as far as Australia. Another island was built during a September-October 2022 eruption.

Source: Tonga Geological Services, Government of Tonga