The Tonga Geological Services reported no indications of activity at Home Reef during 2-16 August. A comparison of satellite images from 15 July and 11 August showed new deposits of eroded material at the NW coastline and sharp edges along the SE coastline from wind and wave action. Yellow sulfur deposits in and around the main crater were more prominent in the 11 August image, suggesting that emissions of steam and sulfur dioxide gas were continuing; a diffuse plume was visible in both images. Discolored water around the island was visible in both images. The Aviation Color Code remained at Yellow (the second lowest level on a four-level scale, the Maritime Alert Level remained at Orange (the third level on a four-level scale) with advice to stay at least 2 nautical miles (3.7 km) from the island, and the Alert Level for residents of Vava’u and Ha’apai remained at Green (the first level on a four-level scale).

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