The Tonga Geological Services reported that an eruption at Home Reef was ongoing during 3-9 July based on the detection of thermal anomalies. Daily thermal anomalies were identified in infrared satellite images, though the number and intensity of the anomalies were variable. A satellite image acquired at 0720 on 4 July showed a small ash cloud drifting N at 2 km a.s.l. A plume of discolored water originating along the central part of the E coast, at the N end of the new lava flow, was visible in a 5 July satellite image drifting SE. The Maritime Alert Level remained at Orange (the second highest level on a four-color scale) and mariners were advised to stay 4 km away from the island, the Aviation Color Code remained at 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).

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