On 22 January GeoNet Data Centre reported that unrest at White Island continued. A volcanologist visiting the area on 21 January observed that hydrothermal activity in the small "hot lake" had increased. The lake surface "domed up" from rising steam and gas, that also brought large amounts of sediment to the surface, often with a vivid white steam-and-gas "flashing" from around the base. Stronger events periodically occurred. The report noted that the activity had been increasing since late 2012 and was now semi-continuous. The Aviation Colour Code remained at Yellow (second lowest on a four-color scale) and the Volcanic Alert Level remained at 1.

Geological Summary. The uninhabited Whakaari/White Island is the 2 x 2.4 km emergent summit of a 16 x 18 km submarine volcano in the Bay of Plenty about 50 km offshore of North Island. The island consists of two overlapping andesitic-to-dacitic stratovolcanoes. The SE side of the crater is open at sea level, with the recent activity centered about 1 km from the shore close to the rear crater wall. Volckner Rocks, sea stacks that are remnants of a lava dome, lie 5 km NW. Descriptions of volcanism since 1826 have included intermittent moderate phreatic, phreatomagmatic, and Strombolian eruptions; activity there also forms a prominent part of Maori legends. The formation of many new vents during the 19th and 20th centuries caused rapid changes in crater floor topography. Collapse of the crater wall in 1914 produced a debris avalanche that buried buildings and workers at a sulfur-mining project. Explosive activity in December 2019 took place while tourists were present, resulting in many fatalities. The official government name Whakaari/White Island is a combination of the full Maori name of Te Puia o Whakaari ("The Dramatic Volcano") and White Island (referencing the constant steam plume) given by Captain James Cook in 1769.

Source: GeoNet