On 13 January GeoNet reported that emissions from Whakaari/White Island during the previous 2-3 weeks were characterized as passive, weak-to-moderate, gas-and-steam plumes that sometimes contained ash. The plumes were visible in images from satellite and webcams (at Whakatane and Te Kaha), and during clearer weather conditions a larger plume was occasionally visible from the Bay of Plenty. The New Zealand Met Service also detected ash in the plumes using satellite images on some of the days. According to the Wellington VAAC low-level emissions that contained ash rose 0.6-1 km (2,000-3,000 ft) a.s.l. and drifted N, SW, and S during 9-11 and 13-14 January. GeoNet noted that the ash in the plumes created hazy conditions downwind of the island. The recent activity was consistent with moderate-to-heightened unrest, therefore the Volcanic Alert Level remained at 2 (on a scale of 0-5). At 1230 on 13 January the Aviation Color Code was raised to Orange (the second highest level on a four-color scale). GeoNet stated that the Alert Levels were reflective of the current level of activity, but there was uncertainty due to the current lack of consistent, usable, real-time monitoring data; GeoNet relies on remote cameras and satellite images to monitor Whakaari.

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.

Sources: GeoNet, Wellington Volcanic Ash Advisory Center (VAAC)