According to a news report from 31 January, Tokua airport (20 km SE) reopened after being closed due to ash from Rabaul.

RVO reported that during 1-3 February Rabaul was mostly quiet, although occasional explosions produced light gray ash plumes that rose as high as 500 m above sea level and drifted E and ESE. At 1151 on 3 February an explosion produced a dense, dark ash plume that slowly rose 2 km above sea level and drifted ENE. Ash was observed falling on South Daughter (Turangunan, ~2 km to the E) and to the N of it. Dark gray ash emissions continued for the next 15-20 minutes. During the afternoon of 3 February through the morning of 4 February light gray ash emissions rose at irregular intervals and drifted E and ESE. White vapor plumes rose from the crater in between the ash emissions.

Geological Summary. The low-lying Rabaul caldera on the tip of the Gazelle Peninsula at the NE end of New Britain forms a broad sheltered harbor utilized by what was the island's largest city prior to a major eruption in 1994. The outer flanks of the asymmetrical shield volcano are formed by thick pyroclastic-flow deposits. The 8 x 14 km caldera is widely breached on the east, where its floor is flooded by Blanche Bay and was formed about 1,400 years ago. An earlier caldera-forming eruption about 7,100 years ago is thought to have originated from Tavui caldera, offshore to the north. Three small stratovolcanoes lie outside the N and NE caldera rims. Post-caldera eruptions built basaltic-to-dacitic pyroclastic cones on the caldera floor near the NE and W caldera walls. Several of these, including Vulcan cone, which was formed during a large eruption in 1878, have produced major explosive activity during historical time. A powerful explosive eruption in 1994 occurred simultaneously from Vulcan and Tavurvur volcanoes and forced the temporary abandonment of Rabaul city.

Sources: Rabaul Volcano Observatory (RVO), Radio Australia