During 31 March-6 April, HVO reported incandescence from a 60-m-wide active lava surface about 200 m below a vent in the floor of Kīlauea's Halemaʻumaʻu crater. The lava surface circulated and both rose and drained through a pit in the cavity floor; a few times the level fluctuated between 235 and 260 m below the surface. Plumes from the vent drifted mainly SW, dropping small amounts of ash downwind. The sulfur dioxide emission rate at the summit on 31 March was 1,400 tonnes per day, the highest recorded in 2010. The rate on 1 and 2 April was 1,000 and 650 tonnes per day, respectively.

Lava from beneath the Thanksgiving Eve Breakout (TEB) and rootless shield complex flowed SE through the upper portion of a lava tube system and broke out onto the surface. Lava flows advanced E, and then SE down Pūlama pali.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Geological Summary. Kīlauea overlaps the E flank of the massive Mauna Loa shield volcano in the Island of Hawaiʻi. Eruptions are prominent in Polynesian legends; written documentation since 1820 records frequent summit and flank lava flow eruptions interspersed with periods of long-term lava lake activity at Halemaʻumaʻu crater in the summit caldera until 1924. The 3 x 5 km caldera was formed in several stages about 1,500 years ago and during the 18th century; eruptions have also originated from the lengthy East and Southwest rift zones, which extend to the ocean in both directions. About 90% of the surface of the basaltic shield volcano is formed of lava flows less than about 1,100 years old; 70% of the surface is younger than 600 years. The long-term eruption from the East Rift Zone between 1983 and 2018 produced lava flows covering more than 100 km², destroyed hundreds of houses, and added new coastline.