HVO reported that two lava lakes at Kilauea were active during 29 June-5 July. The level of the summit lava lake fluctuated deep in the vent inset within the E wall of Halema'uma'u Crater. Periodic measurements indicated that the gas plume from the vent continued to deposit variable amounts of ash nearby. At Pu'u 'O'o, lava from vents near the NE edge of the perched lava lake in the center of the crater floor continued to fill the lake. The lake level fluctuated and overflowed the edges or flowed through rim breaches, sending lava onto the Pu'u 'O'o crater floor. On 3 July inflation caused the crater floor and perched lake rim in the southern half of Pu`u `O`o Crater to rise; those areas continued to rise on 4 July until a large breach on the S rim of the lava lake occurred at midnight. Lava spilled onto the crater floor between the perched rim and the crater wall. The N rim rose briefly but rapidly between 5 and 10 minutes after midnight. The preliminary sulfur dioxide emission rate from all east rift zone sources was calculated at 700 tonnes/day on 30 June.

Geological Summary. Kilauea overlaps the E flank of the massive Mauna Loa shield volcano in the island of Hawaii. 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 Halemaumau 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.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)