HVO reported that two lava lakes at Kilauea were active during 15-21 June. The level of the summit lava lake fluctuated but remained mostly stable deep in the vent inset within the E wall of Halema'uma'u Crater. A gas plume from the vent drifted SW, depositing variable amounts of ash and fresh spatter nearby. On 17 June a heated brown plume rose from a spattering source on the SE edge of the lake; the ejecta were primarily fresh spatter bits suggesting that the plume derived from a partial collapse of the spattering source or a small rockfall.

At Pu'u 'O'o, lava from vents near the W and NE edges 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. A small shield had built up against the SW crater wall on the W side of the lake. There was also minor lava activity from at least one source at the base of the SW crater wall.

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)