HVO reported that the eruption on the floor of Kilauea’s Halema'uma'u Crater continued during 14-20 June. Activity was characterized by effusion primarily from the vent on the SW wall of the crater, circulation within the crater lakes, slow rise of the crater floor, eruptive tremor, and elevated sulfur dioxide levels (4,500-6,300 tonnes per day). Lava flows from vents at the base and top of a cone on the SW wall of Halema'uma'u entered the lava lake in the far SW portion of the crater; intermittent spattering from the cone was visible at night. Other eruptive vents within the SW lava lake (previously dome fountains) had ceased by 13 June. The surface of the SW lava lake slowly rose about 0.5 m per day during 13-15 June. Additionally, lava circulation continued within the central basin. At 0800 on 15 June the top of the SW wall cone collapsed, leading to nearly constant spattering from the top vent and a change in activity from the base vent. The central basin level has been dropping relative to the rising crater floor (due to lava accumulation underneath), allowing several flows from the SW lava lake to cascade into the basin.

By 16 June, renewed activity on the SW wall was producing vigorous fountaining to at least 10 m high with some higher spatters, with lava flowing into the SW lake. This activity continued into 19 June as the crater floor continued to rise, circulation in central basin slowed, and flows from the base of the SW wall cone changed paths. Around 1600 on 19 June activity rapidly declined, shown by a drop in the SW lake surface, decreased seismicity, and a transition to inflationary tilt from the deflationary trend of the previous two days. Seismic activity remained low and on 20 June HVO reported that the eruption had paused.

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)