The Hawaiian Volcano Observatory (HVO) reported that the eruption within Kilauea’s Kaluapele summit caldera, characterized by episodic fountaining and intermittent spatter at two vents along the SW margin of Halema’uma’u Crater, continued at variable levels during 16-22 July. Minor incandescence at the N vent and on the N vent cone was sporadic during 16-18 July. Slow slumping of the eruptive cone continued. After an hour of strong incandescence at the N vent late on 19 July, spattering began at 0355 on 20 July, followed soon after by low dome fountaining less than 30 m high. Lava overflowed the vent at around 0411. The dome fountains transitioned to vertical lava fountains that exceeded 60 m by 0515 and 100 m by 0525. The fountain was wide and comparatively shorter than during other recent fountaining episodes. Spattering and low fountaining started at the S vent at around 0600 and ended at noon. Throughout the day multiple lava flows advanced onto the crater floor and traveled as far as 2.5 km. The N vent ceased erupting at 1835, after 13 hours of sustained fountaining. The eruptive episode produced an estimated 7 million cubic meters of lava covering about 80 percent of the crater floor. Considerably less tephra was produced compared to recent episodes of lava fountaining. The Volcano Alert Level remained at Watch (the third level on a four-level scale) and the Aviation Color Code remained at Orange (the third color on a four-color scale).

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)