The W vent and dominant E vent in Kilauea's Pu'u 'O'o crater fed a growing lava lake during 11-13 July. Levees built up from overflows during 11-12 July. On the S wall of West Gap pit, intermittent incandescence and fuming from new vents that opened were observed during 13-14 July. On 14 July, the level of the lava lake dropped but remained active near the E vent. On 15 July, the E and W vents erupted small lava flows that drained onto the solidifying lava lake bed. Low lava fountains were observed from West Gap pit. During 15-17 July, lava filled the pit and overflowed into the main crater.

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)