During 9-15 May, lava from Kīlauea continued to flow SE across a lava delta into the ocean at the Kamokuna entry. Incandescence was visible from several vents in the Puʻu ʻŌʻō crater and from breakouts on, above, and at the base of the Pūlama pali fault scarp. Earthquake activity was scattered at the S edge of the summit, upper E rift zone between Puhimau and Pauahi craters, and S-flank areas. On 10 May, approximately 6.5 hectares (16 acres) of the East Laeʻapuki bench collapsed, starting from the E-side and moving progressively westward. Each section of collapse generated a steam plume, occasionally blackened with rock dust, which rose to about 0.1-0.3 km (200-1,000 ft) a.s.l. The plumes resulted from the explosive interaction between seawater and incandescent rock exposed immediately after each section collapsed. On 11 May, HVO scientists surveyed the collapse and mapped cracks inland of the sea cliff. Rock fragments covered a 1.2 hectare (3 acre) area.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Geological Summary. Kīlauea overlaps the E flank of the massive Mauna Loa shield volcano in the Island of Hawaiʻi. 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 Halemaʻumaʻu 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.