The Hawaiian Volcano Observatory (HVO) reported that the eruption within Kilauea’s Kaluapele summit caldera, from vents along the SW margin of Halema’uma’u Crater, continued at variable levels during 4-11 March. Lava fountaining and lava flow effusion from cones at both the N and S vents began around 0730 on 4 March and continued at variable levels through the day. Lava fountains at the N vent were rising over 100 m by 1430. At around the same time low dome fountains began rising from the S vent and lava flows advanced onto the crater floor. The fountains started to grow taller by 1500 and by 1520 they were 100-130 m tall, the same height as fountains at the N vent. Fountains at the S vent continued to rise and approached 180 m tall, while fountains at the N vent decreased in height. In addition to the activity at the N and S vents, small breakouts were visible on the rootless flows near the September 2023 vents on the down-dropped block in the E part of Halema’uma’u. Fountaining at the N vent ceased at 2026. Fountains at the S vent dropped to 90-120 m and continued to be active overnight. The N vent produced occasional bursts of spatter. Sustained lava fountains at the S vent decreased to 30-60 m during 0300-0430 on 5 March. Fountaining at the S vent increased at around 0800, and the N vent briefly resumed fountaining and erupting lava flows during 0842-0911. Lava flows covered more than two thirds of the crater floor. Activity at both vents ceased by 1030. Sulfur dioxide emission averaged approximately 35,000 tonnes per day (t/d) during the period of high fountaining on the afternoon of 4 March, then decreased to 20,000 t/d during lower fountaining on the morning of 5 March, and to 1,800 t/d by the afternoon. The flows from the N and S vents were active during 5-6 March with ooze outs and small crustal overturns, but the activity had ceased by the morning of 7 March. Sulfur dioxide emission averaged 1,000 t/d on 7 March.

Incandescence from both the N and S vents was visible during 8-10 March. At about 0130 on 10 March small, sporadic, spatter fountains at the N vent rose 5-10 m high and continued to intensify until 1835. Spattering was visible overnight. Lava flows emerged from the N vent at 0236 on 11 March and tall fountaining started 10 minutes later. By 0330 the fountains were 120-150 m tall and lava covered up to one-third of the crater floor. Lava flows unrelated to the activity at the N and S vents continued to spread out on the down-dropped block in the E part of the crater during 5-10 March and were possibly fed from by older stored lava from beneath the crater floor. 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)