HVO reported that lava effusion at the vent of the main cone in the lower W wall of Kilauea’s Halema`uma`u Crater continued intermittently during 26 January-1 February. The lake level fluctuated, reflecting variable lava supply to the lake and periods of inflation and deflation. Lava effused from the vent during 26-28 January, and the W part of the lake was active along with a small pond N of the W vent cone. A few small flows oozed out from the N margin of the lake and an area of spattering in the E part of the crater built a new, small, steep-sided cone. Field crews working near the crater on 27 January heard loud gas-jetting sounds from the new cone.

Active lava was no longer visible in the crater by 0800 on 29 January. During 29-30 January the lake was mostly crusted over, though foundering of the crust in the E part of the lake exposed lava and circulating lava was occasionally visible in the small pond N of the main cone. Lava again began flowing from the main cone just before 2130 on 30 January. Lava quickly filled the ponded area just to the N and flowed into the lake. The lake began to rise and overflowed the S margins by midnight, and the N margins by 0500 on 31 January. Lava flows from the S part of the lake fed flows that traveled SE along the walls of the crater until 1100. Multiple ooze outs from the N margin continued through 1 February. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively.

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)