Lava continued to flow down the Pulama pali and across the coastal flat. On 25 April a small stream of lava reached the sea for the first time since late January. The lava stopped trickling into the sea on 29 April. On that day an unstable block of the lava bench fell into the sea, producing a loud noise and generating an explosion that tossed rocks onto dry land. A M 4.4 earthquake on the afternoon of 25 April was followed by a few small aftershocks during the rest of the week. A swarm of long-period earthquakes that began on 18 April continued through at least 27 April. The tilt at the summit was neither flat nor consistently in one direction or the other. Tiltmeters along the east rift zone indicated that there was no significant deformation.

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)