Report on Kilauea (United States) — 11 April-17 April 2018
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 11 April-17 April 2018
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2018. Report on Kilauea (United States). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 11 April-17 April 2018. Smithsonian Institution and US Geological Survey.
19.421°N, 155.287°W; summit elev. 1222 m
All times are local (unless otherwise noted)
During 11-17 April HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. The lake level was high, with spattering visible from HVO and Jaggar Museum; by 16 April the lake level was 10 m below the rim of the Overlook crater. Surface lava flows were active above Pulama pali. On 11 April a moderate swarm of over 200 earthquakes occurred at depths of 7-9 km below the summit. The largest event was a M 2.4. Seismicity returned to background levels at 0230. Three minor ledge collapses were detected on 12 April, one at 1157 and two just after 1830. Surface lava flows were active above Pulama pali; on 13 April most scattered breakouts were within 2.2 km from Pu'u 'O'o Crater, and one was about 5 km away.
Geologic Background. Kilauea, which overlaps the E flank of the massive Mauna Loa shield volcano, has been Hawaii's most active volcano during historical time. Eruptions are prominent in Polynesian legends; written documentation extending back to only 1820 records frequent summit and flank lava flow eruptions that were interspersed with periods of long-term lava lake activity that lasted until 1924 at Halemaumau crater, within the summit caldera. The 3 x 5 km caldera was formed in several stages about 1500 years ago and during the 18th century; eruptions have also originated from the lengthy East and SW rift zones, which extend to the sea on both sides of the volcano. About 90% of the surface of the basaltic shield volcano is formed of lava flows less than about 1100 years old; 70% of the volcano's surface is younger than 600 years. A long-term eruption from the East rift zone that began in 1983 has produced lava flows covering more than 100 km2, destroying nearly 200 houses and adding new coastline to the island.