Multi-Hazard Mitigation Plan: 08. Lava And Vog

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Chapter 8:Hazard Analysis—Lava and VOG Mauna Loa averaged one eruption every 3.6 years.3s Since 1950, eruption activity on Mauna Loa has slowed considerably. The two eruptions since 1950 include a 1-day summit eruption in 1975 and a 3-week eruption on the northeast rift zone which advanced to within 4 miles of Hilo. Six eruptions from Mauna Loa have reached the ocean since 1859. The 1859 eruption on the northwest flank of Mauna Loa lasted approximately 300 days and reached the ocean north of Kiholo Bay in the North Kona district. Between 1868 and 1950, 5 lava flows have reached the ocean from eruptions on the southwest rift zone of Mauna Loa. These flows traveled quickly with 4 out of the 5 reaching the ocean in 3 to 48 hours.39 These flows entered the ocean in the South Kona and Ka'u districts. The eruption of 1950 destroyed the Ho'okena- mauka village in South Kona with the swiftly flowing lava traveling 14 miles in only 3 hours. Although the lava flow also crossed the area's only highway in two places, the residents of the village escaped unharmed.411 8.2.2 Kilauea Kilauea was almost continuously erupting at its summit caldera from the beginning of historic records up until 1924. Since 1955, most of the activity has occurred along the east rift zone. The latest eruption of the cast rift zone began in 1983 and is still ongoing as of the date of this report. The southwest rift zone has been less active with only 5 eruptions in the past 200 years; the latest was in 1974.41 April 1, 1955 (FEMA DR-32) Hawaii County experienced approximately$12.6 M in damages. About 1,580 hectares (3,900 acres) were covered by 108 million cubic meters (141 million cubic yards) of lava, mostly a'a. Of the covered land, about 450 hectares (1,100 acres) were under cultivation in the Kama'ili, Kehena, Ke'eke'e, Kau'eleau, and Kapoho areas. Approximately 10.1 km (6.3 miles) of public road were buried, as were many kilometers(miles) of cane-field roads. Iwasaki Camp, in Kama'ili near the upper big bend in the road to 'Opihikao, was overrun, but fortunately some of the houses and all personal belongings had been removed. Tragically, surviving remnants of the camp were destroyed on the last day of the eruption, May 26. In all,21 houses were overrun by 'a'a during the eruption January 21, 1960("1960 Kapoho Eruption of Kilauea Volcano Hawaii") (FEMA DR-96) The eruption of Kilauea ended on December 21, 1958; however the reservoir beneath the summit was filled with lava. Tine earthquakes were recorded near the summit of Kilauea and 38 Macdonald,G.A.,A.T. Abbott,F.L.Peterson,Volcanoes in the Sea(2d ed.),University of Hawaii Press, 1983. 39 Hetiker, 1990 40 USGS Fact Sheet 074-97 41 Heliker,1990. 8-10 Hawaii County Multi-Hazard Mitigation Plan