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USGS · 70013424

Olokele rock avalanche, island of Kauai, Hawaii

B.L. Jones·S.S.W. Chinn·J.C. Brice
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Abstract

In October 1981 a mass of rock and soil having an estimated volume of 500,000 m 3 fell as a rock fall-avalanche from a steep slope 800 m high near the head of Olokele Canyon on the island of Kauai, Hawaii. Boulders were launched into the air from a bench on the slope for a downstream distance of about 850 m. The velocity of the avalanche was rapidly diminished by impact against the valley sides, and it became a muddy debris flow that traveled 4.6 km downstream, severely eroding the valley sides. The volume of debris deposited on the canyon bottom is estimated to be 2,500,000 m 3 , or about four times the volume derived from the slope. Slope failure is attributed to gradual undercutting and loss of shear strength in beds of weathered ash and to joints in a thick basaltic cap rock.

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B.L. Jones, S.S.W. Chinn, J.C. Brice. 1984. Olokele rock avalanche, island of Kauai, Hawaii. https://doi.org/10.1130/0091-7613(1984)12%3C209%3Aoraiok%3E2.0.co%3B2

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