Sea Cliff at Kamokuna Lava Ocean Entry Highly UnstableFebruary 2, 2017, 2:22 PM HST · Updated February 2, 2:22 PM U.S. Geological Survey Hawaiian Volcano Observatory (Volcanic Activity Notice) · 0 Comments
Kīlauea Volcano’s episode 61g lava flow is still active and entering the ocean at Kamokuna on the volcano’s south coast. Recent observations of the ocean entry indicate growing instability of the adjacent sea cliff. Potential collapse of the cliff poses an extreme danger to anyone in the closed area on land, as well as to boats near the ocean entry.
On Jan. 25, Hawaiian Volcano Observatory geologists noted an extensive crack running parallel to the sea cliff about 16-33 ft. behind the stream of lava at the Kamokuna ocean entry. Ground inspection of this crack by HVO geologists on Jan. 28 showed about 1 foot of separation across the crack.
Four days later, on Feb. 1, this crack had widened to about 2.5 feet. The seaward block bounded by this crack was visibly moving up to about 1/2 inch, possibly in response to explosions below the ocean entry as hot lava mixed with cool ocean water. In addition, ground shaking could be felt up to several hundred meters (yards) away.
These observations show that this portion of the sea cliff is highly unstable and could collapse into the ocean with no warning.
Sudden collapse into the ocean of a slab of sea cliff about 90 ft high and about 490 ft or more in length would create a significant wave that would travel rapidly out to sea. It would also could shower the immediate area with blocks of hot rock and fragments of molten lava. It could also prompt more powerful explosions as the 61g lava tube is further exposed.
HVO continues to monitor the situation and will issue further updates as new information becomes available.