The ROV ROPOS gently flew into a small collapse basin marked by pillars, arches and isolated columns of basalt. These areas form as lava drains out from deep lava pools. The surface of the lava lake or channel very rapidly cools as it interacts with near freezing seawater. As the lava drains out, the roof is not strong enough to maintain its weight, and collapses into a pile of talus.
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