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Aerial view of active part of west branch of PKK flow just starting to drop over Paliuli. Incandescence indicates spot where lava is moving over the crest of the pali. Two older, but still young, fingers have reached the base of Paliuli in the past week. Pulama pali is in background.
Lava in tube inside flow with `a`a crust. It is often mistakenly claimed that lava tubes form only in flows with pahoehoe crust. In reality, tubes form in basaltic lava flows before they become either pahoehoe or `a`a, because those terms apply only to solid crust, not liquid lava.