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Mauna Ulu trench, w/crater in background. Looking west, May 25, 1972

Detailed Description

Mauna Ulu trench, with crater in background. Looking west, May 25, 1971. The trench developed by collapse along the lava tube between Mauna Ulu and 'Alae, but the process was very complicated. It was separated from the summit crater by a partition of rubble. The floor of the trench, about 530 m (1,750 ft) long and from 40 to 60 m (130 to 200 ft) wide, was made of rubble, but heat shimmer indicated that lava was near the surface. Lava moved from the lake in the crater along the trench before entering a lava tube and flowing into 'Alae.