View is from overlook across Crater Rim Drive from Keanakako`i Crater toward the
west. Halema`uma`u is visible in upper right.
This eruptive fissure was active briefly during an eruption in July 1974. Note prominent spatter ramparts on right, and subdued rampart on left, built by the ejection of lava along the fissure. The fissure of the August 1971 eruption is just out of view to the right. Both eruptions produced a lava flow that spilled into the caldera and covered a large part of the eastern caldera floor. The smooth texture of the surface on the lip of the fissure (lower right) is evidence that lava drained back into the fissure toward the end of the 1974 eruption.
Lava erupted from the July 1974 fissure rushed down a narrow gully trending to the left just this side of the subdued spatter rampart. Calculations based on run-up features in the lava flow along the course of the gully suggest a flow velocity greater than 20 km/hr.