For a long time, geologists were perplexed about the formation of the Nīnole Hills on the SE flank of Mauna Loa. Are they remnants of an older summit of Mauna Loa or its predecessor volcano, Mohokea? The Nīnole Hills are a failed rift and mass-wasting events on Mauna Loa's western flank approximately 127,000 most likely caused the abandonment of the rift, leading to the westward migration of Mauna Loa's present SW Rift Zone.
Helens' summit after several small explosive eruptions opened pit craters. The smaller of the two pit craters was formed first on March Subsequent eruptions opened the farther crater. The two craters subsequently merged.
Soufriere Hills volcano erupting on the Caribbean Is. of Montserrat on 3 wks after this photograph was taken, the volcano dome experienced another major partial collapse, triggering hrs of eruptions/ pyroclastic flows (APPhoto/Wayne Fenton)
Bazman (Kuh-e Bazman) is a 3490-m-high stratovolcano in a remote and arid region in SE Iran. A well-preserved, 500-m-wide crater caps the summit of the volcano. Its satellitic lava domes have been the source of fresh-looking viscous lava flows, including the prominent one with dramatic flow levees at the lower left. No historical eruptions are known from Bazman, but minor fumarolic activity has been reported.