GEOGRAPHY CAPSTONE
OCTOBER 23, 2005 ~ DAY 3
Field Stop 12: Halemaumau Crater
Field Stop 14:
Ocean Entry @ Holei Sea Arch
FIELD STOP 11: SOTHWEST RIFT / GREAT CRACK On day three, the Eau Claire crew began the day by visiting the Soutwest Rift Zone. Kilauea volcanoe developed two rift zones-- the East Rift Zone and the Southwest Rift Zone.
Aerial view of the uppermost Southwest Rift Zone looking towards the northeast.
Photo by J.D. Griggs on March 4, 1985
Location
of the Southwest rift
Map of the five Hawaii Volcanoes: Kohala, Mauna Kea, Hualalai, Mauna Loa and Kilauea. The map
shows the location of the Southwest rift zone and East rift Zone. The red colored regions represent the lava flows erupted
from Kilauea caldera or the rift zones. The yellow colored regions represent the lava flows from present eruption.
How does the rift form?
The rift was formed over time during eruption of Kilauea. Hot magma moved underground from the summmit reservoir in to the rift zone and tearing the crust apart.
An overview of a large groundcrack in the Southwest Rift Zone.
The Southwest Rift road sign.
The Eau Claire
crew standing in the middle of a groundcrack in the Southwest Rift zone. The crack is about 4-5 m deep.
The groundcrack is filled with parallel laminated fine ash deposit.
The crack exposes fragmental deposits of Keanakakoi ash member that were erupted explosively
from Kilauea.
Lavaflows from the 1971 eruption flew into the great crack in the Southwest Rift and
hardened. The photo above shows the hardened lava with sheen.
[Day 3 Home Page] [FS 11: Southwest Rift] [FS12: Halemaumau Crater]
[FS 13: Napau Trail] [FS 14: Holei Sea Arch] [Lava Hike!] [Capstone Home Page]