Honolulu Volcanic Series
- The rejuvenation stage of Koolau volcano
- Vents scattered throughout southeast end of Koolau
- The most recent rejuvenation is the Koko Rift
Adapted from Macdonald et al., 1983.
Koko Rift
Hanauma Bay
Rejuvenation Stage Volcanism
- Extends from Manana, past Hanauma Bay, and continues offshore
- Eruptions were violent, and took place offshore
- 40,000 - 50,000 year old vents
- Occurs after the shield building stages of Hawaiian volcanoes
- Associated with Pele's travels across the island chain
- Two models to explain the process
- "Curved" or "hand-wrestling" bay
- Tuff cone
- Coral reef formed after wall collapse
Melting away from the hot spot
Mantle Plume Model
The 9 Life Stages
of Hawaiian Volcanoes
Drawing by, B. Taylor, SOEST.
Life Stages of a
Hawaiian Volcano
- Some volcanoes skip steps
- Others stay in a particular one for a long time
- Or for only a brief period
Hot "spot" as a hot "column"
The Hawaiian Hot Spot
- Hot spot - an upward-moving cylinder of solid mantle material
- Lots of melting in the center (very hot)
- Not as much melting on the outside (cooler)
- The Pacific Plate moves over the top of the hot spot
- Hot spot gets stretched
Geology of Hanauma Bay
Presented by, Kahua A'o: A Learning Foundation