Transcript
The Life Cycle of a Hawaiian Volcano
Compared to the 4.5 billion-year-old Earth, The Hawaiian Islands are very young.• Kaua`i emerged about 5 million years
ago• The oldest island Kure, is
approximately 30 million years old.
Deep Submarin
e Stage•An island begins under the ocean. Hot lava pours out of a crack, called a “volcano”•Lava builds a mountain under the sea
Lo`ihi
Shallow Submarine StageLava builds a dome islandThere are no present examples of an island in the Shallow submarine stage
Lo`ihi will be in this stage thousands of years from now
Shield building Stage
•A caldera forms at the top of the dome•A caldera is a crater more than 1 mile in diameter
Landslide Stage•Landslides carried away up to a third of the island away
Capping Stage•Sometimes the caldera is covered by a cap of lava. •Cones form on the sides
Mauna Kea
Erosion stage•The sea and water wear down the island. •Coral starts to grow Ko`olau Mountains, Oahu
Reef growth stage
•The sea is lower, then higher again.•At higher levels more coral grow. •The island sinks
Hanauma Bay, Oahu
Rejuvenation stage
•The sea is lower again•Small cones send out lava•Reefs are made•The islands settles some more
Atoll stage
•The island settles under the sea•Only reefs are left. Kure Atoll
guyot stage
•A flat-topped submerged seamount•Happens when the coral dies and the island sinks beneath the ocean surface
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