Hawaiigreenspun.com : LUSENET : Introductory Geology, Oswego State : One Thread
I was wondering, if Hawaii was formed by a plate moving over a hot spot than why are the oldest islands so small compared to the new, younger islands. Could it be because of weathering and erosion. It just doesn't make sense that the older island are sooo small compared to the younger ones.
-- craig garrison (email@example.com), March 14, 2001
in class we learned that there is millions of years diffrence between each of the islands. that would account for a great deal of errosion especially considering the location, warm and wet. the magma of the volcanoes also can contribute to the erosion because the magma is not rich in the stronger element of silica. silica has very strong bonding and may slow errosion, while the hawaian islands are made of basalt magma.
-- kelly cleason (firstname.lastname@example.org), March 16, 2001.
The hawaiin islands have been eroded through time and also the silica content is low in mafic magma. Yet there is another reason for the smallness of the older islands, this is due to the temperature of the rock. As rock oceanic rock cools it looses bouancy and sinks. this is why the islands that are old seem so small.
-- Adam (email@example.com), March 29, 2001.