|MadSci Network: Earth Sciences|
Plate tectonics carry the islands formed by the Hawaii hotspot away to the northwest. These islands also subside back into the ocean over time-- say hundreds of thousands of years--once they have been transported away from the uplifting influence of the hotspot. So for example the islands of Maui, Lanai, and Oahu were originally all part of the same island that was created over the hotspot. This larger island has sunk down leaving the individual islands we see today. The Big Island (Hawaii) is now "over" the hotspot but it will also move off to the Northwest and presumably sink down over time. The next one in the chain (Loihi) is still under construction to the Southeast of Hawaii and hasn't emerged from the ocean yet, so it is called a "seamount". We expect to see it above the ocean in the next 100,000 years or so. Visit this website to read more about the Hawaii chain that has been formed in this way, where many of the older islands are now below sea level: http://pubs.usgs.gov/gip/dynamic/Hawaiian.html From there you can also visit a more general page on hotspots also provided by the US Geological Survey (USGS): http://pubs.usgs.gov/gip/dynamic/hotspots.html Finally a book suggestion: Ask your librarian for help locating some books on this great topic. A recent book published on this topic with a lot more technical detail is called "Oceanic Hotspots: Intraplate Submarine Magmatism and Tectonism". Books will give you a lot better picture than websites! cheers -Rob http://robfatland.net
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