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It always amazes me how young this island is yet how big it is but that might be because I tend to study things that have been around for billions of years! Hawaii Island is less than half a million years old. I'm doing this bit from memory but think HPP was last covered in lava about 500 years ago, other areas south of there much less. On the other hand, yes, it takes several generations between lava flows, so it's not something you probably should worry about in lava zones three and above, but it's a fast moving island, at least geologically speaking...
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I heard it was 660,000 years old give or take a few minutes......
Just noticed the pink filefolder is flaming [
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Puna: Our roosters crow first
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And it's just a matter of time before an earthquake topples San Francisco and probably L.A. but that doesn't seemed to have stopped many from building and moving there.
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Kure is 34 million years old, Kauai is about 4 million years old, BI is about 800K (various books say between 600K-1,000,000) they get this figure by adding up the height of Mauna Loa/Mauna Kea etc at their tallest and then average out the thickness of the average flow and how often they cover ea other on average ie each flow averages 3'-5' thick and covers the same spot every 100-150 years on average...
there used to many more islands above Kure but as they go farther north as the plate moves over the hot spot the water gets colder and coral ceases to live and thrive... thus ea island sink below the surface when it gets to this spot in ocean.... unlike a former volcanic island that became an atoll in warmer waters which grows up (coral) at the same rate as it sinks (volcanic islands slowly sink) so stays just above the sea level.
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save our indigenous and endemic Hawaiian Plants... learn about them, grow them, and plant them on your property, ....instead of all that invasive non-native garbage I see in most yards... aloha
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save our indigenous and endemic Hawaiian Plants... learn about them, grow them, and plant them on your property, ....instead of all that invasive non-native garbage I see in most yards... aloha
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PS plants and animals have evolved in Hawaii for over 50 million years... most people say huh? Kauai is only 4 million years old, its because the flora and fauna has hopped from island to island.. starting well before Kauai was every born... ie Kure etc.
Pre-Man... a plant made it to Hawaii (via water bird or wind) and reproduced and lived on to evolve etc. once every 20,000 years
1 times every 20,000 years a plant made it here and reproduced! think about it thats 10X longer than man has known about these islands
including all the different evolved subspecies there is just slightly over 1,000 different native Hawaiian plants, and NOW 20,000 non-native introduced plants...
thats why many of you cant name more than a 1/2 dozen native plants if that, yet can name hundred of exotic alien invasive plants....
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save our indigenous and endemic Hawaiian Plants... learn about them, grow them, and plant them on your property, ....instead of all that invasive non-native garbage I see in most yards... aloha
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save our indigenous and endemic Hawaiian Plants... learn about them, grow them, and plant them on your property, ....instead of all that invasive non-native garbage I see in most yards... aloha
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quote:
Originally posted by bananahead
...they get this figure by adding up the height of Mauna Loa/Mauna Kea etc at their tallest and then average out the thickness of the average flow and how often they cover ea other on average ie each flow averages 3'-5' thick and covers the same spot every 100-150 years on average...
hey bananahead you got a reference that backs up this assertion?
http://volcanophoto.com
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A good estimate of the Big Island age is about 2 million or so years since Kohala started on the ocean floor - Mauna Kea is about 1.5 million years old (
http://www.iodp.org/scientific-drilling-iodpicdp-7)
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How old are the islands? No one was here when they were built so it is all a guess... What they "prove" today, will be proven wrong tomorrow, its what scientists do..
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piqued my interest:
Until 1970, L#333;#699;ihi was thought to be an inactive volcano that had been transported to its current location by sea-floor spreading. The seafloor under Hawai#699;i is 80–100 million years old and was created at the East Pacific Rise, an oceanic spreading center where new sea floor forms from magma that erupts from the mantle. New oceanic crust moves away from the spreading center. Over a period of 80–100 million years, the sea floor under Hawai#699;i moved from the East Pacific Rise to its present location 6,000 km (4,000 mi) west, carrying ancient seamounts with it. When scientists investigated a series of earthquakes off Hawai#699;i in 1970, they discovered that L#333;#699;ihi was an active member of the Hawaiian-Emperor seamount chain. The age pattern of L#333;#699;ihi's summit craters confirms that volcanism at L#333;#699;ihi has slowly been moving east as L#333;#699;ihi moves away from its origins over the Hawai#699;i hotspot
80 -100 million years
http://en.wikipedia.org/wiki/L%C5%8D%CA%BBihi_Seamount
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Fuelled by Bullwinkle's post and a desire to remove my own ignorance, I have done some reading on the topic. One thing I came across that might be of interest is an image depicting the "Hawaii Hotspot":
http://en.wikipedia.org/wiki/File:Hawaii...iagram.jpg
This is what fuels the generation of the Hawaiian Islands. I was quite surprised at how big it is being depicted. Also interesting was the fact that part of the hotspot still extends as far as Maui.
On another note, the Kahauale'a 2 flow has been updated. Looks like the bulk of the progress is in a more northerly direction. It's burning up a significant bit of old growth (250+ year old) Ohi'a forest. Of course, in 10 years, the Ohi'a will be recolonizing.
Me ka ha`aha`a,
Mike
