And the other islands, well, the farther away from the plume they are now, the older they are, and the longer ago their volcanoes went dormant or extinct.
而其他島嶼,它們現在離地幔柱越遠,形成的時間就越長,它們的火山沉寂或熄滅的時間就越早。
Incidentally, volcanic islands may seem small,
偶爾火山島看上去也許很小,
but the island known as the Big Island Hawaii
但是像夏威夷這樣知名的大島
is one of the tallest topographic features on the planet, more than five kilometers from the sea floor to the ocean surface,
是地球上最高的地形特征之一,從海床到海平面超過5千米,
and almost that much again, up to its highest peak.
從海平面到其頂峰差不多也有那么高。
That’s nearly ten kilometers from ocean floor to the highest point on the island, which makes it taller even than Mount Everest.
從海床到這座島的最高點將近有一萬米,這使得它甚至比喜馬拉雅山還要高。
So, you can imagine the huge amounts of magma, or lava, that’ve flowed up to form even just this one island, much less the whole chain of islands.
所以不難想象出噴涌而出形成這一座島的巖漿數量之巨大,更不用說這整個群島。
Now, the Plume Hypothesis provides a pretty elegant explanation for a volcanic anomaly, like the Hawaiian Islands.
地幔柱理論為像夏威夷群島這樣的異常火山提供了一個非常得體的解釋。
But, while it’s hypothetically attractive, there’s very little direct evidence to support the theory, because so far,
但是,雖然這個理論很有吸引力,但是幾乎沒有直接證據能夠支持這一理論,因為到目前為止,
no one’s been able to actually observe what’s happening that far beneath the Earth’s crust.
沒人能夠真正觀察到那么深層的地殼在發(fā)生什么。
Some studies have been done, seismographic, geochemical, where the data’s consistent with the model, but they aren’t definitive proof.
人們進行了一些地震學、地球化學方面的研究,這些研究中得出的數據和模型是一致的,但是它們不是最可靠的證據。