大学是向我解释有两个因素;浮力和侵蚀。新鲜的玄武岩岩石浮力是一个主要因素是炎热和干燥,比旧的海洋地壳密度更低。这就是为什么大西洋洋中脊高于周围的海床。与海山效果更加明显,因为他们更热的岩石组成的,需要更长的时间来冷却和湿。年龄很酷,人类使其密度。当他们很酷,他们吸收水分,使其密度。水与岩石仍然冷却,二次矿化发生,填充气体的口袋和其他空间,使岩石的密度。所有这一切导致海底山下沉深入地壳降低它的海拔高度,相对较短的地质时间。同时挂载沉他们也被风化。 This shortens them, and also disguises the depression in the seabed from the sinking mountain with debris from above, since erosion generally slows as the mounts sink deeper. Also, as they move north out of tropical waters and coral growth stops, they stop growing at all. The newer mounts are taller only because they're younger, hotter, and drier, they'll sink and shrink as they age.