最近火山活动的证据在超缓慢扩散的Gakkel山脊上
M H Edwards1, G J Kurras, M Tolstoy
1Hawaii Institute of Geophysics and Planetology, School of Ocean and Earth Science and Technology, University of Hawaii at Manoa, 96822, USA. margo@soest.hawaii.edu
Nature
|March 10, 2001
概括
在超慢传播的Gakkel山脊发现了火山活动,挑战了关于中洋山脊火山活动的先前假设. 这一发现表明,即使在传播速度最慢的情况下,也会发生集中,大量的喷发.
科学领域:
- 地质地质地质地质地质地
- 地质物理学 地质物理学
- 海洋学 海洋学 海洋学
背景情况:
- 海底在中洋山脊上扩散是由火山和构造过程驱动的.
- 火山活动的影响随着传播速度的下降而减弱,在极低的速度 (<1.5厘米/年) 时存在未知的活动.
研究的目的:
- 为了调查在超缓慢扩散的Gakkel山脊的火山活动的程度.
- 为了确定是否发生显著的火山活动,其速率低于1.5厘米/年.
主要方法:
- 通过核潜艇的船体安装声纳,获得了Gakkel山脊的三维声纳地图.
- 分析了来自东部Gakkel山脊的侧扫描声纳数据.
主要成果:
- 绘制了两个年轻的火山,覆盖约720平方公里,位于东部Gakkel山脊的轴谷.
- 确定了一个西部火山与远距离地震事件中心相吻合,这表明最近的轴性喷发.
- 在这个超慢扩散的山脊上观察到聚焦的,大量的和可能频繁的喷发.
结论:
- 显著的火山活动发生在超慢传播的中洋山脊上.
- 加克尔山脊的火山爆发是局部性的,并且比之前所认为的要大得多.
- 这项研究重塑了我们对极端海底扩散速度的火山过程的理解.
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