在极速缓慢扩散的Gakkel山脊,北冰洋的爆炸性火山活动
Robert A Sohn1, Claire Willis, Susan Humphris
1Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, USA. rsohn@whoi.edu
Nature
|June 27, 2008
概括
爆炸性火山喷发,以前认为不可能的深海,已经在Gakkel山脊发现. 在4000米深处发现了超过10平方公里的火态沉积物,挑战了关于岩碎片化的先前假设.
科学领域:
- 地质地质地质地质地质地
- 火山学 火山学是一门学科.
- 海洋学 海洋学 海洋学
背景情况:
- 大洋地覆盖了地球表面的60%,是由中洋山脊火山活动形成的.
- 爆炸性喷发在3000米以下被认为是罕见的,这是由于高水静压和低岩挥发性物质含量.
研究的目的:
- 通过使用先进的深度潜水技术,研究扩散超缓的Gakkel山脊的火山地形.
- 为了记录火山活动的证据,在海水临界点以下的深度.
主要方法:
- 利用新的深度潜水技术对Gakkel山脊进行摄影和视频成像.
- 在北极盆地大约4000米水深的"零年龄"火山地形进行了调查.
主要成果:
- 发现了广泛的未巩固的火岩沉积物,包括泡墙碎片,覆盖了轴谷10平方公里以上.
- 在这些深度确定了至少13.5%的二氧化碳的必要性,以使岩碎片化,远高于以前测量的值.
结论:
- 在中洋山脊火山系统的最深处,大规模的火山弹性活动是可能的.
- 这些发现挑战了长期以来的信念,即在3000米以下的深度不存在爆炸性火山活动.
- 提出了关于挥发性积累和排放机制在超慢扩散的山脊的问题.
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