火星上最近和偶尔的火山和冰川活动是由高分辨率立体相机揭示的
G Neukum1, R Jaumann, H Hoffmann
1Institut fuer Geologische Wissenschaften, Freie Universitaet Berlin, Malteserstrasse 74-100, Bldg D, 12249 Berlin, Germany. gneukum@zedat.fu-berlin.de
Nature
|December 24, 2004
概括
火星的火山显示最近的活动,其中一些可能今天仍然活跃. 有证据表明,火山复苏和冰川活动最近发生在200万年前.
科学领域:
- 行星科学 行星科学
- 火山学 火山学是一门学科.
- 冰川学的冰川学
背景情况:
- 欧洲航天局的火星快速任务上的高分辨率立体相机实验 (HRSC) 提供了火星的高分辨率3D图像.
- 以前的研究已经提供了对火星地质演变的见解,但对火山和冰川特征的详细时间战略分析是有限的.
研究的目的:
- 为了调查最近的地质活动和主要火星火山的演变.
- 为了分析火星上的火山和冰川结构之间的时间战略学关系.
- 评估正在进行的火山活动的潜力和火星火山上水冰的存在.
主要方法:
- 利用了来自Mars Express高分辨率立体相机实验的高分辨率 (10-20 m/pixel) 彩色和3D数据.
- 分析了五个主要火星火山上的火山和冰川沉积物的形态证据.
- 根据地平面关系和估计的年龄来确定地质事件的日期.
主要成果:
- 五个主要火星火山上的火山口在火星历史上过去20%的时间里反复激活和重新浮出水面,其中一些活动最早发生在200万年前.
- 奥林匹斯山 (Olympus Mons) 底部的冰川沉积物显示出重复活动的证据,直到大约400万年前.
- 形态学证据表明,在奥林匹斯山7000米以上的海拔上,雪和冰沉积,导致冰川事件. 水冰可能仍然存在于高海拔地区,受到尘埃的保护.
结论:
- 火星火山表现出潜在的持续活动,挑战了关于它们休眠状态的先前假设.
- 火星最近的冰川活动,特别是在奥林巴斯山,突出了相对最近发生的气候和地质过程的动态.
- 这些发现表明,有利于保存水冰的条件可能仍然存在于高海拔的火星火山结构上.
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