• ISSN 2097-1893
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“洞察”号能够完成火星内部结构探测的使命吗?

刘澜波

引用本文: 刘澜波. “洞察”号能够完成火星内部结构探测的使命吗? 地球与行星物理论评,2021,52(1):115-123
Liu L B. Will InSight be able to accomplish the task to image Mars interior? Reviews of Geophysics and Planetary Physics, 2021, 52(1):115-123

“洞察”号能够完成火星内部结构探测的使命吗?

doi: 10.19975/j.dqyxx.2020-015
详细信息
    通讯作者:

    刘澜波,男,教授,主要从事理论与应用地球物理研究。E-mail: lanboliu77@gmail.com

  • 中图分类号: O319.56

Will InSight be able to accomplish the task to image Mars interior?

  • 摘要: 本文聚焦于“洞察”号(InSight)的SEIS项目,介绍它的主要科研目标,以及已有的初步探测与解释成果. 作者试图就“洞察”号能在什么程度上实现对火星内部结构探测的科研目标作出评论. 评论从三个方面展开:即它能够基本回答的问题,部分回答的问题,及基本上不可能回答的问题. 基于到目前为止的观测事实,可以说SEIS的数据分析结果对“洞察”号着陆点附近的浅地表结构会有精细的描述;对火星壳层的局部结构会有相当的了解. 有可能会对火星上部幔层结构提供一些比以前更为严密的约束. 但是,到目前为止SEIS数据对人类加深对于火星核结构了解的贡献应该是相对有限的. 主要原因是缺乏能量足够大的震源来产生传播于整个火星的波动场.

     

  • 图  1  基于单台、多个单震数据反演火星结构的流程图(修改自Khan et al., 2016

    Figure  1.  Joint seismic event-location and structure-inversion scheme based on single station,multiple single-event (modified from Khan et al., 2016)

    图  2  经过半径归一化后的层状火星模型(修改自Brennan et al., 2020)(红色曲线)与层状地球模型(修改自Dziewonski and Anderson, 1981)(蓝色曲线). 点线为密度;实线为P波速度;断线为S波速度

    Figure  2.  The layered modelsof density (dotted line), P-wave velocity VP (solid line) and S-wave velocity Vs (broken line) for Mars (modified from Brennan et al., 2020) (red) and the Earth (modified from Dziewonski and Anderson, 1981) (blue)

    图  3  火星震P波与S波速度深度剖面模型切片图(修改自Brennan et al., 2020

    Figure  3.  The layered model of P-wave velocity VP and S-wave velocity VS of the Mars expressed as the cross-section through a great circle (modified from Brennan et al., 2020)

    图  4  由位于θ=180°的径向撞击源造成的3个时刻(1 000s,左列;10 000s,中列;20 000s,右列)的模拟波场(上行:体应变;下行:剪应变)在火星内部的分布. 波场色标各异,以突出波场特征

    Figure  4.  The synthetic wave field caused by the impact source at θ=180°. Volumetric strain: top row; shear strain: bottom row; t=1 000 s, left column, t=10 000 s, central column; t=20 000 s, right column. The color scales are varying for individual plot to highlight the tempo-spatial variation of the wave fields

    图  5  由位于θ=180°的垂直撞击源造成的在震中距为0°~180°内6个小时的合成记录图 (左列:表面压强P;中列:径向震动速度Vr;右列:环向震动速度Vθ

    Figure  5.  The 6-h synthetic seismogram caused by a vertical impact source at θ=180°; left: surface pressure P; middle: radial particle velocity Vr; right: tangential particle velocity Vθ

    图  6  位于撞击源对顶点(震中距Δ=180°)的合成记录图

    Figure  6.  The single station synthetic seismogram recorded at epicenter distance Δ=180°

    图  7  撞击源造成震波的频谱图

    Figure  7.  The spectra of synthetic records due to an impact

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出版历程
  • 收稿日期:  2020-09-01
  • 录用日期:  2020-09-21
  • 网络出版日期:  2021-09-13
  • 刊出日期:  2021-01-01

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