地球宜居性的深部驱动机制

Earth’s habitability driven by deep processes

除与太阳之间的距离和行星的大小有关外,地球之所以宜居的一个重要因素是其拥有动力十足的地球内部.与地球宜居性是地球表生作用结果的传统认识不同,本文认为地球深部驱动着对宜居环境至关重要的外部层圈,并提出地球内外层圈间的联动机制是地球系统科学研究的突破口.在调研和评述的基础上,本文建议未来研究需要关注早期地球、地磁场、深地挥发分循环、超级火山、深地新化学反应和地质空调器等方向,围绕地球宜居性的深部驱动机制这一主题,开展地球固体层圈与流体层圈的整合研究,助力我国地球科学研究从单一学科研究向多学科交叉融合研究的转变,推动我国固体地球科学从跟踪前沿向开拓前沿的跨越式发展.

Earth is the only habitable planet in the solar system with life.The Earth has two major characteristics that distinct itself from all the inhabitable planets:One is that it has an active interior,and the other is that it has plate tectonics,where the former is a prerequisite for the latter.The energy related to the convection,cooling and exothermic processes of the core and mantle is about 34−66 TW,which supports the operation of the entire plate tectonic system.Once the energy inside the Earth is exhausted,the plate tectonics will cease accordingly.From the perspective of material composition,more than 90%of elements such as carbon,hydrogen,and oxygen that have a decisive impact on the habitable environment on the surface are essentially stored in the deep Earth.Therefore,a slight“turbulence”in the deep Earth will profoundly affect the Earth’s surface system,resulting in deformation and metamorphism,resource enrichment,and dramatic changes in climate and environment on the geological time scale.The dynamism of Earth’s interior not only directly leads to the development of deep megastructures such as the large low shear velocity provinces of the core-mantle boundary and the core engine,but also gives rise to a series of major events in geological history as the primary driving force,such as the growth of continental crust,the initiation of plate tectonics,continental aggregation and breakup,Great Oxidation Event,Snowball Earth,large igneous provinces,life explosions,and mass extinctions.Therefore,the deep Earth is the operation engine of the entire Earth system.Only by grasping this crucial Earth’s engine and unraveling the linking mechanism between internal spheres and exospheres of the Earth represents can we effectively reveal the nature of the interaction of different layers in the Earth system and promote the development of Earth system science.This paper suggests following research themes in future:Early Earth,geomagnetic field,volatile cycling,supervolcanoes,new chemical reaction in deep interior and geo-air conditioning.