Kite Edwin S, Mayer David P, Wilson Sharon A, Davis Joel M, Lucas Antoine S, Stucky de Quay Gaia
University of Chicago, Chicago, IL, USA.
Center for Earth and Planetary Studies, Smithsonian Institution, Washington, DC, USA.
Sci Adv. 2019 Mar 27;5(3):eaav7710. doi: 10.1126/sciadv.aav7710. eCollection 2019 Mar.
Mars is dry today, but numerous precipitation-fed paleo-rivers are found across the planet's surface. These rivers' existence is a challenge to models of planetary climate evolution. We report results indicating that, for a given catchment area, rivers on Mars were wider than rivers on Earth today. We use the scale (width and wavelength) of Mars paleo-rivers as a proxy for past runoff production. Using multiple methods, we infer that intense runoff production of >(3-20) kg/m per day persisted until <3 billion years (Ga) ago and probably <1 Ga ago, and was globally distributed. Therefore, the intense runoff production inferred from the results of the Mars Science Laboratory rover was not a short-lived or local anomaly. Rather, precipitation-fed runoff production was globally distributed, was intense, and persisted intermittently over >1 Ga. Our improved history of Mars' river runoff places new constraints on the unknown mechanism that caused wet climates on Mars.
如今的火星十分干燥，但在其地表发现了众多由降水形成的古河流。这些河流的存在对行星气候演化模型构成了挑战。我们报告的结果表明，在给定集水面积的情况下，火星上的河流比如今地球上的河流更宽。我们将火星古河流的规模（宽度和波长）用作过去径流产生量的指标。通过多种方法，我们推断出每天大于（3 - 20）千克/米的强烈径流产生一直持续到不到30亿年前，可能还不到10亿年前，且分布于全球。因此，从火星科学实验室探测器的结果推断出的强烈径流产生并非短暂的局部异常现象。相反，由降水形成的径流产生在全球范围内分布广泛、强度较大，并且间歇性地持续了超过10亿年。我们对火星河流径流历史的改进对导致火星湿润气候的未知机制提出了新的限制。
