Research press release


Nature Geoscience

Cold early Mars warmed in bursts by volcanism


Itay HalevyとJames Headは計算機モデリングにより、大規模な火山噴火による硫黄の放出が、どのように火星初期の気候に影響を及ぼしたかを調べた。シミュレーションでは、温室効果ガスである二酸化硫黄の放出と、塵を含んだ大気中で硫黄に被覆されたエアロゾル粒子が形成されることが火星表面の全体の加熱効果をもたらしている。研究者等は、火山活動が一時的に低緯度地方で日最高気温を氷点以上に増加させ、この条件が数十年から数百年の期間にわたり継続し得たと示唆している。


The surface of early Mars may have been repeatedly warmed by episodes of intense volcanic activity, according to a study published online in Nature Geoscience. Evidence that liquid water once flowed on the Martian surface has previously been difficult to reconcile with predictions of a cold climate on early Mars.

Itay Halevy and James Head used computer modelling to investigate how sulphur emissions from large volcanic eruptions may have influenced the early Martian climate. In the simulations, emissions of the greenhouse gas sulphur dioxide and the formation of sulphate-coated aerosol particles in a dusty atmosphere led to a net warming effect at the Martian surface. The researchers suggest that volcanism could have temporarily increased the maximum daily temperatures above freezing in low latitude regions and that these conditions could have persisted for periods of tens to hundreds of years.

Intermittent surface melting triggered by volcanism is consistent with previous evidence that the channels and valley networks on ancient Martian terrains were formed during transient wet episodes.

doi: 10.1038/ngeo2293


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