A New Hypothesis for Relative High Rate of Volcanism in the Hesperian on Mars

The rates of impact, weathering, erosion and valley formation on Mars all decreased greatly at the end of the Noachian. However, the average rate of volcanism stayed at a relatively high level throughout the Hesperian. The reason for extensive lava plains in the Hesperian is intriguing, since the rate of volcanism in the later time should have decreased dramatically than earlier time due to decreasing of internal thermal energy. Recent modeling results brought up 'cold and icy' against the prevalent 'warm and wet' for the early Mars, which showed tens to hundreds meters thick ice covered the Noachian highlands at a very limited total water inventory in 40 martian years. However, the thickness of ice could be much larger considering the enormous amount of water which created the channels and valleys on martian surface. In Iceland of Earth, both observation and numerical modeling results show that the great increase of rate of volcanism in the 1000-year time scale could be a result of ice sheet melting. Inspired from what has happened in Iceland, in this study, we are going to investigate the possibility of increasing the rates of volcanism by deglaciation in the Hesperian time. Our hypothesis is that the high rates of volcanism in Hesperian of Mars could also be the result of deglaciation.