Topography Profile Diagrams of Mars: a Step toward the Formal Proof of Martian Ocean Recession, Timing and Probability

Introduction: After the initial proposal of Contact 1 and 2 [1], previously published papers about ocean on Mars can basically be divided in two groups. The first one was based on shorelines theory, however, shorelines were unfortunately not found in required amount. Papers from the second group, discussing basically whether Contact 1 or 2 is better approach, proposed as indicators for ocean on Mars: spiral beaches [2], sedimentation [3], hydraulic and thermal arguments [4], impact craters [5], fluvial valleys [6], tsunami generation and propagation [7], erosion features that might be ancient coastal terraces [8], etc. Recently, mathematical approach was proposed [9] providing a way to compute how deep Martian ocean was during each period of the planet history, including the probability that ocean did exist once. In Fig. 1 and Fig. 2 we have level of ocean for time when 65% and 85% of impact craters was already created [9], and in Fig. 3 Contact 1 and 2 [10]. It is interesting to find out that according to those proposed computations [9], as shown in Fig. 4, both Contacts are good approximations, each one for some particular period of the planet history. This also explains why shorelines were not found in supposed amount, ocean that is constantly drying up can not leave some significant shorelines at a particular level.