| Deltas, fans and channels on Mars clearly indicate surface water in the past. These features contain valuable information about the duration and magnitude of surface water, with obvious implications for potential life on Mars. Martian deltas show architectural elements similar to terrestrial deltas, e.g. delta lobes, terraces in incised valleys, convex/concave delta-plain gradients, and incised delta fronts. Our pilot experiments demonstrate that delta morphology is related to flow discharge and duration, sediment properties and crater size. However, these important relationships between morphology and climate remain unquantified. Our proposal uses the unique remote sensing data by Mars Express-HRSC to quantify these relations. Our objectives are to quantify the architectural elements of martian delta systems and systematically explore their relations with formative conditions in flume experiments, to provide novel constraints on climatic conditions of early Mars. In particular we focus on how much water was released and whether the flow was episodic (possibly related to volcanic activity and ice melting) or sustained (possibly related to a global climate change). First, we quantify key architectural elements of deltas on Mars using images and high-resolution Digital Elevation Maps (DEMs). Then we establish experimentally how these morphologies emerge in the 'Eurotank', a large laboratory basin equipped with photogrammetry producing high-quality DEMs for quantitative comparison to martian DEMs. We verify the results against terrestrial systems and the scaling between experiment and large-scale systems is addressed using verified models correcting for gravity. We believe this work will provide novel insights in martian and terrestrial palaeo-climates. |
