DOI: 10.6084/m9.figshare.14077229
title: Data supporting the conclusions in Rosebourough et al. (2021)

description: Data files and descriptions contained here:<br>1. model_outputs: Hydrologic model output as shapefiles. Model described in detail in Horvath et al. (2016) and adapted for Mars in Horvath & Andrews‐Hanna (2017). This numerical model is a combined surface-subsurface hydrology model, with input evaporation potential (<i>E<sub>p</sub></i>) and precipitation (<i>P</i>) rates from Earth analog climates provided by the North American Land Data Assimilation Systems Phase-2 observation-based climate model. An annual precipitation of 300 mm/Mars year was assumed, uniformly distributed across the model domain. The total annual precipitation reaching either the surface or subsurface hydrologic system was determined using an Earth-based empirical method dependent on the aridity index (<i>φ</i>=<i>E<sub>p</sub></i>/<i>P</i>; Budyko, 1974). This approach relates the aridity index (<i>φ)</i> to the measured catchment discharge, deriving an estimate of the actual evaporative loss from the catchment. Subsurface flow was modeled using a finite-difference approximation to the groundwater flow equation, controlled by a depth dependent permeability (depth averaged permeability of 1 10<sup>-13</sup> m<sup>2</sup>) and porosity (20%) distribution, and an assumed aquifer depth (10 km) based on the megaregolith aquifer model of Hanna and Phillips (2005). Runoff was modeled using a simple linear reservoir approximation which assumes catchment storage is linearly related to runoff. Lakes were allowed to naturally form on the surface where the contribution of groundwater, surface water, and precipitation directly to the lake balanced evaporation off of the lake surface. We focused on the aridity index dependence for modeled lake areas and elevations - here we provide model outputs with aridity indices of 1.5 (subhumid) and 3.5 (semiarid) (the two main climate conditions we focused on in the main paper).<br>2. shapefiles.zip: For morphologic analysis, mapping was performed on an orthorectified and equalized basemap constructed from 6 m/pixel resolution Context Camera (CTX) imagery (Malin et al., 2007). For each crater within our region, we mapped all observed gully networks (GN) around the interior crater rim (at approximately 1:150,000 scale), which are small-scale branching erosional features. At the termination of each GN, we recorded the elevation using High-Resolution Stereo Camera (HRSC) digital elevation models (DEMs) where available (~10–30 m vertical resolution) (Jaumann et al., 2007), and the global 463 m/pixel resolution Mars Orbiter Laser Altimeter (MOLA; Smith et al., 2001) dataset otherwise (at ~100 m vertical resolution). We selected and mapped eighteen craters, six of which were previously identified as inferred paleolakes (Fassett & Head, 2008; Goudge et al., 2015; Grotzinger et al., 2014, 2015) .<br>3. Roseborough_GRL_CraterCountData_SI_Resubmission_v0: We used the CraterTools ArcMap add-in to map crater ejecta and floors within the Gale crater region at approximately 1:100,000 scale, allowing us to capture craters at and below the 1 km diameter minimum benchmark (Kneissl et al., 2011). Crater diameters were then exported from ArcGIS. Here we report the surface area and the corresponding crater diameters for each surface we mapped (and include the crater stats figures (showing the derived modeled age) and our crater maps).