Morphometric Analysis of the 2004 Banda Aceh Tsunami Deposits as Analogs for Martian Paleotsunami Features

In the eastern part of the Arabia Terra cratered boundary, lobate deposits are observed on top of north-sloping highland mesas. Our previous studies (Rodriguez et al., 2016; Costard et al., 2017) suggest that the most plausible origin for these lobate morphologies are tsunami deposits associated with the Lomonosov impact event in an Hesperian age ocean (Costard et al., 2019). Tsunami deposits on Earth serve as valuable analogs for interpreting possible tsunami-related features on Mars, especially regarding hypothesized ancient oceans. In this study, we examine the 2004 Banda Aceh tsunami terrain in Indonesia (Lavigne et al., 2009) as an analog site to refine our understanding of Martian paleotsunami processes. We employ Volcflow (Kelfoun and Druitt, 2005), a numerical flow simulation tool, along with field-based and satellite observations to analyze tsunami inundation, run-up, and backwash dynamics. Satellite imagery (Lavigne et al., 2009) of the Banda Aceh region reveals sandy lobate deposits with distal ridges, contrasting with fine-grained, smooth deposits extending farther inland. These depositional and erosional features closely resemble potential tsunami-related signatures observed on Mars, including lobate margins, distinctive surface textures, and backwash channels. The backwash channels at both sites display consistent width-to-depth ratios, parallel to sub-parallel orientation, and cross-sectional geometries, providing quantitative support for our interpretation of Martian paleoshorelines.