title: Tsunami waves extensively resurfaced the shorelines of an early Martian ocean.
abstract: It has been proposed that ~3.4 billion years ago an ocean fed by enormous catastrophic floods covered most of the Martian northern lowlands. However, a persistent problem with this hypothesis is the lack of definitive paleoshoreline features. Here, based on geomorphic and thermal image mapping in the circum-Chryse and northwestern Arabia Terra regions of the northern plains, in combination with numerical analyses, we show evidence for two enormous tsunami events possibly triggered by bolide impacts, resulting in craters ~30 km in diameter and occurring perhaps a few million years apart. The tsunamis produced widespread littoral landforms, including run-up water-ice-rich and bouldery lobes, which extended tens to hundreds of kilometers over gently sloping plains and boundary cratered highlands, as well as backwash channels where wave retreat occurred on highland-boundary surfaces. The ice-rich lobes formed in association with the younger tsunami, showing that their emplacement took place following a transition into a colder global climatic regime that occurred after the older tsunami event. We conclude that, on early Mars, tsunamis played a major role in generating and resurfacing coastal terrains.
authors.affiliation: Planetary Science Institute, 1700 East Fort Lowell Road, Suite 106, Tucson, AZ 85719-2395, USA.|NASA Ames Research Center, Mail Stop 239-20, Moffett Field, CA, 94035, USA.
authors.forename: J Alexis P
authors.initials: JA
authors.lastname: Rodriguez
authors.affiliation: Department of Planetology and Habitability, Centro de Astrobiología (CSIC-INTA), Madrid 28850, Spain.|Department of Astronomy, Cornell University, Ithaca, NY 14850, USA.
authors.forename: Alberto G
authors.initials: AG
authors.lastname: Fairén
authors.affiliation: Astrogeology Science Center, U.S. Geological Survey, Flagstaff, AZ 86001, USA.
authors.forename: Kenneth L
authors.initials: KL
authors.lastname: Tanaka
authors.affiliation: External Geodynamics and Hydrogeology Group, Department of Geology, Autonomous University of Barcelona, 08193 Bellaterra, Barcelona, Spain.
authors.forename: Mario
authors.initials: M
authors.lastname: Zarroca
authors.affiliation: External Geodynamics and Hydrogeology Group, Department of Geology, Autonomous University of Barcelona, 08193 Bellaterra, Barcelona, Spain.
authors.forename: Rogelio
authors.initials: R
authors.lastname: Linares
authors.affiliation: Planetary Science Institute, 1700 East Fort Lowell Road, Suite 106, Tucson, AZ 85719-2395, USA.|Planetary Sciences and Remote Sensing, Institute of Geological Sciences, Freie Universität Berlin, 12249 Berlin, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Platz
authors.affiliation: International Research School of Planetary Sciences, Università d'Annunzio, Viale Pindaro 42, 65127 Pescara, Italy.
authors.forename: Goro
authors.initials: G
authors.lastname: Komatsu
authors.affiliation: The University Museum, University of Tokyo, 113-0033, Japan.
authors.forename: Hideaki
authors.initials: H
authors.lastname: Miyamoto
authors.affiliation: Department of Hydrology &Water Resources, University of Arizona, Tucson, AZ 85721, USA.
authors.forename: Jeffrey S
authors.initials: JS
authors.lastname: Kargel
authors.affiliation: State Key Laboratory of Information Engineering in Surveying, Mapping and Remote Sensing, Wuhan University, Wuhan 430070, China.
authors.forename: Jianguo
authors.initials: J
authors.lastname: Yan
authors.affiliation: NASA Ames Research Center, Mail Stop 239-20, Moffett Field, CA, 94035, USA.|SETI Institute, 189 Bernardo Avenue, Mountain View, CA 94043, USA.
authors.forename: Virginia
authors.initials: V
authors.lastname: Gulick
authors.affiliation: Department of Planetology and Habitability, Centro de Astrobiología (CSIC-INTA), Madrid 28850, Spain.
authors.forename: Kana
authors.initials: K
authors.lastname: Higuchi
authors.affiliation: Department of Hydrology &Water Resources, University of Arizona, Tucson, AZ 85721, USA.
authors.forename: Victor R
authors.initials: VR
authors.lastname: Baker
authors.affiliation: NASA Ames Research Center, Mail Stop 239-20, Moffett Field, CA, 94035, USA.|SETI Institute, 189 Bernardo Avenue, Mountain View, CA 94043, USA.
authors.forename: Natalie
authors.initials: N
authors.lastname: Glines
mesh_terms: D003081:Cold Climate; D055868:Floods; D018535:Mars; D009792:Oceans and Seas; D057192:Tsunamis