EP53A-0975
Tsunami waves extensively resurfaced the shorelines of a receding, early Martian ocean
Friday, 18 December 2015
Poster Hall (Moscone South)
Alexis Palmero Rodriguez1, Alberto Fairen2,3, Rogelio Linares4, Mario Zarroca4, Thomas Platz5, Goro Komatsu6, Jeffrey S Kargel7, Virginia C Gulick8, Jianguo Yan9, Kana Higuchi3, Victor R Baker7 and Natalie Hanson Glines10, (1)Planetary Science Institute Tucson, Tucson, AZ, United States, (2)Cornell University, Ithaca, NY, United States, (3)Centro de Astrobiologia, Madrid, Spain, (4)Autonomous University of Barcelona, Cerdanyola del Val, Spain, (5)Max Planck Institute for Solar System Research, Katlenburg-Lindau, Germany, (6)University of Chieti-Pescara, Pescara, Italy, (7)University of Arizona, Tucson, AZ, United States, (8)NASA Ames Research Center, Moffett Field, CA, United States, (9)Wuhan University, Wuhan, China, (10)Self Employed, Washington, DC, United States
Abstract:
It has been proposed that ~3.5 billion years ago an enormous ocean fed by catastrophic groundwater discharges covered most of the Martian northern plains. However, a persistent problem with this hypothesis is the lack of definitive paleoshoreline features. Here, based on geomorphic and thermal surface character mapping and numerical analysis in the circum-Chryse region of the northern plains, 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 tsunami events produced widespread, extant littoral landforms, including run-up sedimentary lobes hundreds of kilometers long across gently sloping plains and backwash channels where wave retreat occurred on highland boundary surfaces. Variations among the features associated with each tsunami event suggest that the ocean was relatively more frozen during the second event.
