EGU2020-5824, updated on 10 Jun 2023
https://doi.org/10.5194/egusphere-egu2020-5824
EGU General Assembly 2020
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

Tsunami on Mars: Implications for the duration and timing of a northern ocean

Francois Costard1, José Alexis Palmero Rodriguez2, Antoine Séjourné1, Anthony Lagain1,3, Steve Clifford2, Jens Ormö4, Sylvain Bouley1, Karim Kelfoun5, and Franck Lavigne6
Francois Costard et al.
  • 1UMR 8148 GEOPS, CNRS/Université Paris Saclay, Orsay, France (francois.costard@u-psud.fr)
  • 2Planetary Science Institute, Tucson, Arizona, USA
  • 3School of Earth and Planetary Science, Curtin University, GPO Box U1987, Perth, WA, 6845, Australia
  • 4Centro de Astrobiología INTA-CSIC, Instituto Nacional de Técnica Aeroespacial, Spain
  • 5Laboratoire Magmas et Volcans, OPGC, UBP-IRD-CNRS, Aubière, France
  • 6Université Paris 1, Panthéon-Sorbonne, Laboratoire de Géographie Physique, UMR 8591 Meudon, France

The duration and timing of a northern ocean is a key issue in understanding the past geological and climatic evolution of Mars. Mars experienced its greatest loss of H2O between the Noachian and Late Hesperian (~10 m Global Equivalent Layer, Jakosky et al., 2017) roughly the same amount that is thought to have been added to the global inventory by extrusive volcanism over the same time period (Carr and Head, 2015). Thus, the total inventory of water was probably similar during these two epochs. But, the ocean during the Late Hesperian was smaller in extension than the ocean during the Noachian– with significant implications for the potential origin and survival of life. Here we examine the implications of the existence of a Late Hesperian/ Early Amazonian ocean on the planet’s inventory of water (and especially liquid water) and its variation with time. Our previous work (Rodriguez et al., 2016; Costard et al., 2017) concluded that the most plausible explanation for the origin of the Thumbprint Terrain (TT) lobate deposits, with run-ups, found along the dichotomy boundary, especially in Arabia Terra, was tsunami deposits. This supports the hypothesis that an ocean occupied the northern plains of Mars as recently as ~3 billion years ago. Furthermore, Costard et al (2017) produced a tsunami numerical model showing that the TT deposits exhibit fine-scale textural patterns due to the wave’s interference patterns resulting from interactions with the coastal topography. More recently, we suggested that the unusual characteristics of Lomonosov crater (50.52°N/16.39°E ) in the northern plains are best explained by the presence of a shallow ocean at the time of the impact (Costard et al., 2019). Interestingly, the apparent agreement between the age of the Lomonosov impact and that of the TT unit (~3 Ga), strongly suggests that it was the source of the tsunami (Costard et al., 2019). Our preliminary assessment indicates that this impact-generated tsunami required a mostly liquid ocean and because of the high latitude location of the Lomonosov crater site, our results strongly imply relatively warm paleoclimatic conditions. Our conclusions highlight the need for more sophisticated climate models.

How to cite: Costard, F., Rodriguez, J. A. P., Séjourné, A., Lagain, A., Clifford, S., Ormö, J., Bouley, S., Kelfoun, K., and Lavigne, F.: Tsunami on Mars: Implications for the duration and timing of a northern ocean, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-5824, https://doi.org/10.5194/egusphere-egu2020-5824, 2020.