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Sanna Alwmark

Sanna Alwmark

Postdoctoral fellow

Sanna Alwmark

Perseverance rover reveals an ancient delta-lake system and flood deposits at Jezero crater, Mars


  • N. Mangold
  • S. Gupta
  • O. Gasnault
  • G. Dromart
  • J. D. Tarnas
  • S. F. Sholes
  • B. Horgan
  • C. Quantin-Nataf
  • A. J. Brown
  • S. Le Mouélic
  • R. A. Yingst
  • J. F. Bell
  • O. Beyssac
  • T. Bosak
  • F. Calef
  • B. L. Ehlmann
  • K. A. Farley
  • J. P. Grotzinger
  • K. Hickman-Lewis
  • S. Holm-Alwmark
  • L. C. Kah
  • J. Martinez-Frias
  • S. M. McLennan
  • S. Maurice
  • J. I. Nuñez
  • A. M. Ollila
  • P. Pilleri
  • J. W. Rice
  • M. Rice
  • J. I. Simon
  • D. L. Shuster
  • K. M. Stack
  • V. Z. Sun
  • A. H. Treiman
  • B. P. Weiss
  • R. C. Wiens
  • A. J. Williams
  • N. R. Williams
  • K. H. Williford

Summary, in English

Observations from orbital spacecraft have shown that Jezero crater on Mars contains a prominent fan-shaped body of sedimentary rock deposited at its western margin. The Perseverance rover landed in Jezero crater in February 2021. We analyze images taken by the rover in the 3 months after landing. The fan has outcrop faces, which were invisible from orbit, that record the hydrological evolution of Jezero crater. We interpret the presence of inclined strata in these outcrops as evidence of deltas that advanced into a lake. In contrast, the uppermost fan strata are composed of boulder conglomerates, which imply deposition by episodic high-energy floods. This sedimentary succession indicates a transition from sustained hydrologic activity in a persistent lake environment to highly energetic short-duration fluvial flows.


  • Lithosphere and Biosphere Science

Publishing year










Document type

Journal article


American Association for the Advancement of Science (AAAS)


  • Aerospace Engineering




  • ISSN: 0036-8075