title: Earth-like aqueous debris-flow activity on Mars at high orbital obliquity in the last million years.
abstract: Liquid water is currently extremely rare on Mars, but was more abundant during periods of high obliquity in the last few millions of years. This is testified by the widespread occurrence of mid-latitude gullies: small catchment-fan systems. However, there are no direct estimates of the amount and frequency of liquid water generation during these periods. Here we determine debris-flow size, frequency and associated water volumes in Istok crater, and show that debris flows occurred at Earth-like frequencies during high-obliquity periods in the last million years on Mars. Results further imply that local accumulations of snow/ice within gullies were much more voluminous than currently predicted; melting must have yielded centimetres of liquid water in catchments; and recent aqueous activity in some mid-latitude craters was much more frequent than previously anticipated.
authors.affiliation: Faculty of Geosciences, Universiteit Utrecht, Heidelberglaan 2, 3584 CS, Utrecht, The Netherlands.
authors.forename: T
authors.initials: T
authors.lastname: de Haas
authors.affiliation: Institute of Planetary Research, German Aerospace Center, Rutherfordstrasse 2, Berlin DE-12489, Germany.
authors.forename: E
authors.identifier: 000000021375304X
authors.initials: E
authors.lastname: Hauber
authors.affiliation: Department of Physical Sciences, Open University, Walton Hall, Milton Keynes MK7 6AA, UK.
authors.forename: S J
authors.initials: SJ
authors.lastname: Conway
authors.affiliation: Faculty of Geosciences, Universiteit Utrecht, Heidelberglaan 2, 3584 CS, Utrecht, The Netherlands.
authors.forename: H
authors.initials: H
authors.lastname: van Steijn
authors.affiliation: Department of Earth Sciences, University of Gothenburg, Gothenburg SE-405 30, Sweden.
authors.forename: A
authors.initials: A
authors.lastname: Johnsson
authors.affiliation: Faculty of Geosciences, Universiteit Utrecht, Heidelberglaan 2, 3584 CS, Utrecht, The Netherlands.
authors.forename: M G
authors.initials: MG
authors.lastname: Kleinhans