Long-term drying of Mars by sequestration of ocean-scale volumes of water in the crust

Geological evidence shows that ancient Mars had large volumes of liquid water. Models of past hydrogen escape to space, calibrated with observations of the current escape rate, cannot explain the present-day deuterium-to-hydrogen isotope ratio (D/H). We simulated volcanic degassing, atmospheric esca...

Full description

Saved in:
Bibliographic Details
Published in:Science (American Association for the Advancement of Science) 2021-04, Vol.372 (6537), p.56-62
Main Authors: Scheller, E L, Ehlmann, B L, Hu, Renyu, Adams, D J, Yung, Y L
Format: Article
Language:English
Subjects:
Aridity
Atmospheric models
Degassing
Deuterium
Drying
Hydration
Hydrogen
Hydrogen isotopes
Hydrologic cycle
Hydrology
Ice caps
Isotope ratios
Mars
Mars surface
Mars volcanoes
Minerals
Oceans
Planetary geology
SNC meteorites
Spacecraft
Terrestrial environments
Terrestrial planets
Water
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Geological evidence shows that ancient Mars had large volumes of liquid water. Models of past hydrogen escape to space, calibrated with observations of the current escape rate, cannot explain the present-day deuterium-to-hydrogen isotope ratio (D/H). We simulated volcanic degassing, atmospheric escape, and crustal hydration on Mars, incorporating observational constraints from spacecraft, rovers, and meteorites. We found that ancient water volumes equivalent to a 100 to 1500 meter global layer are simultaneously compatible with the geological evidence, loss rate estimates, and D/H measurements. In our model, the volume of water participating in the hydrological cycle decreased by 40 to 95% over the Noachian period (~3.7 billion to 4.1 billion years ago), reaching present-day values by ~3.0 billion years ago. Between 30 and 99% of martian water was sequestered through crustal hydration, demonstrating that irreversible chemical weathering can increase the aridity of terrestrial planets.
ISSN:0036-8075
1095-9203
DOI:10.1126/science.abc7717