Europlanet Science Congress 2020
Virtual meeting
21 September – 9 October 2020
Europlanet Science Congress 2020
Virtual meeting
21 September – 9 October 2020
EPSC Abstracts
Vol.14, EPSC2020-58, 2020
https://doi.org/10.5194/epsc2020-58
Europlanet Science Congress 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

The Role of Lithology in Silicate Weathering and CO2 Regulation on Rocky Exoplanets

Kaustubh Hakim1, Dan J. Bower1, Meng Tian1, Russell Deitrick1, Pierre Auclair-Desrotour1, Daniel Kitzmann1, Caroline Dorn2, Klaus Mezger3, and Kevin Heng1
Kaustubh Hakim et al.
  • 1University of Bern, Center for Space and Habitability, Center for Space and Habitability, Bern, Switzerland (kaustubh.hakim@csh.unibe.ch)
  • 2University of Zurich, Institute of Computational Sciences, Winterthurerstrasse 190, 8057, Zurich, Switzerland
  • 3University of Bern, Institute of Geology, Baltzerstrasse 1+3, 3012 Bern, Switzerland

In the decade of JWST, ELT, TMT, PLATO, ARIEL and other specialized telescopes, observations of carbon dioxide in terrestrial exoplanet atmospheres are possible. The amount of carbon dioxide in the atmosphere of a tectonically active planet such as Earth is regulated by the carbonate-silicate cycle (long-term carbon cycle). Silicate weathering provides essential negative feedback to maintain temperate climates on Earth over billions of years. In this study, we model the chemistry of rock-water interaction for different silicate rocks and minerals applicable to both continental and seafloor weathering. We find that weathering rates depend mainly on the partial pressure of carbon dioxide, surface temperature and lithology, and other factors are secondary. This approach allows possessing a theoretical method to determine both continental and seafloor weathering rates on temperate exoplanets that depend little on present-day Earth calibrations. Our study gives a strong control over the connection between atmospheric observables and the carbon cycle. The ultimate goal is to provide an abiotic library of geological false positives of biosignatures.

How to cite: Hakim, K., Bower, D. J., Tian, M., Deitrick, R., Auclair-Desrotour, P., Kitzmann, D., Dorn, C., Mezger, K., and Heng, K.: The Role of Lithology in Silicate Weathering and CO2 Regulation on Rocky Exoplanets, Europlanet Science Congress 2020, online, 21 September–9 Oct 2020, EPSC2020-58, https://doi.org/10.5194/epsc2020-58, 2020