Turning Earth Into Venus: A Stochastic Model of Possible Evolutions of Terrestrial Topography

By Keith Cowing
Press Release
December 12, 2023
Filed under , ,
Turning Earth Into Venus: A Stochastic Model of Possible Evolutions of Terrestrial Topography
The power spectra of the uniform weighting map shown in the central row of Figure 3. The shaded regions around the evolved Earth spectra represent the 1Οƒ ranges of a set of 100 randomized simulations. The dashed lines highlight that, under the constraints of this model and its assumptions, the transformation of the surface consists of two essentially distinct steps: the smoothing of the continent/ocean bimodality via diffusion (shown by the red dashed lines), and the subsequent build-up of surface features through volcanic outflows (in green). This result implies that, while our model nominally assumes a constant surface diffusion rate and a fixed period of volcanism, the results will be virtually identical for equal values of the total diffusion (parametrized by βˆ† in Table 1) and total volcanic outflow mass. — astro-ph.EP

Venus may have had both an Earth-like climate as well as extensive water oceans and active (or incipient) plate tectonics for an extended interval of its history. The topographical power spectrum of Venus provides important clues to the planet’s past evolution.

By drawing detailed contrast with the strong low-order odd-l dominated global topography of Earth, we demonstrate that the relatively flat Venusian topography can be interpreted to have arisen from the transition from active terrestrial-like plate tectonics to the current stagnant lid configuration at a time Ο„=544+886βˆ’193 million years before present.

This scenario is plausible if loss of oceans and the attendant transition to a CO2-dominated atmosphere were accompanied by rapid continental-scale erosion, followed by gradual lava resurfacing at an outflow rate ∼ 1 km3 yrβˆ’1.

We study Venus’ proposed topographical relaxation with a global diffusion-like model that adopts terrestrial erosion rates scaled to account for the increased rainfall and temperatures that would accompany a planet-wide transition from an Earth-like climate to the runaway greenhouse climate that could ultimately yield present-day Venus, with an estimate of 5.1+1.8βˆ’1.1 Myr if the global erosion operated as efficiently as that of a typical bedrock river basin on Earth.

Arthur D. Adams (1), Greg Laughlin (2) ((1) University of California, Riverside, (2) Yale University)

Comments: 17 pages, 4 figures, submitted to AAS Journals
Subjects: Earth and Planetary Astrophysics (astro-ph.EP)
Cite as: arXiv:2312.07483 [astro-ph.EP] (or arXiv:2312.07483v1 [astro-ph.EP] for this version)
Submission history
From: Arthur Adams
[v1] Tue, 12 Dec 2023 18:14:20 UTC (2,359 KB)

Astrobiology, Terraforming,

Explorers Club Fellow, ex-NASA Space Station Payload manager/space biologist, Away Teams, Journalist, Lapsed climber, Synaesthete, Na’Vi-Jedi-Freman-Buddhist-mix, ASL, Devon Island and Everest Base Camp veteran, (he/him) πŸ––πŸ»