Thrust Faulting and the Late-stage Contraction of the Moon
4 affiliations
- 1Smithsonian Institution
- 2NASA Goddard Space Flight Center
- 3University of Maryland
- 4Intuitive Machines
Abstract
Lunar Reconnaissance Orbiter Camera images have revealed thousands of young thrust fault scarps in the highlands and mare. These relatively small-scale faults are the expression of a period of late-stage lunar global contraction. Here we present the most comprehensive assessment of recent thrust faulting on the Moon and its implications for lunar radius change. Combining the estimate of the fractional areal strain of the highlands from the population of lobate thrust fault scarps with the fractional areal strain of the maria from the population of small mare ridge thrust faults, the total areal contractional strain is estimated to be ∼0.0048% to 0.0053%. This areal strain corresponds to a radial contraction of ∼42 to 46 m. Assuming a uniform rate of radius change over the last 400 Ma, the rate of change is estimated to be a maximum of ∼11 cm Ma ⁻¹ . The fractional areal strain of the maria contributes little to the total radius change, thus the late-stage radius change is dominated by the highland thrust faults. The isotropic compressional stress induced by this amount of radial contraction is estimated to be ∼4 MPa, consistent with stress drop estimates from recorded shallow moonquakes. Inconsistency between thermal history models that predict much larger amounts of radial contraction and the absence of degraded, ancient highland fault scarps supports a nonmonotonic lunar thermal evolution, possibly due to the insulating effects of a thick, porous megaregolith. Alternatively, the presence of a strong elastic lithosphere may have inhibited thrust faulting until stresses reached a threshold level in the Copernican era.
Related
- The relation between DCN/DNC ratios and gas temperature in late-stage massive star-forming regions using Yebes observations
- Carbonaceous Chondrites Provide Evidence for Late-stage Planetesimal Formation in a Pressure Bump
- Dust and PAHs in late-stage galaxy evolution: Imprints of TP-AGB dust injection, grain growth and AGN feedback in high-z quiescent galaxies with JWST and ALMA
- Double Gravity-Assist Rendezvous Trajectory to Halley's Comet Using Deep-Space Low Thrust
- Double gravity-assist rendezvous trajectory to Halley’s comet using deep-space low thrust
BibTeX
@article{watters2026thrust,
title = {{Thrust Faulting and the Late-stage Contraction of the Moon}},
author = {T. R. Watters and M. E. Banks and C. A. Nypaver and M. S. Robinson},
journal = {The Planetary Science Journal},
year = {2026},
month = oct,
doi = {10.3847/psj/ae9eae},
url = {https://iopscience.iop.org/article/10.3847/PSJ/ae9eae},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Thrust Faulting and the Late-stage Contraction of the Moon
AU - T. R. Watters
AU - M. E. Banks
AU - C. A. Nypaver
AU - M. S. Robinson
PY - 2026
DA - 2026/10/14
JO - The Planetary Science Journal
DO - 10.3847/psj/ae9eae
UR - https://iopscience.iop.org/article/10.3847/PSJ/ae9eae
AB - Lunar Reconnaissance Orbiter Camera images have revealed thousands of young thrust fault scarps in the highlands and mare. These relatively small-scale faults are the expression of a period of late-stage lunar global contraction. Here we present the most comprehensive assessment of recent thrust faulting on the Moon and its implications for lunar radius change. Combining the estimate of the fractional areal strain of the highlands from the population of lobate thrust fault scarps with the fractional areal strain of the maria from the population of small mare ridge thrust faults, the total areal contractional strain is estimated to be ∼0.0048% to 0.0053%. This areal strain corresponds to a radial contraction of ∼42 to 46 m. Assuming a uniform rate of radius change over the last 400 Ma, the rate of change is estimated to be a maximum of ∼11 cm Ma ⁻¹ . The fractional areal strain of the maria contributes little to the total radius change, thus the late-stage radius change is dominated by the highland thrust faults. The isotropic compressional stress induced by this amount of radial contraction is estimated to be ∼4 MPa, consistent with stress drop estimates from recorded shallow moonquakes. Inconsistency between thermal history models that predict much larger amounts of radial contraction and the absence of degraded, ancient highland fault scarps supports a nonmonotonic lunar thermal evolution, possibly due to the insulating effects of a thick, porous megaregolith. Alternatively, the presence of a strong elastic lithosphere may have inhibited thrust faulting until stresses reached a threshold level in the Copernican era.
SN - 2632-3338
ER -