Fault dislocation modeled structure of lobate scarps from Lunar Reconnaissance Orbiter Camera digital terrain models

N. R. Williams, T. R. Watters, M. E. Pritchard, M. E. Banks, James Bell

Research output: Contribution to journalArticlepeer-review

22 Scopus citations

Abstract

Before the launch of the Lunar Reconnaissance Orbiter, known characteristics of lobate scarps on the Moon were limited to studies of only a few dozen scarps revealed in Apollo-era photographs within ~20° of the equator. The Lunar Reconnaissance Orbiter Camera now provides meter-scale images of more than 100 lobate scarps, as well as stereo-derived topography of about a dozen scarps. High-resolution digital terrain models (DTMs) provide unprecedented insight into scarp morphology and dimensions. Here, we analyze images and DTMs of the Slipher, Racah X-1, Mandel'shtam-1, Feoktistov, Simpelius-1, and Oppenheimer F lobate scarps. Parameters in fault dislocation models are iteratively varied to provide best fits to DTM topographic profiles to test previous interpretations that the observed landforms are the result of shallow, low-angle thrust faults. Results suggest that these faults occur from the surface down to depths of hundreds of meters, have dip angles of 35-40°, and have typical maximum slips of tens of meters. These lunar scarp models are comparable to modeled geometries of lobate scarps on Mercury, Mars, and asteroid 433 Eros, but are shallower and ~10° steeper than geometries determined in studies with limited Apollo-era data. Frictional and rock mass strength criteria constrain the state of global differential stress between 3.5 and 18.6 MPa at the modeled maximum depths of faulting. Our results are consistent with thermal history models that predict relatively small compressional stresses that likely arise from cooling of a magma ocean. Key pointsFaults steeper, shallower, and have less shortening than previous estimates.Lobate scarps suggest a <20 MPa global differential stress.First topography-constrained fault dislocation models for lunar lobate scarps.

Original languageEnglish (US)
Pages (from-to)224-233
Number of pages10
JournalJournal of Geophysical Research E: Planets
Volume118
Issue number2
DOIs
StatePublished - Feb 2013

Keywords

  • DTM
  • LROC
  • Moon
  • lobate scarp
  • tectonics

ASJC Scopus subject areas

  • Geophysics
  • Forestry
  • Oceanography
  • Aquatic Science
  • Ecology
  • Water Science and Technology
  • Soil Science
  • Geochemistry and Petrology
  • Earth-Surface Processes
  • Atmospheric Science
  • Earth and Planetary Sciences (miscellaneous)
  • Space and Planetary Science
  • Palaeontology

Fingerprint Dive into the research topics of 'Fault dislocation modeled structure of lobate scarps from Lunar Reconnaissance Orbiter Camera digital terrain models'. Together they form a unique fingerprint.

Cite this