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Sources of shape variation in lunar impact craters: Fourier shape analysis

1983; Geological Society of America; Volume: 94; Issue: 2 Linguagem: Inglês

10.1130/0016-7606(1983)94 2.0.co;2

1943-2674

Duane T. Eppler, Robert Ehrlich, Dag Nummedal, P. H. Schultz,

Geology and Paleoclimatology Research

Research Article| February 01, 1983 Sources of shape variation in lunar impact craters: Fourier shape analysis DUANE T. EPPLER; DUANE T. EPPLER 1Polar Oceanography Programs, Naval Ocean Research and Development Activity, NSTL Station, Mississippi 39529 Search for other works by this author on: GSW Google Scholar ROBERT EHRLICH; ROBERT EHRLICH 2Department of Geology, University of South Carolina, Columbia, South Carolina 29208 Search for other works by this author on: GSW Google Scholar DAG NUMMEDAL; DAG NUMMEDAL 3Department of Geology, Louisiana State University, Baton Rouge, Louisiana 70803 Search for other works by this author on: GSW Google Scholar PETER H. SCHULTZ PETER H. SCHULTZ 4The Lunar and Planetary Institute, 3303 NASA Road One, Houston, Texas 77058 Search for other works by this author on: GSW Google Scholar Author and Article Information DUANE T. EPPLER 1Polar Oceanography Programs, Naval Ocean Research and Development Activity, NSTL Station, Mississippi 39529 ROBERT EHRLICH 2Department of Geology, University of South Carolina, Columbia, South Carolina 29208 DAG NUMMEDAL 3Department of Geology, Louisiana State University, Baton Rouge, Louisiana 70803 PETER H. SCHULTZ 4The Lunar and Planetary Institute, 3303 NASA Road One, Houston, Texas 77058 Publisher: Geological Society of America First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (1983) 94 (2): 274–291. https://doi.org/10.1130/0016-7606(1983)94 2.0.CO;2 Article history First Online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation DUANE T. EPPLER, ROBERT EHRLICH, DAG NUMMEDAL, PETER H. SCHULTZ; Sources of shape variation in lunar impact craters: Fourier shape analysis. GSA Bulletin 1983;; 94 (2): 274–291. doi: https://doi.org/10.1130/0016-7606(1983)94 2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract R-mode factor analysis of Fourier harmonics that describe the shape-in-plan-view of 716 large (diameter > 15 km) nearside lunar craters shows that two factors explain 84.3% of shape variance observed in the sample. Factor I accounts for 68.2% of the sample variance and describes moderate-scale roughness defined by harmonics 7 through 10. Shape variation described by these harmonics is related to surficial lunar processes of degradation that modify crater shape-in-plan. Dominant among these processes are ejecta scour from large impact events and ongoing aging. Factor II accounts for 16.1% of the observed shape variance and describes polygonal shape elements related to harmonics 2, 3, 4, and 6. Variation in these harmonics is tied to variables that distort the spherical symmetry of crater-forming processes. The dominant contributor among these variables is the nature of geologic structural patterns in impacted material. Unlike transient features described by factor I, polygonal shape elements described by factor II do not change appreciably with time. The permanence of these features and their relation to lunar geologic structure suggest that the shape of old craters carries the imprint of geologic structural relationships present in early lunar crust. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.