Persistent Link:
http://hdl.handle.net/10150/185087
Title:
Tectonics of one-plate planets.
Author:
Janes, Daniel Mark.
Issue Date:
1990
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
The Voyager 2 encounter with Neptune and its moons in August of 1989 completed the discovery phase of planetary exploration. In the 25 years since Mariner 4 returned the first images of another planet, geophysical models for such basic processes as mantle convection and loading which were developed for the Earth have been strained beyond their limits by features such as the Tharsis rise on Mars and the coronae of Miranda which cover as much as a quarter of their planetary circumference. In this work I develop a general planetary shell model in spherical coordinates that is capable of treating shells of arbitrary thickness and driving forces of arbitrary breadth. I then present a methodology for finding the forces exerted on the shell from two processes. I first develop a treatment for mantle convection driven by a density anomaly within a viscous mantle. This model is applied to the small moon of Uranus, Miranda, to study the three large coronae which dominate its surface and for which several competing hypotheses were offered, two of which invoked mantle convection driven by density anomalies of opposite sign. I then develop a general model for loading of the lithosphere and examine the effects of a range of load breadths and lithosphere thicknesses. I map out the combinations of these two variables where classical approximations such as the flat-plate and thin-shell models are applicable as well as determine the nature and extent of the transition between these two regimes. Finally, I employ finite element modeling to investigate the coronae on Venus, showing that morphological aspects of these features reported in the literature can be produced by flexure of the lithosphere beneath a volcanic load and gravitational sliding of a cooled crust off these volcanic mounds. I then, however, produce independent characteristic topographic profiles for three of the more regular coronae which question how typical the reported morphologies are in the coronae in general.
Type:
text; Dissertation-Reproduction (electronic)
Keywords:
Geology
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Planetary Sciences; Graduate College
Degree Grantor:
University of Arizona
Advisor:
Melosh, H. Jay

Full metadata record

DC FieldValue Language
dc.language.isoenen_US
dc.titleTectonics of one-plate planets.en_US
dc.creatorJanes, Daniel Mark.en_US
dc.contributor.authorJanes, Daniel Mark.en_US
dc.date.issued1990en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractThe Voyager 2 encounter with Neptune and its moons in August of 1989 completed the discovery phase of planetary exploration. In the 25 years since Mariner 4 returned the first images of another planet, geophysical models for such basic processes as mantle convection and loading which were developed for the Earth have been strained beyond their limits by features such as the Tharsis rise on Mars and the coronae of Miranda which cover as much as a quarter of their planetary circumference. In this work I develop a general planetary shell model in spherical coordinates that is capable of treating shells of arbitrary thickness and driving forces of arbitrary breadth. I then present a methodology for finding the forces exerted on the shell from two processes. I first develop a treatment for mantle convection driven by a density anomaly within a viscous mantle. This model is applied to the small moon of Uranus, Miranda, to study the three large coronae which dominate its surface and for which several competing hypotheses were offered, two of which invoked mantle convection driven by density anomalies of opposite sign. I then develop a general model for loading of the lithosphere and examine the effects of a range of load breadths and lithosphere thicknesses. I map out the combinations of these two variables where classical approximations such as the flat-plate and thin-shell models are applicable as well as determine the nature and extent of the transition between these two regimes. Finally, I employ finite element modeling to investigate the coronae on Venus, showing that morphological aspects of these features reported in the literature can be produced by flexure of the lithosphere beneath a volcanic load and gravitational sliding of a cooled crust off these volcanic mounds. I then, however, produce independent characteristic topographic profiles for three of the more regular coronae which question how typical the reported morphologies are in the coronae in general.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.subjectGeologyen_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplinePlanetary Sciencesen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorMelosh, H. Jayen_US
dc.contributor.committeememberLunine, Jonathan I.en_US
dc.contributor.committeememberSinger, Robert B.en_US
dc.contributor.committeememberChase, Clement G.en_US
dc.contributor.committeememberRichardson, Randall M.en_US
dc.identifier.proquest9028160en_US
dc.identifier.oclc708268978en_US
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