عنوان

Investigations in Martian geology. Part 1:

Number

TLpq303796100

.Language of Text, Soundtrack etc

انگلیسی

Title Proper

Investigations in Martian geology. Part 1:

General Material Designation

[Thesis]

First Statement of Responsibility

J. M. Moore

Title Proper by Another Author

Nature of the mantling deposit in the heavily cratered terrain of northeastern Arabia, Mars. Part 2: Experimental studies of clean and dust-or-sand-covered ice sublimation under Mars-like conditions

Name of Publisher, Distributor, etc.

Arizona State University

Date of Publication, Distribution, etc.

1990

Specific Material Designation and Extent of Item

179

Dissertation or thesis details and type of degree

Ph.D.

Body granting the degree

Arizona State University

Text preceding or following the note

1990

Text of Note

This dissertation consists of two parts. Part I describes the geomorphology of a portion of northeastern Arabia, Mars. This surface is covered by an extensive, layered deposit which has been, in places, substantially eroded. Speculative origins for the deposit include formation as a differentially welded pyroclastic tuff, or a differentially compacted, zonally indurated aeolian dust deposit. Part II is an experimental study of the sublimation rate of H2O ice, both from clean surfaces and from under thin layers of dust or sand, in a Mars-like environment. The major conclusions drawn from the results of this experiment are: (1) even very thin layers of dust greatly lower the sublimation rate of an underlying ice substrate being heated from above, whereas thin layers of sand suppress the sublimation rate of underlying ice being heated from above to a significantly lesser extent; (2) thin layers of dust or sand only mildly suppress the sublimation rate of an underlying ice substrate when sample is wholly isothermal; (3) even a low-flux, desiccated gas flow over the sample surface significantly increases the sublimation rate of any given sample; (4) dry sublimation of ice underlying thin layers of dust or sand may modify the surface texture as a function of particle cohesion and as the ratio of particle layer thickness to the amount by which the surface was lowered; and (5) the actual sublimation rate of clean ice is several factors lower that the sublimation rate predicted by a commonly used formula.

Astronomy

Astrophysics

Astrophysics

Earth sciences

Geology

Pure sciences

J. M. Moore

Electronic name

p

[Thesis]

276903

a

Y