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Terra Sabaea is a large area on Mars. Its coordinates are and it covers at its broadest extent. It was named in 1979 after a classic albedo feature on the planet. Terra Sabaea is fairly large and parts of it are found in five quadrangles: Arabia quadrangle, Syrtis Major quadrangle, Iapygia quadrangle, Ismenius Lacus quadrangle, and Sinus Sabaeus quadrangle. Wikiarabiaboundaries.jpg|MOLA map showing boundaries of Terra Sabaea and other regions ==Glaciers== Some landscapes look just like glaciers moving out of mountain valleys on Earth. Some have a hallowed out appearance, looking like a glacier after almost all the ice has disappeared. What is left are the moraines—the dirt and debris carried by the glacier. The center is hollowed out because the ice is mostly gone.〔Milliken, R., J. Mustard, D. Goldsby. 2003. Viscous flow features on the surface of Mars: Observations from high-resolution Mars Orbiter Camera (MOC) images. J. Geophys. Res. 108. doi:10.1029/2002JE002005.〕 These supposed alpine glaciers have been called glacier-like forms (GLF) or glacier-like flows (GLF).〔Arfstrom, J and W. Hartmann. 2005. Martian flow features, moraine-like ridges, and gullies: Terrestrial analogs and interrelationships. Icarus 174, 321-335.〕 Glacier-like forms are a later and maybe more accurate term because we cannot be sure the structure is currently moving.〔Hubbard B., R. Milliken, J. Kargel , A. Limaye, C. Souness . 2011. Geomorphological characterisation and interpretation of a mid-latitude glacier-like form: Hellas Planitia, Mars Icarus 211, 330–346〕 Another, more general term sometimes seen in the literature is viscous flow features (VFF).〔 A variety of other features on the surface have also been interpreted as directly linked to flowing ice, such as fretted terrain,〔Lucchitta, Baerbel K. "Ice and debris in the fretted terrain, Mars." Journal of Geophysical Research: Solid Earth (1978–2012) 89.S02 (1984): B409-B418.〕 lineated valley fill,〔G.A. Morgan, J.W. Head, D.R. Marchant Lineated valley fill (LVF) and lobate debris aprons (LDA) in the Deuteronilus Mensae northern dichotomy boundary region, Mars: Constraints on the extent, age and episodicity of Amazonian glacial events Icarus, 202 (2009), pp. 22–38〕〔D.M.H. Baker, J.W. Head, D.R. Marchant Flow patterns of lobate debris aprons and lineated valley fill north of Ismeniae Fossae, Mars: Evidence for extensive mid-latitude glaciation in the Late Amazonian Icarus, 207 (2010), pp. 186–209〕 concentric crater fill,〔Milliken, R. E., J. F. Mustard, and D. L. Goldsby. "Viscous flow features on the surface of Mars: Observations from high-resolution Mars Orbiter Camera (MOC) images." Journal of Geophysical Research 108.E6 (2003): 5057.〕〔Levy, Joseph S., James W. Head, and David R. Marchant. "Concentric crater fill in Utopia Planitia: History and interaction between glacial “brain terrain” and periglacial mantle processes." Icarus 202.2 (2009): 462-476.Levy, Joseph S., James W. Head, and David R. Marchant. "Concentric crater fill in Utopia Planitia: History and interaction between glacial “brain terrain” and periglacial mantle processes." Icarus 202.2 (2009): 462-476.〕 and arcuate ridges.〔J. Arfstrom, W.K. Hartmann Martian flow features, moraine-like ridges, and gullies: Terrestrial analogs and interrelationships Icarus, 174 (2005), pp. 321–335〕 A variety of surface textures seen in imagery of the midlatitudes and polar regions are also thought to be linked to sublimation of glacial ice.〔〔Hubbard, Bryn, et al. "Geomorphological characterisation and interpretation of a mid-latitude glacier-like form: Hellas Planitia, Mars." Icarus 211.1 (2011): 330-346.〕 The pictures below show features believed to be glaciers—some may still contain ice; in others the ice has probably largely disappeared. Since ice may be present under just a few meters of debris, these places could be used to supply future colonists with water. Wikielephantglacier.jpg|Elephant Foot Glacier in the Earth's Arctic, as seen by Landsat 8. This picture shows several glaciers that have the same shape as many features on Mars that are believed to also be glaciers. Image:Glacier as seen by ctx.JPG|Mesa in Ismenius Lacus quadrangle, as seen by CTX. Mesa has several glaciers eroding it. One of the glaciers is seen in greater detail in the next two images from HiRISE. Image:Wide view of glacier showing image field.JPG|Glacier as seen by HiRISE under the HiWish program. Area in rectangle is enlarged in the next photo. Zone of accumulation of snow at the top. Glacier is moving down valley, then spreading out on plain. Evidence for flow comes from the many lines on surface. Location is in Protonilus Mensae in Ismenius Lacus quadrangle. Image:Glacier close up with hirise.JPG|Enlargement of area in rectangle of the previous image. On Earth the ridge would be called the terminal moraine of an alpine glacier. Picture taken with HiRISE under the HiWish program. Image:20769flow_features.jpg|Remains of glaciers, as seen by HiRISE under the HiWish program. Image:25305glacierend.jpg|End of a glacier, as seen by HiRISE under HiWish program. Surface to the right of the end moraine exhibits patterned ground which is common where ground water has frozen. Wikifrettedctxp22.jpg|Wide CTX view showing mesa and buttes with Lobate debris aprons and lineated valley fill around them. Location is Ismenius Lacus quadrangle. WikiESP 020769 2225fretted.jpg|Close-up of Lineated Valley Fill (LVF), as seen by HiRISE under HiWish program Note: this is an enlargement of the previous CTX image. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Terra Sabaea」の詳細全文を読む スポンサード リンク
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