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Moreux Crater is a crater in the Ismenius Lacus quadrangle on Mars with a diameter of 138 km. It is located at 42.1° north latitude and 315.6° west longitude It was named after Theophile Moreux, a French astronomer and meteorologist (1867–1954). Wikilyotmola.jpg|MOLA map of Moreux Crater and other nearby craters. Colors indicate elevations. == Glaciers == Moreux Crater's appearance has been shaped by the action of glaciers. Recent research, using a variety of images from various cameras, discovered extensive glacial modification of the surfaces of Moreux Crater's rim, wall, and central peak. These changes were caused by the emplacement of ice-rich material when the climate underwent major changes.〔Rishitosh K., S. Sinha, S. Murty. 2015. Amazonian modification of Moreux crater: Record of recent and episodic glaciation in the Protonilus Mensae region of Mars. Icarus 245:122-144.〕 Glaciers modified large areas of the surface of Mars. Many places are believed to still contain enormous amounts of water ice that was associated with glaciers.〔ISBN 0-8165-1257-4〕〔http://www.esa.int/SPECIALS/Mars_Express/SEMBS5V681F_0.html〕 Many craters contain large amounts of ice. If one measures the diameter of a crater, the original depth can be estimated with various ratios. Because of this relationship, researchers have found that many Martian craters contain a great deal of material; much of it is believed to be ice deposited when the climate was different.〔Garvin, J., et al. 2002. Global geometric properities of martian impact craters. Lunar Planet Sci. 33. Abstract @1255.〕 Glaciers have shaped much of the fretted terrain. It would be difficult to take a hike on the fretted terrain because the surface is folded, pitted, and often covered with linear striations. The striations show the direction of movement. Much of this rough texture is due to sublimation of buried ice. When the ice transitions directly into a gas it leaves behind an empty space. Overlying material then collapses into the void.〔http://hirise.lpl.arizona.edu/PSP_009719_2230〕 Glaciers are not pure ice; they contain dirt and rocks. At times, they will dump their load of materials into ridges. Such ridges are called moraines. Some places on Mars have groups of ridges that are twisted around; this may have been due to more movement after the ridges were put into place. Sometimes chunks of ice fall from the glacier and get buried in the land surface. When they melt and more or less round hole remains.〔http://hirise.lpl.arizona.edu/PSP_006278_2225〕 On Earth we call these features kettles or kettle holes. Mendon Ponds Park in upstate NY has preserved several of these kettles. The picture from HiRISE below shows possible kettles in Moreux Crater. Image:Moreux Crater moraines.JPG|Moreux Crater moraines and kettle holes, as seen by HiRISE. Moreuxctx2876.jpg|Western edge of Moreux Crater, as seen by CTX (camera), on the Mars Reconnaissance Orbiter. Arrows indicate probable glacial moraines. Crater floor is to the right. WikimoreuxESP 034918 2230.jpg|Wide, glacial valleys in Moreux Crater, as seen by HiRISE under HiWish program. Impact craters generally have a rim with ejecta around them, in contrast volcanic craters usually do not have a rim or ejecta deposits. As craters get larger (greater than 10 km in diameter) they usually have a central peak.〔http://www.lpi.usra.edu/publications/slidesets/stones/〕 The peak is caused by a rebound of the crater floor following the impact. Sometimes craters expose layers that were buried. Rocks from deep underground are tossed onto the surface. Hence, craters can show us what lies deep under the surface. 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「Moreux (crater)」の詳細全文を読む スポンサード リンク
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