أخدود (المريخ)
أخاديد المريخ Martian gullies، هي شبكات صغيرة متقطعة من القنوات الضيقة والمنحدرات الرسوبية المرتبطة بها، عُثر عليها على كوكب المريخ. سميت على اسم شبيهاتها من الأخاديد الأرضية. أكتشفت لأول مرة في صور التقطها مساح المريخ العالمي، وتقع على المنحدرات، خاصة على جدران الحفر. يكون عاد لكل أخدود كوة تصريف على رأسه، ومئزر مروحي الشكل عند قاعدته، ومجرى فردي من القنوات يصل بين الأخدودين، مما يعطي الأخدود بالكامل شكل الساعة الرملية.[1] يقدر أن عمر هذه الأخاديد صغير نسبياً لأن بها عدد قليل من الحفر، إن وجدت. كما تم العثور على مجموعة فرعية من الأخاديد قبالة الكثبان الرملية،[2] والتي تعتبر في حد ذاتها صغيرة صغيرة العمر نسبياً.
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
التشكل
Gullies on wall of crater, as seen by HiRISE under HiWish program Location is the Mare Acidalium quadrangle.
Close-up of gully channels, as seen by HiRISE under HiWish program. This image shows many streamlined forms and some benches along a channel. These features suggest formation by running water. Benches are usually formed when the water level goes down a bit and stays at that level for a time. Picture was taken with HiRISE under HiWish program. Location is the Mare Acidalium quadrangle. Note this is an enlargement of a previous image.
Gullies in crater in Phaethontis quadrangle, as seen by HiRISE under HiWish program
Close-up of channels in gullies showing that the paths of the channels changed over time. This feature suggest formation by running water with a high load of sediment. Picture was taken with HiRISE under HiWish program. Location is the Mare Acidalium quadrangle. Note this is an enlargement of a previous image in Phaethontis quadrangle.
Gullies in crater, as seen by HiRISE under HiWish program. Location is Eridania quadrangle.
Close up of gullies in crater showing channels within larger valleys and curves in channels. These characteristics suggest they were made by flowing water. Note: this is an enlargement of the previous image by HiRISE under HiWish program. Location is Eridania quadrangle.
Close up of gully network showing branched channels and curves; these characteristics suggest creation by a fluid. Note: this is an enlargement of a previous wide view of gullies in a crater, as seen by HiRISE under HiWish program. Location is Eridania quadrangle.
المياه الجوفية
Gully on mound as seen by Mars Global Surveyor, under the MOC Public Targeting Program. Images of gullies on isolated peaks, like this one, are difficult to explain with the theory of water coming from aquifers because aquifers need large collecting areas.
Gullies in Ross Crater, as seen by HiRISE under the HiWish program. Because the gullies are on the narrow rim of a crater and they start at different heights, this example is not consistent with the model of gullies being caused by aquifers.
Gullies in two levels of a crater wall, as seen by HiRISE under HiWish program. Gullies at two levels suggests they were not made with an aquifer, as was first suggested. Location is Phaethontis quadrangle.
Lohse Crater Gullies on Central Peak. Image located in Argyre quadrangle. Having gullies on a central peak runs counter to the idea that they were formed by an aquifer, as was first suggested.
كثافة السلوج
انصهار الجليد الأرضي
أحدث التغيرات في الأخاديد
كيفية تغير آثار الإنحدار على المناخ
صور الأخاديد
Group of gullies on north wall of crater that lies west of the crater Newton (41.3047 degrees south latitude, 192.89 east longitide). Image taken with Mars Global Surveyor under the MOC Public Targeting Program.
Atlantis Chaos, as seen by HiRISE. Click on image to see mantle covering and possible gullies. The two images are different parts of the original image. They have different scales.
Gullies in a trough and nearby crater, as seen by HiRISE under the HiWish program. Scale bar is 500 meters long.
Gullies near Newton Crater, as seen by HiRISE, under the HiWish program. Place where there was an old glacier is labeled.
HiRISE image, taken under HiWish program, of gullies in a crater in Terra Sirenum.
Gullies with remains of a former glacier in crater in Terra Sirenum, as seen by HiRISE under HiWish program.
Gullies in a crater in Terra Sirenum, as seen by HiRISE under the HiWish Program.
Gullies in crater in Phaethontis quadrangle, as seen by HiRISE under HiWish program
Close-up of channels in gullies showing that the paths of the channels changed over time. This feature suggest formation by running water with a high load of sediment. Picture was taken with HiRISE under HiWish program. Location is the Mare Acidalium quadrangle. Note this is an enlargement of a previous image in Phaethontis quadrangle.
Gullies in a crater in Eridania, north of the large crater Kepler. Also, features that may be remains of old glaciers are present. One, to the right, has the shape of a tongue. Image taken with Mars Global Surveyor under the MOC Public Targeting Program.
HiRISE image showing gullies. The scale bar is 500 meters. Picture taken under the HiWish program.
Gullies and layers in mantle on a wall, as seen by HiRISE under HiWish program. Location is Eridania quadrangle.
Jezza Crater,as seen by HiRISE. North wall (at top) has gullies. Dark lines are dust devil tracks. Scale bar is 500 meters long.
Scene in Argyre quadrangle with gullies, alluvival fans, and hollows, as seen by HiRISE under HiWish program. Enlargements of parts of this image are below.
Gullies in Nereidum Montes, as seen by HiRISE under HiWish program.
Wide view of gullies in Arkhangelsky Crater, as seen by HiRISE under HiWish program
Close-up of small channels in gullies in Arkhangelsky Crater, as seen by HiRISE under HiWish program Patterned ground in the shape of polygons can be seen to the right. Note: this is an enlargement of the previous image from Arkhangelsky Crater.
Gullies and massive flow of material, as seen by HiRISE under HiWish program. Gullies are enlarged in next two images. Location is Bamberg crater.
Gullies on wall of crater, as seen by HiRISE under HiWish program Location is the Mare Acidalium quadrangle.
Close-up of gully channels, as seen by HiRISE under HiWish program. This image shows many streamlined forms and some benches along a channel. These features suggest formation by running water. Benches are usually formed when the water level goes down a bit and stays at that level for a time. Picture was taken with HiRISE under HiWish program. Location is the Mare Acidalium quadrangle. Note this is an enlargement of a previous image.
A variety of gullies originating at different levels are visible in this HiRISE image that was taken under the HiWish program.
أخدود نواكيس الرباعي
أخدود كاسيوس الرباعي
انظر أيضاً
- أرگير الرباعي
- مناخ المريخ
- إريدانيا الرباعي
- جيولوجيا المريخ
- فايثونتيس الرباعي
- ثوماسيا الرباعي
- المياه على المريخ
المصادر
- ^ Malin, M., Edgett, K. 2000. Evidence for recent groundwater seepage and surface runoff on Mars. Science 288, 2330–2335.
- ^ G. Jouannic, J.Gargani, F. Costard, G. Ori, C. Marmo, F. Schmidt, A. Lucas (2012). "Morphological and mechanical characterization of gullies in a periglacial environment : The case of the Russell crater dune (Mars)". Planetary and Space Science. 71: 38–54.
{{cite journal}}
: CS1 maint: multiple names: authors list (link)
وصلات خارجية
- VEDIE et al., 2008 : Laboratory simulations of martian gullies on the Russel crater sand dunes <http://www.agu.org/pubs/crossref/2008/2008GL035638.shtml>
- [1] Gives a general review of many of the theories involving the origin of gullies.
- Dickson, J; Head, J; Kreslavsky, M (2007). "Martian gullies in the southern mid-latitudes of Mars: Evidence for climate-controlled formation of young fluvial features based upon local and global topography" (PDF). Icarus. 188: 315–323. Bibcode:2007Icar..188..315D. doi:10.1016/j.icarus.2006.11.020. Gives a good review of the history of the discovery of gullies.