Lobate Debris Apron in Tempe Terra/Mareotis Fossae
NASA/JPL/University of Arizona
Lobate Debris Apron in Tempe Terra/Mareotis Fossae
PSP_001390_2290  Science Theme: Mass Wasting Processes
Italian  Spanish 


800  1024  
1152  1280  
1440  1600  
1920  2048  


PDF, 11 x 17 in  
This image shows a portion of a large lobate debris apron along the bottom of a hill in the Tempe Terra/Mareotis Fossae region of Mars.

Debris aprons were first discovered in regions of "fretted terrain" from analyses of images sent back by the Viking Orbiter spacecrafts in the 1970s. Features in areas of fretted terrain appear "softened" as if some geologic process(es) had smoothed and rounded features that normally would be sharply defined, such the crest of a narrow, steep ridge.

Scientists inferred that the processes causing this degradation must have involved the incorporation and creep of ice in the surface materials. If so, these mixtures of ice and debris could have flowed away from topographically high areas leaving features much less sharply-defined.

The flow behavior described here is similar to slow-moving glacial or permafrost features on Earth. The debris apron in the upper left of the image also has several subtle "ridge" features on its surface from low sun illumination. The ridges are roughly parallel to the base of the hill and their shapes mimic one another along their lengths.

Similar ridges are seen on other debris aprons in this region where the aprons are located directly below large piles of debris accumulating along the bottom of hillslopes. These observations have led to the hypothesis that ridges on debris aprons are accumulated piles of debris from a period of abnormally high erosion. If this was indeed the case, each ridge may indicate a change in the climate or local environment that would have implications for our overall understanding of the Martian climate.

Written by: Frank Chuang   (2 December 2009)

Click to share this post on Twitter Click to share this post on Facebook Click to share this post on Google+ Click to share this post on Tumblr

 Image Products: All image links are drag & drop for HiView, or click to download
B&W: map projected  non-map

IRB color: map projected  non-map

Merged IRB: map projected

Merged RGB: map projected

RGB color: non-map projected

B&W: map-projected (537MB)

IRB color: map-projected (314MB)
B&W: map-projected  (257MB),
non-map  (176MB)

IRB color: map projected  (89MB)
non-map  (232MB)

Merged IRB: map projected  (164MB)

Merged RGB: map-projected  (170MB)

RGB color: non map-projected  (223MB)
B&W label
Color label
Merged IRB label
Merged RGB label
EDR products

About color products (PDF)
HiView main page

 Observation Toolbox
Acquisition date:12 November 2006 Local Mars time:15:20
Latitude (centered):48.878° Longitude (East):283.879°
Range to target site:301.0 km (188.1 miles)Original image scale range:from 30.1 cm/pixel (with 1 x 1 binning) to 60.2 cm/pixel (with 2 x 2 binning)
Map projected scale:25 cm/pixel and North is upMap projection:Equirectangular
Emission angle:2.6° Phase angle:48.4°
Solar incidence angle:51°, with the Sun about 39° above the horizon Solar longitude:134.4°, Northern Summer

Context map

Usage Policy
All of the images produced by HiRISE and accessible on this site are within the public domain: there are no restrictions on their usage by anyone in the public, including news or science organizations. We do ask for a credit line where possible: Image: NASA/JPL/University of Arizona
For information about NASA and agency programs on the Web, visit: http://www.nasa.gov. NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, Calif., manages the Mars Reconnaissance Orbiter for NASA's Science Mission Directorate, Washington. Lockheed Martin Space Systems is the prime contractor for the project and built the spacecraft. The HiRISE camera was built by Ball Aerospace and Technology Corporation and is operated by the University of Arizona. The image data were processed using the U.S. Geological Survey’s ISIS3 software.