Graben in Memnonia Region
Graben in Memnonia Region
PSP_005442_1660  Science Theme: Tectonic Processes
This HiRISE image shows a graben (roughly 2.5 kilometers or 1.6 miles wide) cutting a ridge near Memnonia Sulci, a region of Mars west of the massive Tharsis volcanic province.

A graben is a trough created when two normal faults (faults dipping at an angle, with the overhanging wall sliding downwards) opposite each other lower the block of rock in between them. They are commonly associated with the tectonically-driven extension of a region and are also found in volcanic areas. Graben occur on many planets and moons, including Earth.

In this case, the graben (running roughly east-west, indicating extension in the north-south direction) is cutting a ridge, showing that the graben is more recent. The ridge may also be tectonic in origin, representing a different epoch and different type of tectonic activity.

Relationships like this can be used to determine the sequence of events in the history of the region. The graben walls can also expose the local rocks at depth; in this case there is no obvious indication of layering.

Written by: Colin Dundas  (17 October 2007)
Acquisition date
24 September 2007

Local Mars time

Latitude (centered)

Longitude (East)

Spacecraft altitude
262.8 km (163.4 miles)

Original image scale range
26.5 cm/pixel (with 1 x 1 binning) so objects ~79 cm across are resolved

Map projected scale
25 cm/pixel and North is up

Map projection

Emission angle

Phase angle

Solar incidence angle
34°, with the Sun about 56° above the horizon

Solar longitude
319.4°, Northern Winter

For non-map projected images
North azimuth:  97°
Sub-solar azimuth:  357.1°
Black and white
map projected  non-map

IRB color
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Merged IRB
map projected

Merged RGB
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RGB color
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Black and white
map-projected   (1965MB)

IRB color
map-projected   (672MB)

Black and white
map-projected  (766MB)
non-map           (1079MB)

IRB color
map projected  (359MB)
non-map           (876MB)

Merged IRB
map projected  (513MB)

Merged RGB
map-projected  (491MB)

RGB color
non map           (861MB)
B&W label
Color label
Merged IRB label
Merged RGB label
EDR products

IRB: infrared-red-blue
RGB: red-green-blue
About color products (PDF)

Black & white is 5 km across; enhanced color about 1 km
For scale, use JPEG/JP2 black & white map-projected images

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:
NASA/JPL/University of Arizona

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. The HiRISE camera was built by Ball Aerospace and Technology Corporation and is operated by the University of Arizona.