Continuing Avalanches
NASA/JPL-Caltech/UArizona
Continuing Avalanches
ESP_016228_2650  Science Theme: Climate Change
Since HiRISE first started finding avalanches on Mars, we have continued searching for them in the most likely places: steep cliffs at the edges of the layered deposits at the North Pole.

These layers are exposed in the scarp face that cuts through them diagonally across this subimage. The bright smoother material at the lower left is at the top of the cliff, and here we have caught another avalanche as it falls down the steep slope towards the upper right of the image.

A large (approximately 200 meters or 600 feet across) cloud of reddish dust has been kicked up at the base of the scarp. Fine tendrils of bright wisps are visible farther up the cliff face—these may be individual falls of material, before spreading out as the avalanche plummets downward.

This might allow scientists to figure out the exact location of the start of the avalanche; for example, which layer it originally came from and how far it fell. This information will help narrow down what triggers these falls: is it seasonal temperature changes in the ice layers, gusts of wind passing over loosened rocks in steep slopes, or something else entirely?

In the upcoming season of spring in the Northern hemisphere, HiRISE will be searching for even more of these events in order to better understand when and where they happen, and why.

Written by: Ingrid Daubar  (25 October 2011)
 
Acquisition date
12 January 2010

Local Mars time
12:36

Latitude (centered)
84.993°

Longitude (East)
151.472°

Spacecraft altitude
319.4 km (198.5 miles)

Original image scale range
32.0 cm/pixel (with 1 x 1 binning) so objects ~96 cm across are resolved

Map projected scale
25 cm/pixel

Map projection
Polarstereographic

Emission angle
1.7°

Phase angle
71.6°

Solar incidence angle
70°, with the Sun about 20° above the horizon

Solar longitude
36.6°, Northern Spring

For non-map projected images
North azimuth:  124°
Sub-solar azimuth:  311.9°
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EDR products
HiView

NB
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

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:
NASA/JPL-Caltech/UArizona

POSTSCRIPT
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.