Warm-Season Flows in Cold-Season Ravines
NASA/JPL/University of Arizona
Warm-Season Flows in Cold-Season Ravines
ESP_040590_1335  Science Theme: Mass Wasting Processes
twitter  •  facebook  •  tumblr

HICLIP
1080p (MP4)
Audio (MP3)

WALLPAPER
800
1024
1152
1280
1440
1600
1920
2048
2560
2880

HIFLYER
PDF (11 x 17)

HISLIDES
PowerPoint
Keynote
PDF

Ravines (or very large gullies) are actively forming on Mars during the coldest times of year, when carbon dioxide frost aids mass wasting.

However, some of these ravines also show activity in the warmest time of year, in the form of recurring slope lineae (RSL); dark, narrow flows in some alcoves that flow part way down the channels. Few topographic changes have been seen in association with RSL, and they appear to be seeps of water that seasonally extend down slopes, then fade when inactive, and recur each warm season. Could the RSL activity carve the ravines?

In some places the RSL extend to the ends of the fans and appear to match in scale, and perhaps gradually form the ravines. In other places, such as this image, the ravines are much larger than the RSL, so presently-observed RSL flow did not produce the larger landforms, but maybe the flow was greater in the past or maybe the RSL just follow the topography created by other processes.

The largest ravines are on pole-facing slopes in the middle latitudes, where RSL have never been seen to form, unless the ravine creates a small equator-facing slope.

Written by: Alfred McEwen (audio: Tre Gibbs)  (6 May 2015)
 
Acquisition date
25 March 2015

Local Mars time:
14:25

Latitude (centered)
-46.153°

Longitude (East)
18.923°

Spacecraft altitude
255.8 km (159.9 miles)

Original image scale range
25.6 cm/pixel (with 1 x 1 binning) so objects ~77 cm across are resolved

Map projected scale
25 cm/pixel and North is up

Map projection
Equirectangular

Emission angle:
9.5°

Phase angle:
49.3°

Solar incidence angle
41°, with the Sun about 49° above the horizon

Solar longitude
314.2°, Northern Winter

For non-map projected images
North azimuth:  96°
Sub-solar azimuth:  36.5°
JPEG
Black and white
map projected  non-map

IRB color
map projected  non-map

Merged IRB
map projected

Merged RGB
map projected

RGB color
non-map projected

JP2
Black and white
map-projected   (617MB)

IRB color
map-projected   (367MB)

JP2 EXTRAS
Black and white
map-projected  (287MB)
non-map           (351MB)

IRB color
map projected  (107MB)
non-map           (294MB)

Merged IRB
map projected  (167MB)

Merged RGB
map-projected  (160MB)

RGB color
non map           (292MB)
ADDITIONAL INFORMATION
B&W label
Color label
Merged IRB label
Merged RGB label
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/University of Arizona

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.