Cameras orbiting have taken thousands of images that have enabled NASA scientists to put together pieces of Mars’ geologic history. However, most of them reveal landscapes that haven’t changed much in millions of years. Some images taken at different times of year do show seasonal changes from one image to the next; however, it is extremely rare to catch such a dramatic event as an avalanche in action on north pole.
The scarp in this image is on the edge of the dome of layered deposits centered on Mars’ north pole. From top to bottom this impressive cliff is over 700 m (2300 ft) tall and reaches slopes over 60 degrees. The top part of the scarp, to the left of the images, is still covered with bright (white) carbon dioxide frost which is disappearing from the polar regions as spring progresses.
The upper, steepest section, which appears highly fractured due to blocks pulling away from the wall, is the likely source zone for the falls. The precise trigger mechanism is not yet known, although the disappearance of the carbon dioxide frost, the expansion and contraction of the ice in response to temperature differences, a nearby Mars-quake or meteorite impact, and vibrations caused by the first fall in the area, are all possible contributors.
Posted by Casey Kazan from a NASA release.
TrackBack URL for this entry:
Listed below are links to weblogs that reference Avalanche on -How Cool is That!: