ASU is
reporting that "High-resolution photos (taken by a UA camera) of lava flows on Mars reveal coiling spiral
patterns that resemble snail or nautilus shells. Such patterns have been
found in a few locations on Earth, but never before on Mars. The
discovery, made by Arizona State University graduate student Andrew
Ryan, is announced in a paper published April 27, 2012, in the
scientific journal Science. The new result came out of research into possible interactions of
lava flows and floods of water in the Elysium volcanic province of Mars."
The ASU
announcement said that on Earth, lava coils can be found on the Big Island of Hawaii, mainly
on the surface of ropey pahoehoe lava flows. They have also been seen
in submarine lava flows near the Galapagos Rift on the Pacific Ocean
floor. Ryan explained, "The coils form on flows where there's a shear
stress – where flows move past each other at different speeds or in
different directions. Pieces of rubbery and plastic lava crust can
either be peeled away and physically coiled up – or wrinkles in the
lava's thin crust can be twisted around."
[
Right, cooling lava on Mars can form patterns like snail shells when the lava
is pulled in two directions at once. Such patterns, rare on Earth, have
never before been seen on Mars. This image, with more than a dozen lava
coils visible, shows an area in a volcanic region named Cerberus Palus
that is about 500 meters (1640 feet) wide. Photo by:
NASA/JPL-Caltech/UA]
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