Lava Coils Found on Mars

Posted on April 26, 2012

High-resolution photos (see here and here) of lava flows on Mars reveal coiling spiral patterns that resemble snail or nautilus shells.

Patterns like these have been found in a few locations on Earth, but they have never been seen on Mars before. The discovery came out of research into possible interactions of lava flows and floods of water in the Elysium volcanic province of Mars.

The lava coils on Mars are much bigger than the coils seen on Earth. The largest lava coil on Mars is 30 meters across, which is much bigger than any on Earth.

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.

Ryan says, "The coils become noticeable in the full-resolution HiRISE image only when you really zoom in. They also tend to blend in with the rest of the light-gray terrain - that is, until you stretch the contrast a bit. I don't find it surprising that these were overlooked in the past. I nearly missed them too."

On Earth, these lava coils can be found on the Big Island of Hawaii, mainly on the surface of ropey pahoehoe lava flows. A lava coil on the surface of the 1974 Hawaiian pahoehoe lava flow is pictured above. They have also been seen in submarine lava flows near the Galapagos Rift on the Pacific Ocean floor.

Ryan says, "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."

Philip Christensen, Regents' Professor of Geological Sciences at ASU, is the second author on the paper. Ryan and Christensen's work has inventoried nearly 200 lava coils in the Cerberus Palus region alone. They expect to find more in Elysium as the HiRISE image coverage grows over time.

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