Landslides at the foot of Olympus Mons

Mars is residence to the most important volcanoes within the Photo voltaic System. The tallest of those is Olympus Mons, a large protect volcano noticed in 1971 by NASA’s Mariner 9 spacecraft. Olympus Mons is 21.9 km tall at its peak, about 2.5 instances larger than Earth’s Mount Everest rises above sea stage.

Mariner scientists spied not simply Olympus Mons’s peak but in addition its environment, noticing an ‘aureole’ spreading out from the volcano’s base for a whole lot of kilometres. This aureole in flip surrounds the volcano’s ‘basal scarp’, a right away perimeter round Olympus Mons that’s remarkably steep, hitting seven km tall in some locations.

These new pictures present a crumpled characteristic named Lycus Sulci, on the perimeters of the aureole; the volcano itself is situated out of body to the underside left (south-east), many a whole lot of km away.

Catastrophic collapse

The aureole – seen particularly nicely on this 2004 picture from NASA’s Mars Orbiter Laser Altimeter, and within the contextual map related to this new Mars Categorical launch – tells the story of how Olympus Mons’s decrease flanks catastrophically collapsed a number of 100 million years in the past. 

Massive quantities of lava as soon as flowed down the volcano, triggering landslides that tumbled down its flanks to fulfill bedrock – on this case, bedrock containing ice and water.

The swelteringly scorching lava prompted this ice to soften and turn into unstable; in consequence, the rocky rim of Olympus Mons broke off and partially slid away. This collapse got here within the type of large rockfalls and landslides, which slipped downwards and unfold broadly throughout the encompassing plains.

Because the landslides moved away from Olympus Mons and travelled throughout the martian floor they turned alternately compressed and stretched – crumpled and pulled aside. This created the attribute wrinkles seen in these new pictures of Lycus Sulci.

Weakened by wind

Following its formation, Lycus Sulci turned much more outstanding over time as wind whipped throughout the martian floor, eroding its materials. This wind additionally picked up mud and carried it far and large throughout Mars, later scattering this nice sand over close by hills and ridges.

Single landslides of the type skilled by Olympus Mons could be a whole lot of metres thick. Nonetheless, for this behemoth, which noticed a number of colossal and overlapping collapses, they are often as much as two kilometres thick.

This superposition of landslides could be seen clearly within the annotated picture; the wrinkled terrain to the suitable of the body is older than the overlying crumples to the left, which flowed down the volcano’s slopes later in Mars’s historical past.

Comparable however alien

Regardless of their otherworldly dimensions, Mars’s volcanoes present similarities to these we see on Earth. Comparable landslides – in kind, if not in scale – could be seen across the volcanic islands of Hawaii and the Canary Islands, which have seen giant rockfalls prior to now.

One other characteristic highlighting the really immense proportions of Olympus Mons could be seen to the suitable of the body in Yelwa Crater. Though dwarfed by the intensive Lycus Sulci, this crater is over 8 km in diameter – simply shy of Mount Everest’s elevation above sea stage. 

Yelwa Crater is located over 1000 km from the height of Olympus Mons, demonstrating simply how far the damaging landslides travelled from the volcano’s flanks earlier than settling.

Exploring Mars

Mars Categorical has been orbiting the Pink Planet since 2003. It’s imaging Mars’s floor, mapping its minerals, figuring out the composition and circulation of its tenuous ambiance, probing beneath its crust, and exploring how numerous phenomena work together within the martian atmosphere.

The spacecraft’s HRSC, answerable for these pictures, has revealed a lot about Mars’s various floor prior to now 20 years. Its pictures present every part from wind-sculpted ridges and grooves to sinkholes on the flanks of colossal volcanoes to impression craters, tectonic faults, river channels and historic lava swimming pools. The mission has been immensely productive over its lifetime, making a far fuller and extra correct understanding of our planetary neighbour than ever earlier than.

The Mars Categorical Excessive Decision Stereo Digital camera (HRSC) was developed and is operated by the German Aerospace Heart (Deutsches Zentrum für Luft- und Raumfahrt; DLR).