points by bell-cot 4 days ago | 0 comments
> A huge hole roughly opposite...
Sounds like the Martian mantle is (or was) organized as a single giant convection cell, with the upwelling under the volcanoes and sinking at Hellis Planitia.
Effects of 7km upon the atmosphere seem easily predictable. Ditto the benefits of 7km for exploration - improved aerobraking, drone performance, etc. But not so predictable would be effects on the subsurface.
An obvious downside of 7km would be "better" air cooling of equipment that needs to stay warm during Martian nights.
Also, whatever caused the Noctis Labyrinthus (west side of the valley in the article south east of the volcanoes) is a wild geologic process I don't think I have seen anywhere else. The large valley looks sort of like a rift valley, and erosion canyons are obvious, but Noctis Labyrinthus with it's fragmented plate look is weird, my best guess is a rift valley where three plates are separating, but that is a weak guess.