My planet is a 20% larger than the earth, assume a similar atmosphere, but it can be changed to fit the narrative. My ship is not so large as in the original question, a cylinder shape, about a million tons, but this also can be varied to fit the need. Its dimensions are: L952meters x H105m x W105m It is an interstellar vessel designed for travelling through wormholes and therefore was made of incredibly tough material, some sort of graphene / hardened carbon say, so it can withstand the phenomenal pressures and temperatures of wormhole transitions. It was constructed in space for space travel only, and not designed for planet landings. But the ship has to 'crash' land on an uninhabited planet, it can handle re entry and land intact, but I want the impact on the planet to hold some sort of reality check and I think I may have gone too far.
As it lands the ship gouges a scar 100 meters wide, 20m deep and 20 kilometres long, and pushes up banks of displaced soil etc as 'levees' 20 meters above the surrounding land, making the total depth of the gouge 40m. The idea was the gouge crossed a river which flowed into it, bringing water to the crashed ship. The ship also 'bounced/skimmed' a couple of times before making the final grounding.
Assuming soft enough rock and soil, is it possible with the right speed and angle of descent for the ship to have displaced this much material and made these sorts of features and not cause widespread damage to the region, let alone an extinction event on the planet, and have the ship and its passengers survive intact?
Any advise on the physics that I can try to fit to my story I would be very grateful.