1000 foot tidal wave is an awful lot of water. Is it 10 foot wide?
If the torpedo is detonated by the city then there is not much water to form a tsunami. If it is detonated far enough away to form a respectable tsunami it will not be of this magnitude. There is existing data from nuclear testing to tell us the likely size of the wall of water. Not 1000 feet tall, not nearly.
Look up the 1958 Lituya Bay AK tsunami.
Part of a mountain slid off in a earthquake creating a 1700’ tsunami. Its all about displacement.