[Robert DeLong]

But then the deepest is supposedly 36,000+ feet or a little over 5 miles, so something is wrong in that story or I am reading that depth incorrectly. Perhaps they mean that the movement was 36,000+ feet under the sea bed,

The Challenger Deep in the Mariana Trench is the deepest known point in Earth's oceans

[spel_grammer_an_punct_polise]

An earthquake can occur underground below the lowest part of the ocean.

That is perhaps why there is confusion.