I suspect the artist spent more than a few seconds looking at the works of Bosch. Review:

When the first expedition descended to the bottom of the Atlantic in a perfected high-pressure diving bell, their speculation ran wild as to the wonders they would encounter in that unknown sea-bottom world. But their wildest dreams did not prepare them for uncovering first, the stones of an ancient civilization, and second, the monstrous body of an inhuman creature that had been sealed beneath the waters for countless eons.

One of the reviewer notes: "The scene in the front is pretty well described in the prologue, while the cool futuristic tower comes into play at the end." Makes me want to read it, just to see how. But then another ewview notes it might be the worst thing the author ever wrote, and quotes thus:

My "potboiler" accusation is exemplified by this type of prose: "How many times had the weaklings of this world fled cowering before the wrath of Ruagh and others of his kind? It was of no comfort to recall and count such occasions. Now he, Ruagh—the unquestioned master of thousands—was himself in flight, before the terrible and not-to-be-withstood anger of blind nature."

So maybe I don't want to read it.