> However, it’s possible that some could pose a risk to mariners. “There’s a point when they’re shallow enough that they’re within the depth range of submarines

> However, it’s possible that some could pose a risk to mariners. “There’s a point when they’re shallow enough that they’re within the depth range of submarines,” says David Clague, a marine geologist at the Monterey Bay Aquarium Research Institute in Moss Landing, Calif., who was not involved in the research. It would be interesting to see what proportion of these 20k deep-sea mountains were actually known to either the US or Soviets as part of their submarine support. Knowing the location of these deep-sea mountains could be very valuable when you are engaged in submarine cat and mouse games with nuclear submarines. My guess is that quite a few were known but classified as a national security matter.