The continental shelf sometimes extends for hundreds of miles out to sea. Coral reefs ... the aphotic zone all the way to the gigantic abyssal plain. Much of the abyssal plain is between 3,000 ...

The sites were around 1,000 meters deep beneath Sagami Bay, more than 9,000 meters deep along a trench off the Boso Peninsula, and nearly 6,000 meters deep on an abyssal plain located farther ...