ocean floor

Frozen methane hydrates are trapped inside subsea permafrost and mixed with sediments across the deep ocean floor.

This is not particularly noticeable in deep sea but as the ocean floor becomes shallower close to land, the wall of water has to rise and is driven onshore by strong winds.

They show the prow of a wooden ship, encrusted with marine life, a few bronze cannons scattered across the sand, and blue-and-white porcelain and gold coins shining on the ocean floor.

She said there were a number of options available if the sub was stuck on the ocean floor, including releasing the legs or waiting for the tide to change.

Investigative hearings will last two weeks, which have so far revealed new images of debris of the Titan submersible on the ocean floor, as well as the crew's final communication: "all good here."