How do we know what the deepest point of the ocean is, if we’ve only explored like 5%

Question

How do we know what the deepest point of the ocean is, if we’ve only explored like 5%

In: 3

Answer 1

Sonar maps the ocean. We know where it’s deep, how deep it is and can make a model of it.

What we haven’t done is actually been able to go down there. It’s vast, massive and the pressure of even some deep parts, like around the Titanic will be too much for us to take.

Add in the fact that most of the ocean is just…barrren, that there’s nothing *too* explore and that’s why we’ve only physically explored so little.

Answer 2

You can bounce soundwaves off the ocean floor and measure how long they take to come back. You don’t actually have to go down there to know the depth.

Answer 3

Sonar mapping of the ocean floor is reasonably complete, even though humans have not actually explored more than a small fraction of it.