Evidence of previous civilizations at bottom of oceans?

[HUBE007]

Some of the lines you're looking at are artifacts of the image processing and scan stitching.

In other words, when joining two pictures together, you don't always get a nice smooth overlap; instead you get regions where there's some distortion.  If you zoom REALLY CLOSE you can see that the texture of the photo changes right next to those lines.

Some are real, and are tectonic features (things that are blurred on the surface because of trees, buildings, etc, etc.  But some are fake.

The best images of the surface of the ocean floor are the bathymetric images.  NOAA has a lovely set of them on this page (you will have to scroll around to find the area https://historicalcharts.noaa.gov/)

Gebco has a lovely set of maps: https://www.gebco.net/data_and_products/printable_maps/

So...what about the wrinkles and folds that run in straight lines?  No, that's not produced by a civilization -- that's the result of stresses and pressure on the rocks.  If you put your hands on either side of a piece of cloth (let's say a towel.  Or a washcloth) and push one of the edges toward the other, you get a lot of straight-line ridges (folds) ... and that's exactly what happens when one tectonic plate pushes or rubs against another.  You get folds and cracks along predictable lines.

So how do we know that's not an ancient civilization?  From the rocks themselves.

Any activity capable of influencing the planet on that large of a scale leaves marks in the rocks.   We, ourselves have now changed the rocks and soil that's forming within our lifetime so that this entire layer of rock is embedded with the ubiquitous microplastic pollution, and it shows up all over the world.

We don't see anything like that.

In addition, civilizations don't just "appear."  They grow from no-civilizations (cultures, tribes, etc.)

Very insightful and thought out response! I will take a look at your links. Thank you for the reply and information!