Sea level below sea level?

Question

The gravitation of Indian Ocean floor is greater than any other oceans in world due to a large concentration of seamounts and mountains chains which causes the ocean surface to cave in, at the lowest point it can be and up to 300 feet "below sea level" in the area of 1,000 miles in diameter. True or False?

Using "Mean Sea Level" by military Flight Surgeons - takes high/low pressure, earth rotation, moon gravitation, wind, water tempurature, currents into consideration, I'm using the word "caved in" loosy it's more like a 'flat spot' from average mean theoretical water surface curvature.
I did not make this up, I know I heard or read about it from some where not too long ago, two main source I can think of are Discovery Chanel and/or National Geographic.

This information ralatively new, any web site that is established prior to 2002 (conservative) will not cover this topic.

Answer 1

It's false, but not for the reason you might think.

Variations in seafloor gravitation certainly do produce variations in the level of the sea surface above them. But the question has the effect backwards.

Higher local seafloor gravitation draws more water into its vicinity, causing local sea level to RISE, not fall. And these local variations can in fact be as much as 300 feet.

Incidentally, the surface levels of the Indian Ocean are neither particularly higher nor lower than other oceans. But its lowest areas are those with no seamounts (the sea floor "plains").

***
I think you've misunderstood me. I'm not saying that the Indian Ocean is not a low spot. I'm saying that you have the cause of the low spot backwards. Surface levels are lower than mean worldwide sea level not because there is a high concentration of seamounts, etc on its floor, but because there are relatively fewer there than elsewhere.

And the links I showed were the explanations for the process of satellite measurement, not the current data. Here's one that includes data through 2005. And it does now appear to show that the Indian Ocean has the lowest mean sea levels in the world.
http://earth.esa.int/brat/html/appli/geodesy/geodesy_en.html

Answer 2

Gravitational pull does not cause isolated depressions in the ocean. However, the level of the sea is not the same all over due to the rotation of the earth. Haven't you heard of locks in Suez and Panama canals where ships are stopped between locks to adjust the difference in sea levels?

Answer 3

False