Now if we compare Mars to Earth 200 million years ago, we find in both planets the lowlands on one side and the highlands on the other side. Land chunks on Earth have changed position, but on Mars they remained in the same place where they were initially! The main difference between the two planets is water.
Based on what is seen on Mars and the other inner planets, it is very likely the earth's lowland was flat in the beginning, without ridges and trenches. But just like winds and rain change the surface features of the continental crust, the sea water also changes the surface features of the oceanic crust.
Mid Atlantic Ocean Ridge
Gases released from the earth's interior created clouds in the sky, which have produced rain that put weight on ocean floor.
This shift of energy, from the interior of the earth to the surface of the earth, must have caused a problem for the Earth stability.
The earth adjusted itself with the new situation by introducing ocean ridges and trenches. Expanding at the ridges and shrinking at the trenches.
The cracked solid, basaltic, layer of the Earth allowed ridges and trenches to form.
The only difference between the Earth and the other planets is water. The water has played a major role in dividing and shaping the oceanic crust.
At ocean ridges, magma rises from inside the mantle and builds new ocean floor. At ocean trenches, parts of the ocean floor fall down inside the mantle. This process causes parts of the land to spread away at ocean ridges, and other parts to come closer to each other at ocean trenches.
When ocean basins were filled with a considerable amount of water, the Earth tried to balance this water on its surface. It is like putting a weight on one side of a ball, and you see the air is being pushed to other sides.
In the beginning, the Atlantic Ocean was very narrow, while the Pacific was very big. Most of the weight was on the Pacific.
It seems that the Pacific Ocean is prevented from spreading further by the mountains that are found on the edges of the ocean. The presence of volcanoes along these mountains, on the so-called Ring of Fire, is an indication of lots of activities going on inside the mantle under these areas.
The Ring of Fire, which is a set of volcanoes located on the edges of the
Pacific Ocean, contains over 450 volcanoes. Nearly 90% of the world's major
earthquakes occur along the Ring of Fire. Most ocean trenches are found at the
edges of the Pacific Ocean.
With the exception of sandstone mountains, all rocky mountains have their bases connected directly to the basaltic layer, as we will in the next section.
Whenever the seafloor of the Pacific tries to spread farther, it hits mountains, or the basaltic layer that is connected to these mountains, and that causes earthquakes almost everyday. But these earthquakes that occur on daily basis are considered normal, and usually they do not cause any damages.
On the other hand, the Atlantic Ocean is able to spread, because the spreading force there seems to be stronger! Maybe because the Pacific is carrying a lot of weight on its surface and it has to push against mountains, whereas the Atlantic does not have these obstacles.
At ocean trenches, parts of the ocean floor are melted and fallen down inside the mantle. The mantle compensate for these fallen parts at the ridges in other places. The other places can be anywhere, and not limited to the Atlantic Ocean only. This process causes some places to expand at the ridges, and other places to shrink at the trenches.
The presence of ridges and trenches in oceans led to the development of a theory called Seafloor Spreading. This theory doesn't seem to be correct, because the shrinking ratio at ocean trenches is not the same as the spreading ratio at ocean ridges.
The scientific terms introduced by the Seafloor Spreading theory, such as Lithosphere and Asthenosphere, are theoretical. There is no physical evidence to support their existence.
After countless changes in the Earth structure, the Earth now is shrinking!
QUOTE: "Sea level is
rising — and at an accelerating rate — especially along the U.S. East Coast and
Gulf of Mexico -- Global average sea level rose roughly eight inches from 1880 -
The quote above attributes the increase in sea level to the rise in atmospheric temperature.
Another explanation is that the earth is still adjusting itself since the time of ocean floor formation, millions of years ago. The ocean floor is shrinking at the trenches at a higher rate than spreading at the ridges. Whenever any ocean basin shrinks, the sea level rises. This means that the overall size of the earth is getting smaller very slightly eve ry year.