The continental margins forms the part of the seabed that borders the continents. It consist of (1) the continental sheft, (2) the continental slope, and (3) the continental rise.  The continental shelf is submerged...

The bottom of the ocean has feature has varied as those on land. Huge plains spread out across the ocean floor, and long mountain chains rise toward the surface. Volcanoes erupt from ocean bottom, and deep...

Plate tectonics is a theory that explains the origin of most of the major features of the Earth's surface. For example, the theory tells us why most volcanoes occur where they do, why there are high ridges and deep trenches in the oceans, and how mountains form. According to this...

WHAT DID THE CONTINENTS USED TO LOOK LIKE? When the Earth formed, the lighter elements floated to the surface where they cooled to form a crust. Although the first rock were formed over 3,500 years ago they have not stayed the same. They have been changed from forces on the...

WHAT ARE OCEAN TRENCHES? Trenches are the deepest parts of the ocean. Many renches occur in the Pacific Ocean, especialy its in wesstern portion. Most trenches are long, narrow, and deep, 2 to 2.5 miles (3 to 4 km) below the the surrounding sea floor. The greaest depth anywhere in the...

WHAT DEFINES A DAY? For early peoples, the only changes that were truly regular, were the motion of the objects in the sky. The obvious of these changes was the alternate daylight and darkness, caused by the rising  and setting of the sun. Each of these cycles of the sun came...

WHAT IS THE DEPTH OF THE PACIFIC OCEAN? The pacific ocean, the largest and deepest of the world's four oceans, covers more than a third of the earth's surface and contains more than half of its free water. The floor of the pacific ocean, Which has an average depth of around 14,000...

WHAT CAUSES TIDES?OUR WORLD? Tides are the periodic rise and fall of all oceans,  caused by the gravitational pull of the Moon. The moon's pull on the earth draws the ocean water towards the Moon,  making the water form a huge swell. This is known as a high tide. Water...

WHAT ARE MOLLUSCS?  After insects, molluscs form the largest group of animals. Molluscs have soft, muscular bodies, often covered by a protective shell. Some, such as snails, move on a muscular foot , which can be withdrawn into the shell for protection. Other, sea-dwelling...

WHAT IS INSIDE THE STOMACH? If you did not have a stomach you could not eat just two or three main mails each day. You would have to eat lots of tiny ones much more frequently. The stomach is like a stretchy storage bag for food. It expands to hold a whole meal. Then the layer...

 Everything you eat has to be chopped up the broken before the nutrients or goodness in it can be taken into your blood and used by your body cell to make energy. This chopping up and breaking down takes place in your digestive system, or gut. Digestion begins with the...