Ocean+Basins

By: Dana M., Marcelaus K. Ocean Basins People used to think that ocean basins were big storage bowls where rivers always dumped their salts. if this was true oceans would always be getting saltier and saltier every year. However this cant be true. its because its taken over 12 million years and the ocean basin isnt that salty. measurments show that the saltinity of the oceans varies from place to place between 30 and 40 ppt.Salts In the Ocean: proportion and dissolved salts have been the same for the past 100 million years. How does salt leave the ocean? the salt leaves the ocean through the rivers and lakes. .media type="custom" key="18922684" align="right" **A journey on the ocean floor** If you could empty the water in the oceans what would you see? Most of the things in the ocean, such as the ocean basins, are much bigger than here on land. There are steep valleys deeper than the Grand Canyon, mountain ranges taller than the Himalayas, and vast plains wider than the Canadian Prairies. The forces that shaped the rivers and lakes are different than the forces that shaped the oceans. There are no rivers, ice, winds, or rain on the bottom of the ocean to erode and carve the rock. The formation of the ocean basins are mostly caused by the movement of the earth tectonic plates. They oceans weren’t always shaped how they are today. The oceans can shrink or get bigger as the tectonic plates move apart and together. Long undersea mountain chains that are called mid-ocean ridges run along the middle of the oceans. These edges are the youngest areas on the sea floor, and they are still being formed by volcanic eruptions. Molten lava runs down from these ridges, and turns into new plate material which pushes tectonic plates further apart. The mid-ocean ridges rise 1000-3000 m above the sea floor and are more than 1000km wide. Big submarine mountain tops are called seamounts. The seamounts are usually older, inactive volcanoes on the edges of mid-ocean ridges. As the plates moved apart the peaks were carried further from the center of the active ridges. Seamounts are mostly found in clusters and are most common in the Pacific ocean. Along the sea floor there are narrow steep-sided canyons called trenches. The biggest trench in the world is called Marianas Trench which extends 11 km below sea level. There is also a band called Marianas Trench which got their name from this trench! Ocean water is not the same as river water. Ocean water has salt water in it and most of it comes off the rocks. Average 1000g of sea water contains 35g of dissolved salt. Some lands bring in different salts and other things. The ocean contains a lot of different minerals found across the ocean.when water evaporatesit leaves salt and other things behind.
 * A Steady State**
 * Salt water **

The first map of the sea floor was made in the 1870's. Sand travels at a speed of about 15 m/s. They know how deep the ocean is by sending sound waves from a boat. today we have detailed pictures that show us what it looks like when your exploring then oceans.we can also record data and use radars, infrared lights, or other means of measuring features on earth.a great advantage of satalites of ships is that it can pick big areas of water like oceans or lakes in all kinds of weather day or night. // Clancy, Christina. Sciencepower8. Toronto: McGraw Hill Ryerson,1999. Print. // //"Google Images." Google Images. Web. 21 May 2012. .//
 * Exploring the ocean **
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