HYDROSPHERE Part 02

HYDROSPHERE  Part 02

CORAL REEFS
•    Coral reefs are important marine ecosystems that are found in clear, shallow, tropical waters around the world. They provide habitat for diverse communities of plants and animals.
•    Coral reefs exists where necessary environmental factors prevail. Major reefs are found around Caribbean and indo-pacific regions.
•    The largest among them is the great Barrier Reef located off the east coast of Australia.
•    Coral Bleaching occurs when poor water quality kills coral, leaving behind a colourless skeleton.

SALINITY LEVELS

The oceanic salinity not only affects the marine organisms and plant community but it also affects the physical properties of the oceans such as temperature, density, pressure, waves and currents etc. The freezing point of ocean water also depends on salinity e.g., more saline water freezes slowly in com¬parison to less saline water.

TIDES

•    The periodical rise and fall of the sea level, once or twice a day, mainly due to the attraction of the sun and the moon, is called a tide.
•    Movement of water caused by meteorological effects (winds and atmospheric pressure changes) are called surges. Surges are not regular like tides.
•    The study of tides is very complex, spatially and temporally, as it has great variations in frequency, magnitude and height.

TYPES OF TIDES

•    The strong gravitational pull exerted by the sun and the moon on the earth’s surface causes the tides.
•    The water of the earth closer to the moon gets pulled under the influence of the moon’s gravitational force and causes high tide.
•    During the full moon and new moon days, the sun, the moon and the earth are in the same line and the tides are highest. These tides are called spring tides.
•    But when the moon is in its first and last quarter, the ocean waters get drawn in diagonally opposite directions by the gravitational pull of sun and earth resulting in low tides. These tides are called neap tides.

HIGHEST TIDES

•    The Bay of Fundy has the highest tides in the world, and those enormous tides alone make that the Bay of Fundy is one of the world’s greatest natural wonders.

•    Tucked into a pocket between the Canadian provinces of New Brunswick and Nova Scotia, the Bay of Fundy is famous for having dramatic differences between its high and low tides.

•    In fact, the tides observed here are tied with Ungava Bay (located farther north) for the largest tides on Earth. Under typical conditions, high tide at the head (the most inland part) of the Bay of Fundy is as much as 17 meters (about 56 feet) higher than low tide.