" Those remember Allah, standing,
sitting, and lying on their sides, and reflect on the creation of the
heavens and the earth:O Lord, you have not created this for nothing.Glory
be to you!So safeguard us from the punishment of fire."
Evoking images of boundless beauty and fierce majesty, the vast bodies of water, surrounding the continents, covers 71 percent of the Earth's surface. Each of the oceans, Pacific, Atlantic, Indian, Arctic, makes a contribution to the entire global system. Some of these contributions can be wholly unique, based on the currents, and the position on the globe. From El Niño to the ring of fire, the effects can be felt in one region or on a global scale.
and volcanic vents are common features on certain zones of the ocean floor.
are active at the present time and, in shallow water,disclose their presence
by blasting steam and rock-debris high above the surface of the sea.Many
others lie at such great depths that the tremendous weight of the water
above them results in high, confining pressure and prevents the formation
and explosive release of steam and gases. Even very large, deepwater eruptions
may not disturb the ocean surface.
The unlimited supply of water surrounding submarine volcanoes can cause them to behave differently from volcanoes on land. Violent, steam-blast eruptions take place when sea water pours into active shallow submarine vents. Lava, erupting onto a shallow sea floor or flowing into the sea from land, may cool so rapidly that it shatters into sand and rubble. The result is the production of huge amounts of fragmental volcanic debris. The famous "black sand" beaches of Hawaii were created virtually instantaneously by the violent interaction between hot lava and sea water. On the other hand, recent observations made from deep-diving submersibles have shown that some submarine eruptions produce flows and other volcanic structures remarkable similar to those formed on land.
the Pacific basin, on the bottom of the sea bed, lie a huge chain of volcanic
arcs and oceanic trenches. The 'Ring of Fire', notorious for frequent
earthquakes and volcanic eruptions, stand for three-fourths of earth's
active and dormant volcanoes, and lie along the margins of the Pacific
Ocean, where the large Pacific plate and other tectonic plates dive beneath
yet other plates.
One of the effects of the undersea earthquakes, submarine volcanoes, or landslides, are the tsunamis wich are often incorrectly called tidal waves, yet they have nothing to do with tides. Tsunamis are enormous ocean waves that travel hundreds of miles at speeds near 500 mph, as fast as commercial jets. Only two or three tsunamis are spawned each year. Seemingly small at sea, the waves gain extraordinary size when they plow ashore, at times towering more than 100 feet high.
Tsunami is born At sea Reaching Island
(put your cursor on the images for explanations)
1. In normal conditions, the trade winds blow towards the west across the tropical Pacific. These winds pile up warm surface water in the west Pacific, so that the sea surface is about 1/2 meter higher at Indonesia than at Ecuador. The sea surface temperature is about 8 degrees C higher in the west, with cool temperatures off South America, due to an upwelling of cold water from deeper levels. This cold water is nutrient-rich, supporting high levels of primary productivity, diverse marine ecosystems, and major fisheries.
2. During El Niño conditions, there is a rise in sea surface temperature and a drastic decline in primary productivity, the latter of which adversely affected higher trophic levels of the food chain, including commercial fisheries in this region. Rainfall follows the warm water eastward, with associated flooding in Peru and drought in Indonesia and Australia. The eastward displacement of the atmospheric heat source overlaying the warmest water results in large changes in the global atmospheric circulation, which in turn force changes in weather in regions far removed from the tropical Pacific.