Tuesday, March 29, 2011

Northrige Earthquaks


The Northridge earthquake occurred on January 17, 1994 Pacific a neighborhood in the city of Los Angeles, California, lasting for about 10–20 seconds. The earthquake had a "strong" moment magnitude of 6.7, but the ground acceleration was one of the highest ever instrumentally recorded in an urban area in North America, measuring 1.7 g At least 33 deaths were attributed to the earthquake, with some estimates ranging much higher, and there were over 8,700 injured. In addition, the earthquake caused an estimated $20 billion in damage, making it one of the costliest natural disasters in U.S. history.



Thursday, March 24, 2011

japan's earthquake/tsunami


The 8.9-magnitude temblor, which was centered near the east coast of Japan, killed hundreds of people, caused the formation of 30-foot walls of water that swept across rice fields, engulfed entire towns, dragged houses onto highways, and tossed cars and boats like toys. Some waves reached six miles inland in Miyagi Prefecture on Japan's east coast.

Tuesday, March 1, 2011

Seismic Waves


Seismic waves are waves of energy that travel through the ground, for example as  an earthquake, explosion, or some other process that imparts low-frequence of energy. Many other natural and anthropogenic sources create low waves commonly referred to as ambient vibrations.Waves are studied by seismologists and geophysicists. Seismic wavefields are measured by a seismograph, geophone, hydrophone in water .

Friday, February 25, 2011

Batholith


A batholith  is a large emplacement of igneous intrusive rock that forms from cooled magma deep in the earth's crust. Batholiths are almost always made mostly of felsic or intermediate rock-types, such as granite, quartz monzonite, or diorite.

Monday, February 14, 2011

Strata vs Shield Volcanoes

 A stratovolcanois also known as a composite volcano, it is a tall conical volcano built up by many layers of hardened lava, tephra, pumice, and volcanic ash. Unlike shield volcanoes stratovolcanoes are characterized by a steep profile and periodic, explosive eruptions is was causes them to build up. The lava that flows from typically cools and hardens before spreading far. The magma forming this lava is often felsic, having high-to-intermediate levels of silica with lesser amounts of less viscous mafic magma. Extensive felsic lava flows are uncommon, but have travelled as far as alomst 9 and a half mils still that big a small town could bw distored.

Friday, February 11, 2011

GULF STREAM

The Gulf Stream, together with its northern extension towards Europe, the North Atlantic Drift, is a powerful, warm, and swift Atlantic ocean current that originates at the tip of Florida, and follows the eastern coastlines of the United States and Newfoundland before crossing the Atlantic Ocean.

Tuesday, February 1, 2011

Plate Tectonics


The story of Plate Tectonics is a fascinating story of continents drifting majestically from place to place breaking apart, colliding, and grinding against each other; of terrestrial mountain ranges rising up like rumples in rugs being pushed together; of oceans opening and closing and undersea mountain chains girdling the planet like seams on a baseball; of violent earthquakes and fiery volcanoes. Plate Tectonics describes the intricate design of a complex, living planet in a state of dynamic flux.

Monday, January 24, 2011

OCEANS

An ocean is a major body of saline water, and a principal component of the hydrosphere. Approximately 75% of the Earth's surface is covered by ocean, a continuous body of water that is customarily divided into several principal oceans and smaller seas.
More than half of this area is over 3,000 metres deep. Average oceanic salinity is around 35 parts per thousand (ppt) (3.5%), and nearly all seawater has a salinity in the range of 30 to 38 ppt. Scientists estimate that 230,000 marine life forms of all types are currently known, but the total could be up to 10 times that number.

Thursday, January 20, 2011

The Water Cycle

The water cycle is also called the hydrologic cycle. Basically, it
involves three steps: water collected in an ocean or other source
evaporates into the air and becomes clouds; the water then gathers together to become heavy enough to fall as rain. The rainwater eventually collects in pools of water which evaporate again. This is a cycle, so it always continues - water never stops moving

Tuesday, January 11, 2011

Early Solar system

The formation and evolution of the Solar System is estimated to have begun 4.568 billion years ago with the gravitational collapse of a small part of a giant molecular cloud.[1]
Most of the collapsing mass collected in the centre, forming the Sun, while the rest flattened into a protoplanetary disk out of which the planets, moons, asteroids, and other small Solar System bodies formed.