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.
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.
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 .
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.
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.
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.
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.
