An earthquake is the result of a sudden release of stored energy in the Earth's outer layer that creates seismic waves. Earthquakes are accordingly measured with a seismometer, generally known as a seismograph. The magnitude of an earthquake is conventionally reported using the Richter scale or a related instant scale. At the Earth's surface, earthquakes may manifest themselves by a trembling or displacement of the ground. Sometimes, they cause tsunamis, which may lead to loss of life and annihilation of property. An earthquake is caused by tectonic plates getting stuck and putting a damage on the ground. The strain becomes so great that rocks give way by breaking and downhill along fault planes. Earthquakes may occur naturally or as a result of human actions. Slighter earthquakes can also be caused by volcanic activity, landslides, mine blasts, and nuclear tests. In its most generic intelligence, the word earthquake is used to describe any seismic event—whether a natural phenomenon or an event caused by humans—that generates seismic effect.
Friday, August 31, 2007
Monday, August 20, 2007
Cloud
A cloud is a visible mass of condensed droplets, frozen crystals suspended in the atmosphere above the surface of the Earth or another earthly body, such as a moon. The branch of meteorology in which exhaust are studied is nephology.
On Earth the condensing matter is typically water vapor, which forms small droplets or ice crystals, typically 0.01 mm in diameter. When surrounded by billions of other droplets or crystals they become observable as clouds. Dense deep clouds exhibit a high reflectance throughout the visible range of wavelengths: they thus appear white, at least from the top. Cloud droplets tend to scatter light professionally, so that the intensity of the solar radiation decreases with depth into the cloud, hence the gray or even sometimes dark exterior of the clouds at their base. Thin clouds may appear to have acquired the color of their environment or background, and clouds illuminated by non-white light, such as through sunrise or sunset, may be colored accordingly. In the near-infrared range, clouds would appear darker because the water that constitutes the cloud droplets muscularly absorbs solar radiation at those wavelengths.
On Earth the condensing matter is typically water vapor, which forms small droplets or ice crystals, typically 0.01 mm in diameter. When surrounded by billions of other droplets or crystals they become observable as clouds. Dense deep clouds exhibit a high reflectance throughout the visible range of wavelengths: they thus appear white, at least from the top. Cloud droplets tend to scatter light professionally, so that the intensity of the solar radiation decreases with depth into the cloud, hence the gray or even sometimes dark exterior of the clouds at their base. Thin clouds may appear to have acquired the color of their environment or background, and clouds illuminated by non-white light, such as through sunrise or sunset, may be colored accordingly. In the near-infrared range, clouds would appear darker because the water that constitutes the cloud droplets muscularly absorbs solar radiation at those wavelengths.
Friday, August 10, 2007
Inca Rope bridge
Inca Rope bridges were simple suspension bridges over canyons and gorges to present access for the Inca Empire. Bridges of this type were suitable for use since the Inca people did not use wheeled transport - traffic was incomplete to pedestrians and livestock. These bridges were an intrinsic part on the Inca road scheme and are an excellent example of Inca innovation in engineering. They were frequently used by Chasqui runners delivering messages throughout the Inca Empire.
The construction of these bridges amounted to a pair of stone anchors on each side of the canyon with immense cables of woven ichu grass linking these two pylons together. Adding to this construction, two additional cables acted as guardrails. The cables which supported the foot-path were unbreakable with plaited branches. This multi-structure system made these bridges strong enough to even carry the Spaniards while riding horses after they indoors. However, these massive bridges were so heavy that they tended to sag in the middle, and this caused them to bend in high winds.
The construction of these bridges amounted to a pair of stone anchors on each side of the canyon with immense cables of woven ichu grass linking these two pylons together. Adding to this construction, two additional cables acted as guardrails. The cables which supported the foot-path were unbreakable with plaited branches. This multi-structure system made these bridges strong enough to even carry the Spaniards while riding horses after they indoors. However, these massive bridges were so heavy that they tended to sag in the middle, and this caused them to bend in high winds.
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