Date of publication: 2017-09-05 01:11
Stated simply, 8766 an earthquake is a vehement shake of the earth from natural causes 8767 . Technically an earthquake is a phenomenon of strong vibrations occurring on the ground, consequent to release of large amount of energy within a short period of time because of some disturbance in the earth 8767 s crust or in the upper part of the mantle.
ii. Warning systems that reliably inform the vulnerable populations immediately and in an understandable and culturally appropriate way. The Warning Centre must be able to analyze and forecast the impact of tsunamis on coasts in advance of the waves 8767 arrival and the local, regional, and/or national Disaster Management Organizations (DMOs) must be able to immediately disseminate information of the threat to enable evacuation of all vulnerable communities. The communication methods must be reliable, robust and redundant, and work closely with the mass media and telecommunication providers to accomplish this broadcast.
Aftershocks are earthquakes that often occur during the days and months that follow some larger quake. Aftershocks occur in the same general region as the main shock and are believed to be the result of minor readjustment of stress at place in the fault zones. Generally, major quakes are followed by a larger number of aftershocks, decreasing in frequency with time.
Unlike surface waves that affect only a shallow amount of water, a tsunami stretches all the way to the sea floor, as rises to the land, so does the wave. Arriving at shore, such waves can grow suddenly by dozens of feet. The satellite imaging did not provide a depth for the waves that hit ashore. In deep water, a tsunami can travel at 755 km per hour.
To predict earthquakes one has to first fully understand the underlying dynamics. For example, even though it is known that this intense seismic activity is a result of the north-northeastern movement and under thrusting of the Indian plate, it is not known what fraction of the strain energy is being released by earthquakes along the belt.
X. Tsunami Ready helps community leaders and emergency managers strengthen their local operations. Tsunami Ready communities are better prepared to save lives through better planning, education and awareness. Communities have fewer fatalities and property damage if they plan before a tsunami arrives. No community is tsunami proof, but Tsunami Ready can help minimize loss to your community.
Tropical cyclones are by nature devastating mainly because of their place of birth, namely, the Inter-Tropical Convergence Zone (ITCZ). This is a narrow belt at the equator, where the trade winds of the two hemispheres meet.
The Indian Ocean is not prone to tsunamis. Only two have occurred in this ocean including one on December 76, 7559. India has been a leader in the initiative to develop a reliable tsunami warning system for the ocean. It has decided to set up a sophisticated system for detecting deep sea movements and develop a network with the countries in the Indian Ocean region for sharing information on tsunamis.
While tides are caused by gravitational influences of the moon, sun and the planets, tsunamis are seismic sea waves. That is, they are related to an earthquake- related mechanism of generation. Tsunamis are usually a result of earthquakes, but may be at times caused by landslides or volcanic eruption or, very rarely, a large meteorite impact on the ocean.
Tsunami can be generated when the sea floor abruptly deforms and vertically displaces the overlying water. Tectonic earthquakes are a particular kind of earthquake that are associated with the Earth 8767 s crustal deformation when these earthquakes occur beneath the sea, the water above the deformed area is displaced from its equilibrium position.
Although relatively infrequent, violent volcanic eruptions represent impulsive disturbances, which can displace a great volume of water and generate extremely destructive tsunami waves in the immedi­ ate source area. According to this mechanism, waves may be generated by the sudden displacement of water caused by a volcanic explosion, by a volcano 8767 s slope failure, or more likely by a phreatomagmatic explosion and collapse/engulfment of the volcanic magmatic chambers.
The entire north-eastern region falls in zone V. Besides the North- East, zone V includes parts of Jammu and Kashmir, Himachal Pradesh, Uttarakhand, Rann of Kachch in Gujarat, northern Bihar and the Andaman and Nicobar islands. One of the reasons for this region being prone to earthquake is the presence of the Himalayan Mountains here which have frequent tectonic movements.
Most tsunamis are caused by earthquakes generated in a subduction zone, an area where an oceanic plate is being forced down into the mantle by tectonic plate forces. The friction between the subducting plate and the overriding plate is enormous. This friction prevents a slow and steady rate of subduction and instead the two plates become 8766 stuck 8767 .
The first scale that genuinely calculated a magnitude for a tsunami, rather than an intensity at a particular location was the ML scale proposed by Murty and Loomis based on the potential energy. Difficulties in calculating the potential energy of the tsunami mean that this scale is rarely used. Abe introduced the tsunami magnitude scale M t , calculated from,
Regions with a high tsunami risk typically use tsunami warning systems to warn the population before the wave reaches land. On the west coast of the United States, which is prone to Pacific Ocean tsunami, warning signs indicate evacuation routes. In Japan, the community is well-educated about earthquakes and tsunamis, and along the Japanese shorelines the tsunami warning signs are reminders of the natural hazards together with a network of warning sirens, typically at the top of the cliff of surroundings hills.