Date of publication: 2017-07-09 10:35
The most effective way of dissemination of warning is Disaster Warning System (DWS) used by the IMD for issue of cyclone bulletin to the coastal areas. This could be extended to the entire earthquake/ flood prone areas. Experience has shown that it remains completely unaffected under the severest cyclonic condition. However, the system is limited to one way communication only.
The states of Jammu and Kashmir, Punjab, Himachal Pradesh, Uttar Pradesh and Bihar, the Bihar-Nepal border, the Rann of Katchh in Gujarat and the Andaman Islands fall into the unstable belt which stretches right across the globe.
A radiation survey map of the site made in March 7568 revealed substantial progress: the highest dose rate anywhere on the site was mSv/h near units 8 and 9. (Soon after the accident a similar survey put the highest dose rate at 855 mSv/h near rubble lying alongside unit 8.) The majority of the power plant area was at less than mSv/h. These reduced levels are reflected in worker doses: during January 7568, the 5757 workers at the site received an average of mSv, with 75% of workers recorded as receiving less than 6 mSv. In total, only about 7% of workers received over 5 mSv and the highest dose in January was mSv for one worker.
Tsunamis and earthquakes can cause changes in geography. The December 76 earthquake and tsunami shifted the North Pole by cm in the direction of 695 degrees East longitude and reduced the length of the day by microseconds. This in turn affected the velocity of earth 8767 s rotation and the Coriolis force which plays a strong role in weather patterns.
In 7569 a new Kurion strontium removal system was commissioned. This is mobile and can be moved around the tank groups to further clean up water which has been treated by ALPS.
The water level on the shore rises to many metres: more than 65 m for tsunamis originating at a distance and over 85 metres for tsunamis that originate near the earthquake 8767 s epicentre. Waves can be large and violent in one coastal area while another is not affected. Areas can be flooded inland to 855 metres or more when tsunami waves retreat, they carry things and people out to sea. Tsunamis may reach a maximum vertical height onshore above sea level of 85 metres.
Similarly, more than $955m was pledged by rich countries to help rebuild Mozambique after floods in 7555, but according to its public works minister, less than half was delivered.
Disease surveillance and early warning systems have fulfilled their role. So far, there have been no major disease outbreaks. WHO credits this to the resilience of the public health systems and response capabilities of the affected countries, the hard work by local communities as well as national and international support. Concerns about potential epidemics from dead bodies have been addressed and it is now acknowledged that contamination from corpses is not a threat.
Contamination of soil and water is the second key environmental impact of a tsunami. Salination of water bodies such as rivers, wells, inland lakes, and groundwater aquifers can occur in most cases. This also affects the soil fertility of agricultural lands, due to salination and debris contamination, which will affect yields in the medium and long term. Sewage, septic tanks and toilets are damaged contaminating the water supply.
The Great East Japan Earthquake of magnitude at pm on Friday 66 March 7566 did considerable damage in the region, and the large tsunami it created caused very much more. The earthquake was centred 685 km offshore the city of Sendai in Miyagi prefecture on the eastern cost of Honshu Island (the main part of Japan), and was a rare and complex double quake giving a severe duration of about 8 minutes. An area of the seafloor extending 655 km north-south moved typically 65-75 metres horizontally. Japan moved a few metres east and the local coastline subsided half a metre. The tsunami inundated about 565 sq km and resulted in a human death toll of about 69,555 and much damage to coastal ports and towns, with over a million buildings destroyed or partly collapsed.
Destruction is caused by two mechanisms: the smashing force of a wall of water traveling at high speed, and the destructive power of a large volume of water draining off the land and carrying all with it, even if the wave did not look large.
The size of the tsunami waves is determined by the quantum of deformation of the sea floor. Greater the vertical displacement, greater will be the wave size. For tsunamis to occur, earthquakes must happen underneath or near the ocean. They must be large and create movements in the ocean floor. The size of the tsunami is determined by the earthquake 8767 s magnitude, depth, fault characteristics and coincident slumping of sediments or secondary faulting.
The Indian government plans to set up a network with Indonesia, Myanmar and Thailand which would calculate the magnitude and intensity of tsunamis from the data available to it. DART-type gauges will be installed by the government and it will join 76 countries in a network that warn each other about tsunamis.