செவ்வாய், 23 அக்டோபர், 2018

TO FACE NATURAL DISASTERS LOG IN TO NET AND BE ALERT



LOG IN, TO BE PREPARED
               
N.Nandhivarman

The internet provides a lot of information about natural disasters, and can help people in being forearmed. For that is being forearmed.

Time has come for including disasters management as part of our school curriculum. As disasters have become common, the news coverage is more on the plight of the victims but the thrust area of scientific protections and preparedness in hazards management are ignored.

In one way this could be explained. The question of who will bell the cat is a major stumbling block for predictions. If a scientist forewarns, immediately there are people to counter his views. Instead of expecting government agencies to wake up on time, people must be prepared to rise to the occasion with help of the media. In this field, various earthquake observatories of United States Geological Survey and that of many universities provide information, easily accessible to every one via internet.

Now we can have just observed International Day for Natural Disaster Reduction on OCTOBER 13 while we are surrounded by disasters. United Nations designated the second Wednesday of October every year from December 22, 1989 as International Day for Natural Disaster Reduction and called it as a vehicle to promote a global culture of natural disaster reduction, including disaster prevention, mitigation and preparedness.

EXPLANATION

_ Divergent plate boundaries- where now crust is generated as the plates pull away from each other.

-Convergent   plate boundaries- where crust is consumed in the Earth’s interior as one plate dives under another.

-Transform plate boundaries- where crust is neither produced nor destroyed as plate’s side horizontally past each other.

-Plate boundary zones- Broad belts in which deformation is diffuse and boundaries are not well defined.
                               
Selected prominent hotspots

In pursuance of this, we have to evaluate various measures suggested by United Nations, scientific observatories, various countries and their experiences to evolve right methods for facing natural hazards. It is here the lessons and play tools crafted by the United States Geological survey assume significance. They not only educate people about current earthquakes through animation pictures taken from observatories but also prepare them to be mentally prepared to face calamities.

What we now witness is quakes along the collision lines of continental plates. Exactly what drives plate tectonics is not known. One theory’s that convection within the Earth’s mantle pushes the plates, in much the same way that air heated by your body rises upward and is defected sideways when it reaches the ceiling. Another theory is that gravity is pulling the older, colder, and thus heavier, ocean floor with more force than the newer, lighter sea floor. Whatever drives the movement, plate tectonic activity takes place at four types of boundaries; divergent boundaries, where new crust is formed; convergent boundaries, where crust is consumed; collision boundaries, Where two land masses collide; and transform boundaries, where two plate slide against each other, according to the site www.enchantedlearning.com.

Another truth that researchers are revealing is that the Earth’s longest mountain chain is not the Andes in South America, or the Himalayas in Asia, or even North America’s Rockies. It’s an underwater chain of mountain s 47,000 miles long.

The Chain runs down the middle of the Atlantic Ocean [surfacing at Iceland]. AROUND Africa, through the Indian Ocean, between Australia and Antarctica, and north through the Pacific Ocean, Running along the top of this chain of mountains is a deep crack, called a rift valley. It is here that new ocean floor is continuously created. As the two sides of the mountain move quay from each other, magma swells up from the Earth’s interior. It then solidifies into rock as it is cooled by the sea, creating new ocean floor.

The speed at which new ocean floor is created varies from one location on the ocean ride to another. Between North America and Europe. The rate is about 2.2 inches [(3.6) per year. At the East Pacific rise, which is pushing a plate into the west coast of South America, the rate is 12.6 inches (32.2) per year. With detailed mapping of the ocean floor came many observations that led scientists like Howard Hess and R DEIZAto call the new theory as ‘Sea floor Spreading.’

Among the features that supported the sea-floor spreading hypothesis were mid oceanic ridges. deep sea trenches, island arcs, geomagnetic patterns, and fault patterns. “The deepest waters are found in oceanic trenches, which plunge as deep as oceanic trenches, which plague as deep as 35,000 feet below the ocean surface. These trenches are usually long and narrow, and run parallel to and near the oceans margins. They are often parallel to large continental mountain ranges. Like the mid-oceanic ridges, and that the age of the ocean floor increased in addition, it has been determined that the oldest seafloor often ends in the deep-sea trenches.”

The Western Pacific margin has islands such as the Aleutians, Knurliest, Japan, Ruckus, Philippines, Marianas, Indonesia, Solomon’s, New Hebrides, and the Tonga’s, which can be best described as ‘Island arcs’ and usually situated along deep sea trenches situated on the continental side of the trench. All these and many more new findings which could be read from various web sides provide A to Z information on all natural phenomena along with projections for natural disasters ahead.

On hearing news about natural disasters, students could log onto these web sites and find relevant information to forewarn the people. For instance it must be noted that on the day of Pakistan and Kashmir Quake, there were 177 quakes all over the world., They may be low on the Richter scale, but earth is uneasy and if the quake is in the boundary of Indo-Australian plate as in the recent case one can forewarn the route it may take in due course of time’s


Courtesy: New Indian Express: 15th October 2005

 


  

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