Wednesday, April 11, 2012

Fact File #2 NATURAL DISASTERS

With the huge earthquake that sent tremors(quite literally) today,11/4/2012 ,
and the talks of tsunamis that bring us the memories of Dec 26,04 back,
I decided to post something about natural Disasters that you are unlikely to have heard of before.


1) Let us start of with a relatively common thing,
the tsunami

the name derives from Japanese for harbour waves , and are often refered to as tidal waves which is wrong.
they are oft triggered by earth quakes near or under the sea.
Tsunamis cause damage by two mechanisms: the smashing force of a wall of water travelling 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.


Damage caused by a tsunami

LOL

2)
Limnic eruption
Never heard of it right?

thats probably because this has happened only twice in recorded history

limnic eruption, also referred to as a lake overturn, is a rare type of natural disaster in which  CO2 suddenly erupts from deep lake water, suffocating wildlife, livestock and humans. Such an eruption may also cause tsunamis in the lake as the rising CO2 displaces water. Scientists believe lanslides,volcanic activity, or explosions can trigger such an eruption. Lakes in which such activity occurs may be known as limnically active lakes or exploding lakes. Some features of limnically active lakes include:
  • CO2-saturated incoming water
  • A cool lake bottom indicating an absence of direct volcanic interaction with lake waters
  • An upper and lower thermal layer with differing CO2 saturations
  • Proximity to areas with volcanic activity


For a limnic eruption to occur, the lake must be nearly saturated with gas.
Once the lake is saturated with CO2, it is very unstable. A trigger is all that is needed to set off an eruption.

Once an eruption occurs, a large CO2 cloud forms above the lake and expands to the neighbouring region. Because CO2 is denser than air, it has a tendency to sink to the ground while pushing breathable air up. As a result, life forms that need to breathe oxygen suffocate once the CO2 cloud reaches them, as there is very little oxygen in the cloud. The CO2 can make human bodily fluids very acidic, potentially causingCarbon di oxide poisoning . As victims gasp for air they actually hurt themselves more by inhaling the CO2 gas.
(the thing abt limnic explosion was from wiki,for more details search it on wiki)


3)
Gamma-ray bursts
Gamma-ray bursts (GRBs) are flashes of gamma rays associated with extremely energetic explosions that have been observed in distant galaxies. They are the most luminous electromagetic events known to occur in the universe. Bursts can last from ten milliseconds to several minutes; a typical burst lasts 20–40 seconds. The initial burst is usually followed by a longer-lived "afterglow" emitted at longer wavelengths 



The sources of most GRBs are billions of light years away from EARTH, implying that the explosions are both extremely energetic (a typical burst releases as much energy in a few seconds as the sun will in its entire 10-billion-year lifetime)
All the bursts astronomers have recorded so far have come from distant galaxies and have been harmless to Earth, but if one occurred within our galaxy and were aimed straight at us, the effects could be devastating. Currently orbiting satellites detect an average of about one gamma-ray burst per day.
More Details

4)
1918 flu pandemic The 1918 flu pandemic (the "Spanish flu") was an influenza pandemic, and the first of the two pandemics involving H1N1 influenza virus (the second was the 2009 flu pandemic, an outbreak of swine flu). It was an unusually severe and deadly pandemic that spread across the world. Historical and epidemiological data are inadequate to identify the geographic origin. Most victims were healthy young adults, in contrast to most influenza outbreaks, which predominantly affect juvenile, elderly, or weakened patients. The flu pandemic was implicated in the outbreak ofencephalitis lethargica in the 1920s.
The pandemic lasted from January 1918 to December 1920, spreading even to theArctic and remote Pacific islands. Between 50 and 100 million died, making it one of the deadliest natural disasters in human history. Even using the lower estimate of 50 million people, 3% of the world's population (which was 1.86 billion at the time) died of the disease. Some 500 million, or 27%, were infected.
H1N1 navbox.jpgthe cause

5)
HAIL STORMS
Hail is a form of solid precipitation. It consists of balls or irregular lumps of ice, each of which is referred to as a hail stone. Hail stones generally fall at higher speeds as they grow in size, though complicating factors such as melting, friction with air, wind, and interaction with rain and other hail stones can slow their descent through Earth's atmosphere. Severe weather warnings are issued for hail when the stones reach a damaging size, as it can cause serious damage to man-made structures and, most commonly, farmers' crops.
During the Middle Ages, people in Europe used to ring church bells and fire cannons to try to prevent hail, and the subsequent damage to crops. Updated versions of this approach are available as modern hail cannonsCloud seeding after World War II was done to eliminate the hail threat, particularly across Russia - where it was claimed a 50 to 80 percent reduction in crop damage from hail storms was achieved by deploying silver iodide in clouds using rockets and artillery shells. Their results have not been able to be verified. Hail suppression programs have been undertaken by 15 countries between 1965 and 2005.
But ,to this day, no hail prevention method has been proven to work.




PS
Hope you are all safe and don't get affected by any of these :D
Oh yeah and I also hope that the mayas were wrong




Reactions:

2 answers:

facts 2 and 3 are very nice
keep up the good work

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