Monday, January 19, 2009


A blizzard is a heavy snowstorm with very cold temperatures, sustained winds of at least 35mph, and visibility of less than 0.25 miles. When a mass of polar air and warm air meet, the polar air pushes the warm air up and settles in the atmosphere where the water vapor forms snow clouds. Then winds and low temperatures combine with the snow to create a blizzard. During blizzards it can be difficult to see or breathe. Blizzards can kill people, cause traffic accidents, and bring cities to a halt.

New York City Street Caught in the Blizzard, 1888

The Central Canada and the Mid Western U.S are often referred to as the "Blizzard Country". People in these countries often experience the dangers of snowstorm. To overcome, these dangers they build houses with steeping roofs, so that the snow does pile up.

The Great Blizzard of 1888, paralysed the Northeastern United States, killing more than 400 people The snowdrifts towered from 15 to 50 feet and more than 200 ships were sunk.

Park Place in Brooklyn

The Schoolhouse Blizzard also known as School Children's Blizzard of Children's Blizzard hit the great plains of the U.S unexpectedly on a warm day, that more than 500 people including school children were killed due to hypothermia.

The Arimistice Day Blizzard or Armistice Day Storm hit the Mid West region of the United States on the 11 November and 12 November, 1940. The temperature dropped sharply, followed by fierce wind, heavy rain, sleet and the snow began to fall. A total of 154 deaths have been recorded in that storm.

The Storm Track of the Arimistice Day Blizzard

Also known as 93 SuperStorm, No-Name Huricane, the White Hurricane, or the Great Blizzard of 1993 is one of the large cyclonic storm that hit the East Coast of North America on March 12-13th, 1993. This storm complex was massive, affecting nearly 26 states of U.S and much of eastern Canada.

A tree falls under the weight of the snow in Ashville, North Carolina

Satellite imagery of the Storm of the Century on March 13, 1993.

Friday, January 9, 2009

Earthquakes are tremors or vibrations caused by the movement beneath the earth surface or by the movement of tectonic plates beneath the earth's surface. The tectonic waves can jolt upon each other, sending a shock of waves.The majority of tectonic earthquakes originate at the ring of fire in depths not exceeding tens of kilometers.

The earthquakes can cause great destruction.The point from the earth where the vibrations originate is called the seismic focus. The term epicenter refers to the point at ground level directly above the seismic focus.The intensity of the earthquake is maximum near the the epicenter.

Although earthquake occurs anywhere, they are more frequent in earthquake zones.The earthquake can cause landslides and volcanic eruptions. A earthquake can trigger tsunami and disturbs the ground water level. It can also change the course of the river causing floods.

The intensity of a earthquake is measured with a instrument called seismograph on the Richter scale. it has a range of 1 to 10. A major earthquake is usually followed by a number of after shocks. Attempts at predicting when and where earthquakes will occur have met with some success in recent years.

Saturday, January 3, 2009


Geysers are jets of hot water that erupt from beneath the ground accompanied by steam. Geyser gets its name from the erupting spring called geysir at Haukadalur, Iceland. The word geysir in Icelandic means 'to gush up'.The formation of geysers requires three factors: water supply, a source of heat and a proper underground circulatory system.

Geysers are not permanent features of land surface. They are formed due to volcanic activities and thousands of them exists world wide. They are about 500 active geysers in Yellowstone National Park at Wyoming, USA. They are also spread all over the island of Iceland. They have been many geysers in New Zealand which have been destroyed due to human activity.
They are two types of geysers- fountain geysers and cone geysers.

Old faithful geyser

Surface water goes down to a depth of 2000m approximately. Due to the extreme heat below the earth's surface, the water turns into steam and pressure increases. This pressure makes the water eject through the vents or cracks on earth's surface.The white stone around the base of the geyser is from dissolved minerals in the water.

Castle Geyser, in Yellowstone National Park.

Although there are many places in the world where hot springs can be found, geysers are extremely rare, largely due to the three specific requirements for their formation.Some geysers stop erupting when the volcanic heat gradually dies down.It may also cease due to earthquake influences and human intervention.

Wednesday, December 31, 2008

Extinct dinosaurs

Dinosaurs are animals that lived on earth several million years ago. They lived during the mesozoic era which is also known the age of dinosaurs. Some are herbivores while others ate flesh of other dinosaurs. But the question is how did they become extinct?

About 65 million years ago, at the end of Cretaceous period, all the dinosaurs had become extinct. There are many theories about the extinction of dinosaurs. It is believed that a massive asteroid may have crashed into the earth. This caused an enormous explosion that formed a huge cloud of dust.This blocked the sun's rays. Because of it the temperature got lowered and the plants died. The herbivores that fed on them also died. The carnivore have fed on there flesh but they may have also perished.

There is also another theory that a massive volcano that erupted, blasting lava into the atmosphere. These theories where developed from the layer of iridium in late cretaceous period. This metal is only present in the core of earth and in asteroids. Hence the theories.

But the disappearance of the dinosaurs gave an opportunity for mammals to became dominant on land and for the birds to rule the air supreme.

Remains of dinosaurs were first discovered in England in the 1820. Then they where discovered in many parts of the world.The name dinosaur was suggested by Richard Owen which means terrible reptiles!!!!

Wednesday, December 24, 2008

What causes Hail?

One of the unusual weather conditions we can experience is a hailstorm. It is quite a thing to see and hear hailstones coming down, sometimes with such force that great damage is done. Animals, and even men, have been killed by hail!

A hailstorm usually occurs during the warm weather and is accompanied in many cases by thunder, lightning and rain. Hail is formed when raindrops freeze while passing through a belt of cold air on their way to earth.

Hailstorm lashes Lismore

Single raindrops form very small hailstones. It is interesting to note when a raindrop falls as a hailstone, it may meet with a strong rising current of air. so, it is carried up again to the level where the raindrops are falling. New drops begin to cling to the hailstone. And as it falls once more through the cold belt, these new drops spread into a layer around it and freeze, and now we have larger hailstones.

Hailstones, in size of a tennis-ball

This rising and falling of the hailstone may be repeated time after time until it has added so many layers that its weight is heavy enough to overcome the force of the rising current of air. Now it falls to the ground.

A field littered with large hailstones right after a summer hailstorm.

Hailstones measuring three or four inches in diameter and weighing as much as a pound are sometimes built up. Snow too freezes around hailstones when they are carried into regions where it is forming. Thus, the hailstones are frequently made up of layers of ice and snow.

Largest Hailstone ever measured (17.8 cm in diameter and a 47.6 cm in circumference)

Hailstorm in Bogota, Colombia

On 20 April 1888 in Moradabad, India, 246 people (along with more than 1,600 sheep and goats) were killed by hailstones, some as big as cricket balls. Hailstones can be a dangerous hazard, especially if they get very large. They can do tremendous damage to property and have even been know to kill cattle!

A larger hailstone has broken the win shield

Friday, December 19, 2008

Stalactites and Stalagmites

A stalactite or dripstone, is a type of speleothem that hangs from the ceiling or wall of limestone caves.

Stalactites come in a variety of forms, some of which have their own classification, such as deflected stalactites. Another much rarer form is the elephant's foot stalactite, which is flat, rather than pointed, on the bottom. An image of these is in the lower table, second image from the left

Stalactites appear in many caves or caverns. The Carlsbad Caverns in New Mexico, is made up of limestone, which is a fairly soft rock that can be dissolved by a weak acid. The acid that dissolves limestone comes from the rainwater. These raindrops combine with the carbondioxide from the air and the soil, and thus changes into carbonic acid.

About one million years ago, the rainwater dripped into the ceiling of the caves, they formed, tiny rings of lime, which crystallized in the ceiling. As time passed, these rings of lime formed a little stone "icicle". It kept on growing. As the time passed, thousands of drops fell on the same spot. The specks of lime formed, looked like a stubby stone candle. The "candle" kept on growing.

The icicle of stone on the ceiling is called a stalactite. The stubby candle on the floor is a stalagmite. Each stalactite and stalagmite grows at a different rate, depending on the wetness of the cave, the temperature of the room, and the thickness of the limestone bed above it.

Stalagmites take on a variety of forms, from tall, spindly "broomsticks" to ornate, multi-tiered towers.

Shape is determined largely by drip rate, ceiling height, cave atmosphere conditions, and the carbonate chemistry of the drip water solution.

Ice Stalagmites

Thursday, December 11, 2008

Mumbai Terror Attack

The Mumbai Terror attack on November 2008 were a series of coordinated terrorists attack across Mumbai, the financial capital of India. The attacks were carried over by the armed men using automated weapons and grenades. The attacks started on 26 November and ended on 29 November, when the Indian security forces, in Operation Black Tornado, brought under control all the attack sites.

Locations of the attack

More than eight attacks took place in the site of South Mumbai: the Chhatrapati Sivaji Terminus, the Oberoi Trident, the TajMahal Palace and Tower, Leopold Cafe, Cama Hospital, the Jewish centre Nariman House, the Metro Cinema, and the lane behind the Times of India Building behind St. Xavier's College. There were also explosions heard around the Mumbai's port area and a taxi blast at Vile Parle.

The attackers traveled by sea from Karachi, Pakistan, across the Arabian Sea to Mumbai. They entered via speed boats that were on board trawlers. The trawlers left Pakistan and stopped at Porbandar, India, before landing in Mumbai.

Some people trapped in the hotels were forced to climb down using curtains or jump to safety.

Mumbai's main railway station was also hit. People fled the huge terminus leaving their luggage when gunmen opened fire.

Security forces managed to free some people from the hotels, but the stand-off continued throughout the day. The attacks were condemned by governments around the world, including the US and UK, whose citizens were among those apparently targeted by the gunmen.

Relatives of victims of the attacks grieved as they waited to pick up bodies from a hospital.

The ten attackers and their home towns in Pakistan have been identified by Mumbai police: Ajmal Amir from Fardikot, Ismail Khan from Dera Ismail Khan, Hafiz Arshad and Babr Imran from Multan, Javed from Okara, Shoaib from Narowal, Nazih and Nasr from Faisalabad, Abdul Rahman from Arifwalla, and Fahad Ullah from Dipalpur Taluka, Ismail Khan is in the North West Frontier Province, the rest of the towns are in Pakistani Punjab.

Ajmal Amir is the only gunman captured alive by police and is currently in Indian custody.