Blizzards

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.

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.

Geysers

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.