World Geography

Scientists created an X-ray view of the Earth by using satellite data and discovered a jet stream within the earth’s molten core. It is an accelerating band of molten iron circling the North Pole, like the jet stream in the atmosphere. The vast jet stream some 420 kilometres wide has trebled in speed since 2000, and is now circulating westwards, which is three times faster than the speed of liquids in outer core. Significance of the discovery:  Magnetic field: Scientists hold that the accelerating jet is a natural phenomenon that dates back as much as a billion years, and can help us understand the formation of Earth’s magnetic fields that keeps us safe from solar winds. Scientists call this to be like tracking the flow of the river at night based on candles floating. The motion of iron itself cannot be seen, but the motion of flux lobes provides insights into the nature of magnetic field  Earth’s interior: the study of the ...

Desertification is the process by which fertile land becomes desert due to drought, deforestation or inappropirate agriculture. Cause of desertification around the world: Africa : Major reasons for deforestation here is 1) Overgrazing 2)Agricultural activities and 3)Overexploitation of vegetation for domestic use. Examples: Horn of Africa and the Sahel have been affected by huge amount of droughts these year. Europe : Overgrazing and Deforestation are the main reasons for the desertification. Water scarcity and droughts are becoming increasing threats to Europe.  Asia : 1) Overgrazing 2)Deforestation 3)Agricultural activities are constitute causes in a decreasing order. A UNCCD reports show that there are expanding deserts in China, India, Iran, Mongolia and Pakistan, encroaching sand dunes in Syria, steeply eroded mountain slopes of Nepal, and deforested and overgrazed highlands in the Lao People's Democratic Republic. Australia : Overgrazing is the major cause o...

A low pressure system also known as a Depression occurs when the weather is dominated by unstable conditions. Formation: Under a depression air is rising, forming an area of low pressure at the surface. This rising air cools and condenses and helps encourage cloud formation, so the weather is often cloudy and wet. In the Northern Hemisphere winds blow in anticlockwise direction around a depression. Isobars are normally closely spaced around a depressions leading to strong winds. Depressions are often accompanied by fronts. Most depressions have a warm and cold front, more mature depressions may also have an occluded front. Maturity: The warm air rises up above the sinking colder air . A warm area develops between the warm and cold fronts. The mature stage of a depression often occurs over the UK. Occlusion: The cold front travels at speed of 40 to 50 miles per hour, compared to the warm front which travels at only 20 to 30 miles per hou...

Pacific ring of fire is an arc in the Pacific Ocean basin where many earthquakes and volcanic eruptions occur. About three quarters of the world’s dormant volcanoes and active volcanoes are here. There are 452 volcanoes in the ring which is 40,000 km long. About 90% of the world’s earthquakes and 80% of the world’s largest earthquakes occur along the ring of fire. It is a direct result of plate tectonics and the movement and collision of crustal plates. Both Japan and Ecuador are on the seismically active “ring of fire” around the Pacific Ocean Ecuador:- Ecuador forms the boundary between the Nazca and South American tectonic plates. These plates are continuously grinding against each other at a rate of up to 80mm per year. The Nazca plate, which makes up the Pacific Ocean floor in this region,  is being pulled down and under the South American coast. This is the reason for earthquake in the region. Recent earthquake in Ecuador of magnitude-...