Tremors on the Earth Volcanic eruptions, landslides and movement of the Earth’s crust sends tremors across the surface these tremors are called ‘Earthquakes’. They often result in large Kettle damage to property and, on occasions, life in general. About 60 kms below the Earth’s surface tire the focus points for the earthquakes. The surface above the focus point is called the ‘Epicentre’ Like the Volcanic eruptions, most of the earthquakes occur...

Volcanoes Various plates of the Earth’s crust shift, due to the molten rock lying beneath them, this causes them to collide or spread out. This movement forces the molten rock to move upwards and come out on the surface thus forming volcanoes. It is because of this that most volcanoes are located on the edges of the Earth’s crustal plates. The name Volcano is derived from the name of an island...

Rocks and Their Types Fusion of dust particles, under pressure, in outer space formed the first rocks. These rocks then formed most of the planets. Most of the  Earth’s surface is made up of rocks this includes the Mountains, stones, pebbles and the soil which is also made of finer particles of rock. We have rocks which are about 3,900 million years old. Based on their mode of formation, rocks can...

The Changing Surface of the Earth The Earth’s surface is changing all the time, these changes are caused by wind, water and ice and are so gradual that we fail to notice them. Tiny rivulets flowing down from the top of the mountains join with others and are soon turned into fast flowing rivers. These rivulets and rivers carry away with them, rocks and the upper layers of soil, some even...

Creation of the Mountains Elevations on the Earth’s surface have been constantly changing due to the movement of it’s crust. On occasions the crust tends to sink downwards in some places, causing faults, the corresponding area which doesn’t sink is then at a higher elevation. Elsewhere while moving, the Earth’s crust tends to exert pressure sideways thus causing it to crease or form folds. The former result in the formation of...

Waves and Tides   The two most common and regular motions of the oceans are the ‘Tides’ and ‘Waves’. The Moon’s gravitational pull on the Earth causes the level of water in the oceans to rise and fall, thus causing high and low tides. When the Moon is opposite an ocean, the water is pulled upwards thus causing a high tide. This happens on the opposite side of the Earth as...

Oceans and Seas The oceans are vast expanses of water which cover about 71 percent of our planet and separate the continents. Millions of years ago when the Earth cooled from it’s molten state, water vapour in the atmosphere condensed to form water which collected in deep trenches on the surface, thus forming the oceans. Water on the land flowed into them in the shape of rivers, which carried with them...

The Continents Twenty nine percent of the Earth’s surface is land and about 200 million years ago it was a single mass surrounded by the oceans called ‘Pangaea’. In the year 1912 a German meteorologist called Alfred Wegener suggested that this single mass of land was in reality located above large flat pieces of rock. called ‘plates’, which had large cracks m them. With the passage of time, about 130 million...