Any limestone or dolomitic region showing typical landforms produced by the action of groundwater through the processes of solution and deposition is called Karst topography after the typical topography developed in limestone rocks of Karst region in the Balkans adjacent to Adriatic sea. The karst topography is also characterised by erosional and depositional landforms

Depositional Landforms

Many depositional forms develop within the limestone caves. The chief chemical in limestone is calcium carbonate which is easily soluble in carbonated water (carbon dioxide absorbed rainwater). This calcium carbonate is deposited when the water carrying it in solution evaporates or loses its carbon dioxide as it trickles over rough rock surfaces.

A subcontinent is a big geographical unit that has different geographical features than the rest the continent. The Indian subcontinent exhibits such features in the continent of Asia.

1. It cover 2.4% of the Earth's total land area. It has a long land frontier of about 15200 km and coastline of about 7516.6 km.
2. Its natural frontiers like Himalayas in the North and the Deccan Peninsula in the South provide it a unique identity on the glode.
3. Its longitudinal and latitudinal extent is about 30^o in both directions. The Himalayas separate is from the rest of Asia. It enjoys a unique climate, natural vegetation and culture.

The place inside the earth's crust where the earthquake is generated, is called focus of the earthquake. The point on the earth's surface directly above the focus is called epicentre.

Weathering is the initial step in soil creation. Weathering happens in four different manner: These include chemical weathering, physical weathering, biological weathering and mechanical weathering. The three major ways weathering happens include chemical, physical and mechanical weathering which are explained below.

Physical Weathering

Physical weathering happens when rocks are fragmented into minor fragments while ensuring no alterations in their chemical makeup. The main causes behind physical weathering include spontaneous fluctuations in temperature like too high or too low heat or cold. Variations in would be the causal element of freeze-thaw action and this occurs when water gets collected in the fissures in rocks all through the day and during the temperature drops at night that would be sufficient to freeze water into ice. It is a known fact that almost every substance grows in size when heated and contracts when exposed to low temperature situations. Unlike these cases water converts to ices when the temperature goes below zero and actually expands. The resultant action would result in the expansion of the fissure and thereby the structure of it weathers.

Chemical Weathering

Chemical weathering happens when the chemicals get diluted and dissolved in water and seeps and percolates down the rock surfaces. Chemical weathering happens in areas having high temperatures and enough supply of water alike tropical environments that are humid. While the chemical weathering happens, the composition of minerals alters due to the reaction of chemicals in water or air. This also results in the rock decomposition. Some parts of the rock decomposition are carried away ping through rocks and soil, a procedure called leaching. The water ultimately may carry these materials to rivers and then to the sea. This is the source of the salinity of the oceans. The instances of chemical weathering are oxidation, decay of calcium carbonate, etc.

Mechanical Weathering

Rocks are also fragmented by mechanical force. This procedure is called mechanical weathering. Because of the frequent variations in temperature, rocks begins to contract and expand. This action results in the breakdown of rocks. It is also caused by roots of plants. They are growing through the cracks in the rocks and cracks the rocks apart. Chemical and mechanical weathering work together to break down rocks. Often, mechanical cracks and water seeps into the rock and weathers it chemically.

Latitude and longitude collectively describe a position on the earth's surface. Latitude is north to south, and longitude east to west. Human geography is the study of the effects that humans have on the surface and atmosphere of the earth, and the effect that the surface and atmosphere of the earth have on humans.

6371 Km

A shield volcano has shield-like shape. They are typically very large in area but their cones have a smoother, lower profile than composite volcanoes. They are shaped this way because their lava flows are made of basaltic magma, which has a lower viscosity than the lava from composite volcanoes. This characteristic allows the lava to flow much farther from the caldera and in thinner layers. Mount Kilauea, Hawaii is a well known shield volcano. It has been erupting continuously for over thirty years.

Composite volcanoes are more commonly called stratovolcanoes. They are the stereotypical volcanoes that come to most people's minds when they think of volcanoes. They can be quite steep. They are called composite because their cones are built of layers of tephra, ash, pumice and lava. This is also why they are called stratovolcanoes--another word for “layers” is “strata”. The lava from the volcanoes is felsic and has a high viscosity, so they slow and cool more quickly than the lava flows from shield volcanoes.