Land forms:
Landforms are classified into 3 that are Mountains, Plateaus and Plains
Mountains:
- Uplifted portion of earth surface
- Classified into Fold mountains, Block mountains, volcanic mountains, residual or dissected mountains
- Fold mountains - Formed by folding of crystals rocks. E.g., Himalaya, Alps
- Block mountain - Formed when earth crust are raised or lowered during last stage of mountain building
- Volcanic mountains - Formed due to accumulation of volcanic material. E.g., Mt Mauna Loa, Mt Popa
- Residual or dissected mountains - Formed as a result of erosion of plateaus and high plains by various agents of erosion.
- Plateaus are flat table like, upland areas with rough top surface and steep side walls.
- The plateaus which are partially or totally closed by mountain are called "Inter Montane Plateaus". E.g., Tibetian Plateau
- A relatively low lying and flat land surface with least difference between its highest and lowest point is called plain
- Divided into structural, erosional and depositional
- Structural plain - Uplifted of a part of sea floor. E.g., The great plains of USA
- Erosional Plains - Elevated tract of land is worm down to a plain by the process of erosion. E.g., Plain of north Canada
- Depositional plain - Deposition of sediment by river. E.g., Indo-Ganga plain
- Nitrogen - 78%
- Oxygen - 21%
- Argon - 0.93%
- Carbon di oxide - 0.3%
- Green house gases absorb and emit radiation. E.g., carbon di oxide, methane, nitrous oxide
- Lowest layer of atmosphere
- All weather phenomenon takes place in this region
- Tropopause separates troposphere from a nest layer stratosphere
- Temperature in this layer decreases with increase in height ( Normal lapse rate)
- Extending upto 50 km
- Ozone layer is found in this region
- This layer is ideal for flying of aircrafts
- Stratopause separates stratosphere from mesosphere
- Temperature in this region will increase with increase in height (temperature inversion)
- Extending upto 80 km
- Coldest layer of atmosphere
- Temperature decreases with increase in height
- Further divided into Ionosphere and exosphere
- Upto 400km is ionosphere and above is exosphere
- Ionosphere helps in radio communication due to presence of ions.
- Horizontal movement of air is called wind
- Wind blows from high pressure to low pressure
- Divided into Planetary wind and seasonal wind
- Planetary wind - same direction
- seasonal wind - Change direction with season
- Local wind blow in particular local area
- Pacific Ocean - Largest and deepest ocean. Mariana Trench the world's deepest trench is in pacific
- Atlantic Ocean - Longest coast line. Its a busiest ocean which connects western Europe and North Eastern USA. Puerto Rico trench is deepest
- Indian ocean - Sunda Trech is the deepest point
- Arctic ocean - smallest ocean, least saline, shallowest among all. Nansei Trench is deepest.
- Asia is the largest continent, 30% of earth's area and includes 49 countries
- Africa second largest continent having 54 countries
- North America - 3rd largest and have 24 countries
- South America - 4th largest, 13 countries
- Europe - 5th largest, 2nd largest in population, 43 countries
- Australia is a smallest continent
){kind=link}
0 Comments