Open Your Atlas and Put your thinking cap on before reading these points.

Earth rotates around its axis <tilted at 23 and half degree to perpendicular>and takes 24 hours – responsible for day and night
Earth revolves around the sun in counterclockwise direction from west to east- takes 365 days <which planets revolves east to west>
Revolution of earth on a tilted axis is responsible for seasons <not distance from Sun of ellipse>
This tilt also gives rise to Tropical region <where Sun can reach directly overhead> and polar regions i.e arctic and Antarctic circles <where sun can be above and below horizon for 24hrs at a stretch>

Discuss – Solstices and Equinoxes
Discuss – Why in reality, 6 months day and 6 months night does not occur in polar regions?
Discuss – Why isn’t summer solstice hottest day of the year even though sun is directly overhead?
Discuss – Even though in January we are very slightly closer to the Sun than in June <elliptic orbit>, Northern hemisphere has hotter summers. WHY.

Pakistan – 4, Jammu and Kashmir, Punjab, Rajasthan, Gujarat
China – 5, Jammu and Kashmir, Himachal Pradesh, Uttaranchal, Sikkim, Arunachal Pradesh
Nepal – 5, Bihar, Uttaranchal, UP, Sikkim, West Bengal
Bangladesh – 5, West Bengal, Mizoram, Meghalaya, Tripura, Assam
Bhutan -4, West Bengal, Sikkim, Arunachal Pradesh, Assam
Myanmar -4, Arunachal Pradesh, Nagaland, Manipur, Mizoram
Afghanistan -1, Jammu and Kashmir (Pakistan-occupied area)

9 coastal states plus 2 UTs <Name those 2 UTs>
Total Coastline about 7500 km, mainland coastline about 6000 km<2 islands , Andaman and nicobar in arabian sea, Lakshadweep in BoB>
Gujarat has the longest coastline while Goa the shortest
13 major ports in India <13th is andaman and nicobar port>

Tropical cyclones are thermal in origin, energised by the latent heat of condensation and are thus formed only in tropical region with high sea surface temperature (10-30 degree north and south)
Do not form up to 10 degree from equator as coriolis force which is necessary for winds to rotate is very weak there <coriolis force is zero at equator and increases progressively towards poles>
Temperate cyclones are dynamic in origin, formed due to frontogenesis, confined to temperate region and are more pronounced in northern hemisphere as temperature contrast is more <why>
Tropical cyclones dissipate once they move on land as energy source is not present on land while temperate cyclones can form on land also
As tropical cyclones are more powerful, hence more destructive, brings more rainfall, cover less area and dissipates fast. Opposite is true for temperate.
Very imp. Tropical cyclones moves from east to west <in the zone of trade winds> while temperate move from west to east <in the zone of westerlies>
In the cyclones <all sort of cyclones> wind move in Counterclockwise direction in northern hemisphere and Clockwise in southern <coriolis force causes winds to deflect to the right in the northern hemisphere and to the left in the southern hemisphere>

Discuss – why maximum cyclones on the east coast of India and not on the west coast?
Discuss – Nomenclature of cyclones
Discuss- what are cyclones called in different parts of the world

Savannah sometimes called tropical grassland has grass plus scattered trees which do not form canopy <open canopy>. In contrast, Temperate grasslands have virtually no trees
Savannahs have distinct wet <7 months> and very hot and dry season, receive more rainfall. In contrast, grasslands have more scanty rainfall and more extreme climate
Fire plays a very important role in Savannah, does not allow trees to grow much. It plays much less important role in grasslands
Savannahs have very thin layer of humus, soil is not very rich in nutrients while Grasslands have very thick layer of humus, very fertile soil <hence grain bowls of world>

IAS Prelims tit-bits- Geography part 1

By Dr V