Salt weathering Salts in rocks expand due to thermal action, hydration and crystallisation. Many salts like calcium, sodium, magnesium, potassium and barium have a tendency to expand. Expansion of these salts depends on temperature and their thermal properties.Freezing, Thawing and Frost Wedging Frost weathering occurs due to growth of ice within pores and cracks of rocks during repeated cycles of freezing and melting. This process is most effective at high elevations in
mid-latitudes where freezing and melting is often repeated. Glacial areas are
subject to frost wedging daily. In this process, the rate of freezing is
importantExfoliation can occur due to expansion and contraction
induced by temperature changes. Exfoliation domes and tors result due to
unloading and thermal expansion respectively.

Semi-clustered or fragmented settlements may result
from tendency of clustering in a restricted area of dispersed settlement. More
often such a pattern may also result from segregation or fragmentation of a
large compact village. In this case, one or more sections of the village
society choose or is forced to live a little away from the main cluster or
village. In such cases, generally, the land-owning and dominant community
occupies the central part of the main village, whereas people of lower strata
of society and menial workers settle on the outer flanks of the village. Such
settlements are widespread in the Gujarat plain and some parts of Rajasthan. panna, para, palli, nagla, dhani -hamleted settlement

It was observed that seismographs located at any distance within 105¡ from the epicentre, recorded the arrival of both P and S-waves.

However, the seismographs located beyond 145¡ from epicentre, record the arrival of P-waves, but not that of S-waves. Thus, a zone between 105¡ and 145¡ from epicentre (not from the focus) was identified as the shadow zone for both the types of waves.

The entire zone beyond 105¡ does not receive S-waves. The shadow zone of S-wave is much larger than that of the P-waves.

The shadow zone of P-waves appears as a band around the earth between 105¡ and 145¡ away from the epicentre.

The shadow zone of S-waves is not only larger in extent but it is also a little over 40 per cent of the earth surface.

Hydration is the chemical addition of water. Minerals take up water and expand; this expansion causes an increase in the volume of the material itself or rock

Oxidation means a combination of a mineral with oxygen to form oxides or hydroxides. In the process of oxidation rock breakdown occurs due to the disturbance caused by addition of oxygen.

Red colour of iron upon oxidation turns to brown or yellow. When oxidised minerals are placed in an environment where oxygen is absent, reduction takes place

All natural earthquakes take place in the lithosphere.The point where the energy is released is called the focus
of an earthquake, alternatively, it is called the hypocentre. The energy waves
travelling in different directions reach the surface. The point on the surface, nearest to the focus, is called
epicentre.

Vishakapatanam port is a major port. All other ports
are developed reduce the pressure on main port.Ennore, a newly developed port in Tamil Nadu, has been
constructed 25 km north of Chennai to relieve the pressure at Chennai port.Haldia Port is located 105 km downstream from Kolkata. It
has been constructed to reduce the congestion at Kolkata port.. Jawaharlal Nehru Port at Nhava Sheva was developed as a
satellite port to relieve the pressure at the Mumbai port.

Amphibole

Aluminium, calcium, silica, iron, magnesium are the major
elements of amphiboles. They form 7 per cent of the earth crust. It is in
green or black colour and is used in asbestos industry. Hornblende is another
form of amphiboles.MicaIt comprises of potassium, aluminium, magnesium, iron,
silica etc. It forms 4 per cent of the earth crust. It is commonly found in
igneous and metamorphic rocks. It is used in electrical instruments.

Kashmir or North-western Himalayas comprise a series of ranges such as the Karakoram, Ladakh, Zaskar and Pir Panjal. The north-eastern part of the Kashmir Himalayas is a cold desert, which lies between the Greater Himalayas and the Karakoram ranges.

Refer map

The general elevation of the plateau is from the west to the east. which is also proved by the pattern of the flow of rivers.

The Peninsular India is made up of a series of patland plateaus such as the Hazaribagh plateau, the Palamu plateau, the Ranchi plateau, the Malwa plateau, the Coimbatore plateau and the Karnataka plateau

The latitude of a place on the earth surface is its
distance north or south of the equator, measured along the meridian of that
place as an angle from the centre of the earth Lines joining places with the same latitudes are called
parallels (Parallels of Latitude: The parallels of latitude refer to the
angular distance, in degrees, minutes and seconds of a point north or south of
the Equator. Lines of latitude are often referred to as parallels)If the earth were a perfect sphere, the length of 10 of
latitude (a one degree arc of a meridian) would be a constant value, i.e. 111
km everywhere on the earth.

Physiological density =A total population / net cultivated area

Agricultural density = total agricultural population / net cultivable area

Agricultural population includes cultivators and agricultural labourers and their family members.

The raw materials essential for iron and steel industry are limestone, dolomite, manganese and fire clay. All these raw materials are gross (weight losing), therefore, the best location for the iron and steel plants is near the source of raw materials. In India, there is a crescent shaped region comprising parts of Chhattisgarh, Northern Odisha, Jharkhand and western West Bengal, which is extremely rich in high grade iron ore, good quality coking coal and other supplementing raw materials.

Exfoliation is a result but not a process. Flaking off of more or less curved sheets of shells from over rocks or bedrock results in smooth and rounded surfaces.Decaying plant and animal matter help in the production of humic, carbonic and other acids which enhance decay and solubility of some elements. Plant roots exert a tremendous pressure on the earth materials mechanically breaking them apart.

The clustered rural settlement is a compact or closely built up area of houses. In this type of village the general living area is distinct and separated from the surrounding farms, barns and pastures. The closely built-up area and its intervening streets present some recognisable pattern or geometric shape, such as rectangular, radial, linear, etc. Such settlements are generally found in fertile alluvial plains and in the northeastern states. Sometimes, people live in compact village for security or defence reasons, such as in the Bundelkhand region of central India and in Nagaland. In Rajasthan, scarcity of water has necessitated compact settlement for maximum utilisation of available water resources.

Body waves are generated due to the release of energy
at the focus and move in all directions travelling through the body of the
earth.The body waves interact with the surface rocks and generate
new set of waves called surface waves. These waves move along the surface. The
velocity of waves changes as they travel through materials with different
densities. The denser the material, the higher is the velocity.

Refer map

It is important to have an idea about places which were in the news. The statements are about doklam / Zhoglam plateau

The Imperial Gazetteer of India, representing the 19th century British view of the territory, states that the Dongkya range that separates Sikkim from the Chumbi Valley bifurcates at Mount Gipmochi into two great spurs, one running south-west and the other running south-east. Between these two spurs runs the valley of the Dichul or Jaldhaka river.

the Dongkya range that normally runs in the north Òsouth direction gently curves to east Òwest at the southern end of the Chumbi Valley, running through the Batang La and Sinchela passes and sloping down to the plain. A second ridge to the south, called the Zompelri or Jampheri ridge, runs in parallel to the first ridge, separated by the Doklam or Doka La valley in the middle. At the top of the valley, the two ridges are joined, forming a plateau. The highest points of the plateau are on its western shoulder, between Batang La and Mount Gipmochi, and the plateau slopes down towards the southeast. A stream flows down the Doklam valley collecting the run-off water from the plateau, and joins the Amo Chu river about 15 km to the southeast.

The 89 sq km area between the western shoulder of the plateau and the joining point of the Doklam stream with the Amo Chu river is called Doklam (‘rocky path’)

P-waves vibrate parallel to the direction of the wave.
This exerts pressure on the material in the direction of the propagation. As a
result, it creates density differences in the material leading to stretching
and squeezing of the material.

Overland flow causes sheet erosion. Depending upon
irregularities of the land surface, the overland flow may concentrate into
narrow to wide paths. Because of the sheer friction of the column of flowing
water, minor or major quantities of materials from the surface of the land are
removed in the direction of flow and gradually small and narrow rills will
form. These rills will gradually develop into long and wide gullies; the
gullies will further deepen, widen, lengthen and unite to give rise to a network
of valleys