Major landforms of the earth - class-IX

Moraines are ridge-like depositional features of glacial tills. They are long but narrow ridge with height more 30 meters. Moraines are consist of rock materials of heterogeneous shapes and size.

Sea beaches are not the erosional feature of sea waves. They are formed due to the depositional activities of sea waves.

Temperature decreases with an increase in altitude. The reason or this is:

The ground absorbs more radiation from the sun and during night time the ground emits this absorbed radiation to its surroundings. The molecules of air surrounding the land also absorb the emitted radiation from the ground. At locations near sea level where air is most dense the air is very warm at sunset and a few hours after sunset.

At higher altitudes, the air get very rarified i.e. less dense. The less-dense air can seldom absorb the heat emitted by the ground because they are very far apart. The net result is a drop in temperature at higher altitudes.

As a summary, the decrease in temperature is due to the very less heat energy absorbed by the air molecules and the very far distance of air molecules from each other.

Marina Beach in Chennai is the longest natural urban beach in India and one of the longest in the world.

Paleomagnetic data from the Indian subcontinent shows that it was once part of Gondwana and drifted northwards over millions of years to collide with the Eurasian plate. This movement is a well-established fact in plate tectonics.

The Western Ghats are an escarpment formed by the faulting and subsequent subsidence of the western part of the Indian peninsula during the breakup of Gondwanaland. This created the steep western face of the mountains.

The presence of marsupial fossils in Asia provides evidence that these animals, now primarily found in Australia, once inhabited a broader range when the continents were connected. This supports the theory of continental drift and ancient land bridges.

Deccan Traps are Cretaceous-Eocene (3), Western Ghats are Late Cenozoic (1), Aravalli are Pre-cambrian (2), and Narmada-Tapi deposits are Pleistocene (5). Option B correctly maps these geological periods to the features.

The Hemispheres of the Earth in geography and cartography refer to any division of the globe into two hemispheres. The most common such divisions are by latitudinal or longitudinal markers:

North-South

Northern Hemisphere, the half that is north of the equator

Southern Hemisphere, the half that lies south of the equator,

East-West

Eastern Hemisphere, the half that lies east of the prime meridian and west of the 180th meridian

Western Hemisphere, the half that lies west of the prime meridian and east of the 180th meridian

Gondwana land:.Gondwana, also called Gondwanaland, ancient supercontinent that incorporated present-day South America, Africa, Arabia, Madagascar, India, Australia, and Antarctica.

River $\rightarrow$ landform formed is Canyon

• Mountains are the projections from the earth's surface often having a conical peak. Approximately 24% of the land area are covered by mountains in the world. Thus option C ie 20% is the nearest correct option.

Moraines are ridge-like depositional features of glacial tills. They are long but narrow ridge with height more than 30m.  

True,

True,

False,

• The Maharashtra Plateau is mostly made up of basalt rocks of igneous origin. 
  
• The Basalt layers are almost horizontal and this gives an appearance of a step like structure to the entire landscape.
  

The Loess Plateau in China contains the most extensive and thickest deposits of loess in the world, formed by wind-blown silt.

True,