Landforms on earth and external processes - class-X

Exfoliation involves the removal of the oldest dead skin cells on the skin's outermost surface. Exfoliation is involved in all facials, during microdermabrasion or chemical peels. It is not a chemical weathering.

Regs are vast, stony deserts or plains in arid regions where wind has removed the finer, lighter material, leaving behind a surface of broken rock and gravel.

Abrasion is the mechanical wearing down of rock surfaces by friction caused by materials carried by agents like wind, water, or ice. It is not limited to fluvial erosion, and attrition is the wearing down of the transported particles themselves, not the surface.

Landscapes are sculpted by the combined effects of weathering (breaking down rocks), erosion (removing material), and deposition (accumulating material). All three are fundamental geomorphic processes.

Weathering is the disintegration of rocks in situ. Erosion is the wearing away by agents. Transportation is the movement of material. Deposition is the accumulation of material.

Salinization leads to the accumulation of salts in the soil, which can alter soil structure, making it dense and impermeable, thereby hindering water infiltration and root growth.

Chemical weathering breaks down minerals like feldspar into clay (regolith), while quartz remains resistant. The loosened material is then susceptible to erosion. All statements provided are accurate descriptions of these processes.

Denudation is influenced by a wide range of factors, including the geological structure, the relief of the land, climatic conditions, and human activities that alter the landscape.

Streams can be classified based on their flow duration: perennial (flow all year), intermittent (flow during certain seasons), ephemeral (flow only after rain), and seasonal (flow during specific seasons). All are valid types.

Groundwater is water that occupies the pores and joints in rocks. It is a key agent in weathering, mass movement, and the hydrological cycle, and its availability is heavily dependent on local environmental factors.

Mass movement is the downslope movement of material driven by gravity. It is influenced by slope gradient, material weight, and triggers like water or vibrations. There are many types of mass movement (e.g., creep, slide, flow, fall).

Fluvial erosion is driven by the energy of the water, which is a function of channel gradient, volume, velocity, discharge, and the sediment load it carries to abrade the channel.

Cliffs, caves, and wave-cut platforms are erosional landforms created by wave action. Beaches are depositional landforms formed by the accumulation of sand and shingle.

Continental glaciers, or ice sheets, are massive glaciers that cover vast areas of land. Antarctica and Greenland are the only two regions on Earth that currently host true continental ice sheets.

Stromboli is a volcanic island in Italy that has been in almost continuous eruption for centuries. Its frequent glowing eruptions make it visible from long distances at night, earning it the nickname lighthouse of the Mediterranean.

Milam Glacier is located in the Kumaun region of the Himalayas in the Pithoragarh district of Uttarakhand, India.

A landslide is defined as the movement of a mass of rock, debris, or earth down a slope due to gravity. Earthquakes, cyclones, and floods are distinct natural phenomena.

Cirque - Erosional feature of glacier -  Cliff-like slopes, down which ice and glaciated debris combine and converge, form the three or more higher sides.

Statement (1) is correct: physical weathering is classified into 4 types - thermal, frost, pressure-release, and salt crystal weathering. Statement (2) is false: exfoliation occurs in both dry and humid areas. Statement (3) is correct: frost action (freeze-thaw cycles) is indeed the dominant weathering force in temperate regions. Statement (4) is false: biotic weathering (roots, burrowing animals) can occur independently. Therefore only 1 and 3 are correct.

Chemical weathering involves processes like oxidation. Mechanical weathering includes the action of plant roots. Glacial deposits form till. Deposition by groundwater creates features like stalactites.