Endogenic and exogenic forces

Endogenic forces uplift relief while exogenic forces wear it down. In exams, link uplift and erosion as a coupled process.

Slow crustal uplift is linked with energy from within Earth. In exams, treat crustal deformation as an endogenic process.

Steep slope, rainfall and weak rock increase erosion. In exams, treat slope, water and rock type as key controls.

Earthquakes and volcanoes are driven by internal energy. In exams, identify processes by their energy source.

Weathering breaks or alters rock in place. In exams, in-situ breakdown is the key sign of weathering.

Exogenic processes work toward gradation or leveling. In exams, link them with lowering highs and filling depressions.

Lava formation is endogenic and river dissection is exogenic. In exams, identify both construction and destruction in mixed events.

Diastrophism involves crustal deformation, while volcanism involves magma. In exams, treat both as endogenic but different in nature.

Gravity drives mass movement and downslope motion. In exams, connect movement on slopes with gravity.

Weathering changes rock in place, while erosion removes material. In exams, removal and transport indicate erosion.

Low erosion and resistant rock preserve relief longer. In exams, connect preservation with resistance and weak exogenic action.

Lava flow can create new surfaces and landforms. In exams, consider volcanic construction as a constructive endogenic process.

Denudation includes wearing down and removal of surface material. In exams, link it with exogenic leveling.

Endogenic energy comes from within, while exogenic energy comes from external sources. In exams, classify by energy source.

A fall in base level can cause rejuvenation and deeper incision. In exams, remember the relation between base level and valley cutting.

Exogenic processes work on existing relief and slopes. In exams, view landform development as interaction between processes.

Mass movement is gravity-based, while river erosion is linked with flowing water. In exams, distinguish by the acting agent.

Water, wind and ice are agents that perform processes like erosion or deposition. In exams, identify agent and process separately.

Faulting and sudden displacement are linked with endogenic tectonic action. In exams, associate faults with internal crustal movement.

Rapid exogenic erosion can dominate slow uplift. In exams, focus on the relative rates of processes.

The direct answer is A, earthquake. A rapid endogenic process is a sudden land-forming or crustal event powered by energy inside Earth. An earthquake occurs when stored tectonic stress is released suddenly, sending vibrations through the crust. Step by step: internal forces move or press rocks; stress accumulates along a weakness or fault; the rocks suddenly slip; energy travels as seismic waves; the ground shakes. Option A is correct because an earthquake is both rapid and endogenic. Option B, soil formation, usually takes a long time through weathering, organic activity, and accumulation, and it is mainly a surface process. Option C, chemical weathering, changes minerals through water, gases, or chemical reactions at or near the surface; it is exogenic and generally slow. Option D, river deposition, happens when a river loses energy and leaves sediment; it is an exogenic surface process and is usually gradual. The question asks for speed and source together: sudden plus internal energy points to an earthquake. Exam cue: earthquake and volcanic eruption are common rapid endogenic examples, whereas weathering, erosion, and deposition are generally exogenic.

A landslide is gravity-driven mass movement on a slope. In exams, rainfall may trigger it, but gravity is the main force.

Isostatic adjustment is related to crustal balance and vertical movement. In exams, link it with endogenic crustal change.

Landform development involves interaction of both types of processes. In exams, avoid one-sided explanations.

Mountain building is endogenic and glacial valley erosion is exogenic. In exams, identify both sequence and process type.