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Weathering and erosion; volcanism

Short answer

Weathering is the in-place breakdown of rocks; erosion is the removal and transport of weathered material by agents like water and wind. Volcanism is the process of magma, gases and pyroclasts erupting from the interior, building landforms such as cones and plateaus, with hazards including ashfall, lava flows and lahars.

Define weathering and erosion. Write short notes on volcanism.

Weathering

The in-place breakdown of rocks by physical, chemical and biological processes.

Erosion

The removal and transport of weathered material by agents such as water, wind and ice. Weathering prepares the rock; erosion carries it away.

Volcanism

Volcanism is the process by which molten rock (magma), gases and rock fragments rise from the interior and erupt on the earth's surface (or are intruded into the crust).

  • Causes: pressure release or fault openings at plate margins (subduction zones, mid-ocean ridges) and hot spots.
  • Products: lava, gases, pyroclasts (ash, lapilli, bombs).
  • Types of eruption: central (through a single vent, often explosive) and fissure (usually quiet, along long cracks).
  • Landforms: cones, calderas, lava plateaus (e.g. the Deccan).
  • Hazards: ash fall, lava flows, mud flows (lahars), poisonous gases.

✓ Answer checked by Claude Opus 5.5 (high effort)

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