landformsvolcanism

Landforms formed by volcanism are surface features created by magma's surface emplacement and eruption. They arise from lava extrusion, fragmentation of magma into tephra, and the partial or total collapse of magma reservoirs. These landforms occur at plate boundaries, in hot-spot environments, and across volcanic fields, yielding a range of shapes from towering mountains to flat lava plains.

Volcanic mountains are the most conspicuous landforms. Stratovolcanoes, or composite volcanoes, grow tall and steep through alternating layers of lava flows and tephra, typical of subduction zones. Shield volcanoes build broad, gently sloping profiles from low-viscosity lava, as seen in intraplate and hotspot settings. Cinder cones are small mounds built from tephra around a vent. Calderas are large depressions produced by eruption-induced collapse, sometimes hosting crater lakes; smaller craters reflect vent activity. Near vents, viscous lava may dome upward to form lava domes, while extensive lava flows can create lava plateaus and lava tubes beneath the surface.

Pyroclastic activity likewise shapes the landscape, producing pumice deposits, tuff rings, and ignimbrite sheets. Volcanic necks are the resistant cores that remain after surrounding rock erodes. Subglacial eruptions can create tuyas, flat-topped formations formed beneath ice. Fissure eruptions along rift zones generate long lava flows and plateaus, and submarine volcanism forms seamounts and volcanic islands. Hydrothermal systems near volcanic centers create hot springs and geysers that modify surrounding terrain.