Continental Drift Theory, proposed by Alfred Wegener in 1912, was the first attempt to explain the movement of continents and the present arrangement of continents and ocean basins. It suggested that all continents were once united into a single supercontinent 'Pangaea', surrounded by a vast ocean 'Panthalassa'.

Wegener’s Continental Drift Theory (1912) proposed that the supercontinent Pangaea broke apart about 200 million years ago into Laurasia (north) and Gondwanaland (south), separated by the Tethys Sea. These masses drifted equatorward and westward, forming today’s continents, mountains, and oceans.

Alfred Wegener’s Continental Drift Theory (1912) proposed that continents were once united as Pangaea and later drifted apart. Multiple geological, paleontological, and climatic evidences supported this idea, but lack of a mechanism weakened its acceptance until Plate Tectonics provided the missing link.

Arthur Holmes suggested mantle convection currents as the mechanism behind continental drift. Harry Hess and Robert Dietz later proposed Sea Floor Spreading, showing new crust forms at mid-ocean ridges and old crust subducts at trenches. Together these laid the foundation for Plate Tectonic Theory.

Seafloor spreading was confirmed through geological, geophysical, and paleomagnetic evidence, providing the foundation for Plate Tectonic Theory. The theory explains Earth's lithosphere as divided into plates that move over the asthenosphere, shaping continents, oceans, and mountains.

Earth’s lithosphere is broken into rigid plates that float over the semi-molten asthenosphere. These plates move due to mantle convection currents, slab-pull, and ridge-push, leading to continental drift, earthquakes, volcanism, and mountain building.

Plate margins are the edges of tectonic plates, while plate boundaries are dynamic zones where two plates interact. Depending on movement, boundaries can be convergent (destructive), divergent (constructive), or transform (conservative).

Tectonic plate interactions occur as convergent, divergent, or transform boundaries. These interactions shape Earth's surface, forming mountains, trenches, volcanoes, and rift valleys.

Plate Tectonic Theory is the most widely accepted theory that integrates earlier hypotheses like Continental Drift and Seafloor Spreading. It provides a comprehensive explanation for landform evolution, earthquakes, and volcanism.

An earthquake is the sudden shaking or trembling of the earth’s surface caused by the release of energy from the interior of the Earth. This energy travels in all directions as seismic waves, with the greatest impact at the epicenter.

Earthquakes are measured using instruments such as seismographs and seismometers, and evaluated in terms of magnitude (energy released) and intensity (damage caused). Different scales like Richter Scale and Modified Mercalli Intensity Scale are used for assessment.

Earthquakes are measured using instruments such as seismographs and seismometers, and evaluated in terms of magnitude (energy released) and intensity (damage caused). Different scales like Richter Scale and Modified Mercalli Intensity Scale are used for assessment.

Earthquakes are triggered by both natural geological processes and human activities. Natural causes include volcanicity, faulting, and plate tectonics, while anthropogenic causes involve mining, blasting, drilling, and reservoir-induced seismicity.

Around 90% of earthquakes occur along plate boundaries, concentrated in a few major belts such as the Circum-Pacific (Ring of Fire), Mid-Atlantic, and Mid-Continental belts. Intra-plate earthquakes also occur but are less frequent.

India is divided into seismic zones based on the intensity of earthquakes experienced and the presence of active faults. The Seismic Zonation Map is prepared by the Bureau of Indian Standards (BIS).

Earthquakes cause widespread destruction through landslides, ground deformation, and secondary hazards like tsunamis. Their impact varies from local structural damage to global-scale disasters.

Volcanoes are vents or fissures on Earth's surface through which magma, gases, and ashes erupt. They are directly linked to Earth's internal heat and tectonic processes.

Volcanoes are unevenly distributed across the globe, mostly concentrated along tectonic plate boundaries. About 80% of volcanoes are located at convergent plate boundaries, 15% at divergent boundaries, and the rest occur as intra-plate hotspots.

Volcanic eruptions release gases, fragmented materials (pyroclasts), and molten lava. The type of eruption depends on the opening (fissure or central vent) and the viscosity of the magma.

Central eruptions occur through a vent or mouth and vary from calm, non-explosive outflows to violent explosive eruptions. They are classified into Hawaiian, Strombolian, Vulcanian, Pelean, and Plinian types, depending on lava viscosity, gas content, and eruptive style.

Volcanic activity produces diverse landforms depending on whether magma solidifies on the surface (extrusive) or below the surface (intrusive). Extrusive landforms include cones, craters, and plateaus, while intrusive landforms include batholiths, laccoliths, sills, dykes, and phacoliths.

Intrusive landforms form when magma solidifies beneath the Earth's surface. They cool slowly, producing coarse-grained igneous rocks. These features strongly influence mountain building, mineralization, and landscape evolution.

Volcanic eruptions are powerful natural events that reshape landscapes, influence climate, and affect human life. Their impacts can be both constructive (soil fertility, energy, tourism) and destructive (loss of life, lahars, climatic disruptions).