Drainage Systems (Drainage Patterns) Drainage systems, also known as river systems, are the patterns formed by the streams, rivers, and lakes in a particular drainage basin. They are governed by tectonic irregularity, nature of underlying rock strata, and the gradient of the land. Based on the correlation … [Read more...]

The landforms created as a result of degradational action (erosion and transportation) or aggradational work (deposition) of running water are called fluvial landforms. Fluvial Erosional Landforms Fluvial Erosional Landforms are landforms created by the erosional activity of rivers. Various aspects of … [Read more...]

Soil Erosion Soil erosion is the loosening and displacement of topsoil from the land due to the action of agents like wind and water. Soil erosion in nature may be a slow process (geological erosion) or a fast process promoted by human activities like overgrazing, deforestation. Weathering and erosion lead … [Read more...]

Tsunami is a Japanese word for “Harbour wave”. A tsunami is a series of very long-wavelength waves in large water bodies like seas or large lakes caused by a major disturbance above or below the water surface or due to the displacement of a large volume of water. They are sometimes referred to as tidal waves because … [Read more...]

Richter Magnitude Scale Charles F. Richter developed the Richter magnitude scale (ML) for measuring the strength (amount of energy released) of earthquakes in 1930s. Because of the various shortcomings of the ML scale, seismologists now use moment magnitude scale (Mw). Both the scales are logarithmic and are … [Read more...]

Earthquakes An earthquake is shaking or trembling of the earth’s surface, caused by the seismic waves or earthquake waves that are generated due to a sudden movement (sudden release of energy) in the earth’s crust (shallow-focus earthquakes) or upper mantle (some shallow-focus and all intermediate and deep-focus … [Read more...]

Rocks are an aggregate of one or more minerals held together by chemical bonds. Feldspar and quartz are the most common minerals found in rocks. The scientific study of rocks is called petrology. Based on the mode of formation three major groups of rocks are defined: igneous, sedimentary, and metamorphic. … [Read more...]

Hotspot Volcanism Hotspot volcanism is a type of volcanism that typically occurs at the interior parts of the lithospheric plates rather than at the zones of convergence and divergence (plate margins). The Iceland Hotspot and Afar Hotspot which are situated at the divergent boundary are exceptions. Hotspot … [Read more...]

Volcanism Types Four types of volcanism can be identified. Exhalative Volcanism (vapour or fumes) Effusive Volcanism (lava outpouring) Explosive Volcanism (violent ejection solid material) Subaqueous Volcanism Exhalative Volcanism (vapour or fumes) This includes the discharge of material in … [Read more...]

Volcanic landforms are divided into extrusive and intrusive landforms based on whether magma cools within the crust or above the crust. Rocks formed by the cooling of magma within the crust are called Plutonic rocks. Rocks formed by the cooling of lava above the surface are called Igneous rocks. In general, … [Read more...]

A volcano is a vent or a fissure in the crust from which lava (molten rock), ash, gases, rock fragments erupt from a magma chamber below the surface. Volcanism is the phenomenon of eruption of molten rock, pyroclastics and volcanic gases to the surface through a vent. Causes of Volcanism There is a huge … [Read more...]

Basics Ridge Mountain ridges refer to mountains which originate as a result of local folding and faulting. Generally, the slope of one side of the ridge is steep in contrast to the moderate slope on the other side (in case of Himalayas, the southern slope is steeper compared to the northern slope). In some … [Read more...]

Fold Mountains Fold mountains are formed when sedimentary rock strata in geosynclines are subjected to compressive forces. They are the loftiest mountains, and they are generally concentrated along continental margins. Geosyncline: a large-scale depression in the earth's crust containing very thick deposits. … [Read more...]

Classification of mountains on the basis of location Continental mountains Oceanic mountains Continental mountains Coastal mountains Inland mountains Coastal mountains the Rockies, the Appalachians, the Alpine mountain chains, the Western Ghats and the Eastern Ghats … [Read more...]

Divergent Boundary In the Seafloor Spreading Theory, we have studied how divergent boundaries below the oceans are responsible for the spreading of the seafloor. In Plate Tectonics, we have learnt about the major and minor lithospheric plates and how these plates moved through the geological past. We have … [Read more...]

Convergent Boundary Along a convergent boundary two lithospheric plates collide against each other. When one of the plates is an oceanic plate, it gets embedded in the softer asthenosphere of the continental plate, and as a result, trenches are formed at the zone of subduction. Convergent Boundary In … [Read more...]

Convergent Boundary Along a convergent boundary two lithospheric plates collide against each other. When one of the plates is an oceanic plate, it gets embedded in the softer asthenosphere of the continental plate, and as a result, trenches are formed at the zone of subduction. Convergent Boundary In … [Read more...]

Convergent Boundary Along a convergent boundary two lithospheric plates collide against each other. When one of the plates is an oceanic plate, it gets embedded in the softer asthenosphere of the continental plate, and as a result, trenches are formed at the zone of subduction. Convergent Boundary In … [Read more...]

Interaction of Tectonic Plates Major geomorphological features such as fold and block mountains, mid-oceanic ridges, trenches, volcanism, earthquakes etc. are a direct consequence of the interaction between various Tectonic Plates (lithospheric plates). There are three ways in which the plates interact with … [Read more...]

Plate Tectonics It was from the continental drift theory, convection current theory and the theory of seafloor spreading, the theory of Plate Tectonics was formulated. In 1967, McKenzie and Parker suggested the theory of plate tectonics. Morgan later outlined the theory in 1968. According to the theory of … [Read more...]