Transcript Landforms
Landforms Landform Types • There are 6 different types of landforms: – – – – – – Mountains Highlands Plateau Hills Plains Valley Classification of Landforms • Each type of landform can be classified by its elevation and its surface relief. • Elevation refers to a landform’s height above sea level. • Surface relief refers to the surface of a landform. Flat landforms having low relief and rough, hilly or jagged landforms having high relief. Isostatic Movement • Isostasy is one form of movement that is responsible for slowly elevating land in the lithosphere and creating new landforms. Diastrophic Processes • Diastrophic processes: the folding, faulting, and plate movements that produce mountain ranges, rift valleys, continents, ocean floors. Mountain Building • Mountains are formed in three ways: – Folding – Faulting – Volcanism Folding • Folding occurs when the Earth is pushed up from either or both sides. • Fold Mountains form as plates slide into each other and the crust is pushed up. Where the crust folds down valleys are formed. Structure of a Fold Mountain • The structure of a fold mountain can be complex. • Simple fold mountains are made of rock layers that rise and fall like waves of water. • The peaks or hills are called anticlines, and the troughs are called synclines. • http://www.brainpop.com/science/e arthsystem/mountains/preview.weml Faulting • Faulting: movement that produces displacement of one rock mass relative to another along a fracture. • Plates either slide past each another, over each other, or away from each other along plate boundaries. • The stresses caused by these actions are called faults. • Faulting occurs when blocks of rock either fracture or pull apart. • Subduction Fault: When an oceanic plate moves under a continental plate. • The volcanic mountains in the Andes have formed directly above subduction faults. • Extension faults: Occur when 2 plates are pulling away from each other. Contour Maps • Geographers use many different mapping techniques to show physical features. • The most common method is contour mapping. • Contour maps show the exact height of the land in measurable terms.