4.1 And 4.2 Flashcards
How does a valley form
A valley formed by flowing water, or river valley, is usually V-shaped. The exact shape will depend on the characteristics of the stream flowing through it. Rivers with steep gradients, as in mountain ranges, produce steep walls and a bottom. Shallower slopes may produce broader and gentler valleys.
What is glacial erosion
There are two main processes of glacial erosion. The first that we will talk about is plucking, which is defined as the erosion and transport of large chunks of rocks. As a glacier moves over the landscape, water melts below the glacier and seeps into cracks within the underlying bedrock.
What is plucking
When ice freezes over materials and picks it up as it moves.
What is glacial abrasion
the process of scraping a rick away.
What is afforestation
Planting lots of trees
What is deforestation
Cutting down lots of trees.
What is glacial deposition
Glaciers are powerful enough to carry tiny and huge rock debris, and when they drop it, the ice drops it indiscriminantly. Thus, material deposited by ice is unsorted or mixed in size.
What is sedimentary rock
Sedimentary rocks are types of rock that are formed by the deposition and subsequent cementation of that material at the Earth’s surface and within bodies of water. Sedimentation is the collective name for processes that cause mineral or organic particles (detritus) to settle in place.
What is metamorphic rock
A metamorphic rock is a result of a transformation of a pre-existing rock. The original rock is subjected to very high heat and pressure, which cause obvious physical and/or chemical changes. Examples of these rock types include marble, slate, gneiss, schist.
What is igneous rock
Extrusive igneous rocks, also known as volcanic rocks, are formed at the crust’s surface as a result of the partial melting of rocks within the mantle and crust. Extrusive igneous rocks cool and solidify quicker than intrusive igneous rocks. They are formed by the cooling of molten magma on the earth’s surface.
River landscapes
River landscapes change as you go downstream from the source to the mouth. In the upper course of a river, steep gradients lead to rapid-flowing rivers. In the middle course, the river meanders through gentle gradients. In the lower course, the river braids over flat land.
What is a v shaped valley
V-shaped valley. When a river is near its source, it often develops a V-shaped valley as the river erodes down (this is called vertical erosion). At the same time, weathering breaks up material on the valley slopes. Weathered material from the valley sides gets deposited in the river.
What is a U shaped valley
U-shaped valleys, trough valleys or glacial troughs, are formed by the process of glaciation. … They have a characteristic U shape, with steep, straight sides and a flat bottom. Glaciated valleys are formed when a glacier travels across and down a slope, carving the valley by the action of scouring.
Human activity in glacial landforms disadvantages
Farming may harm the environment.
Trees and other vegetation need to be cleared to provide grazing. This vegetation is important for protecting the landscape from erosion and for providing habitats for wildlife.
Human activity on glacial landforms advantages
It has shaped the landscape, helped to build local communities and is an important part of local economies.
