geomorphological landforms and glacieted landscapes Flashcards
what are the 10 geomorphological landforms
of these 10 what 6 are formed by erosion
of these 10 what 4 are formed by deposition
-aretes
-corries
-hanging valleys
-truncated spurs
-glacial troughs
-roches moutonnes
-till plains
-erratics
-moraines
-drumlins
erosion:
-aretes
-corries
-truncated spurs
-hanging valleys
-glacial troughs
-roches moutonnes
deposition:
-till plains
-drumlins
-erratics
-moraines
how are corries formed
what can be formed in a corrie
how long do corries last, are they affected by erosion
give an example of a corrie
-corries form when snow continues to build up in a depression or nivation hollow, compacting to form a glacier
-the glacier then becomes trapped within the hollow, meaning the only way it can move is through rotational slip
-this then erodes the back wall through plucking and frost shattering, and the hollow is depeend through rotational abrasion
-in a corrie, a tarn can be formed if it is filled with water
-corries last a long time and are relatively unaffected by erosion
-Red tarn, lake district
what is an arete and how is it formed
what can be formed if 3 aretes meet at one point
how long do aretes last
give an example of an arete
-an arete is a knie-edged ridge formed between two corries ) where the 2 steep backwalls meet)
-if 3 aretes meet at one point, a pyramidal peak can be formed
-aretes last a long time
-helvellyn, lake distirct
what is a glacial trough and how are they formed
what happens to the original river that the glacier first moved through
how long do glacial troughs last for
-the u shaped valley formed by a glacier eroding and bulldozing through a v-shaped/river valley
-the glacier has enough energy to erode away a rivers interlocking spurs, leaving smooth but steep truncated spurs on the valley sides
-the river that it originally flowed through will continue to flow but will be called a misfit stream
glacial troughs last a long time
what is a hanging valley
what often forms in hanging valleys
how lng do hanging valleys last
what is the difference between a glacial trough and a hanging valley
-a hanging valley is a smaller u-shaped valley caused by a tirbutary glacier
-the smaller glacier does not have enough energy to erode the valleyfloor, leaving a hanging valley
-waterfalls often form in hanging valleys
-hanging valleys last a long time
-a glacial trough is formed by the main glacier whilst a hanging valley is formed by a tributary glacier, this makes the hanging valley smaller in size and lacking the ability to fully erode valley floor
what is a roches moutonnes
what are its 2 different sides, which side would the glacier be moving (from which side to which)
how is a roches moutonnes formed
how long do they last
-a roches moutonnes is a mound of rock shaped by a glacier flowing over it and eroding it
-lee side and stoss side, the glacier would be flowing from the stoss side to the lee side
-a glacier would hit an obstacle that is too large and hard to pluck, it must move over it
-as the glaier hits the obstacle, it increases friction and pressure which would cause the glacier to melt as the lower ice reaches its pressure melting point
-this film of meltwater allows the glacier to slide over the rock, and smaller rocks would abrade the stoss side
-when the glacier reaches the top of the obstacle, the friction and pressure decreases
-this causes the meltwater to freeze, causing frozen rocks to be plucked from the lee side.
-roches mutonnes last a long time
what is till
how are till plains formed
how long do till plains last
what process can disrupt it
-till is unsorted glacial material formed through erosion and weathering
-till plains form when an ice sheet detaches from the glacier and melts, this causes all of the till on top of and within the glacier to deposit on the valley floor
-till plains a medium/long amount of time
-till plains can be disrupted through periglacial processes and meltwater
what is an erratic
how are erratics formed
how long can they last, why
-an erratic is a large boulder that is of a different rock type compared to the surrounding rock
-it is formed when a boulder is broken off by a glacier through erosion or weathering, it is then transported by a glacier to a new, different location where it is then deposited when the glacier loses energy
-erratics can last a long time, it depends on the size of the errartic, they are too big to be displaced by weathering alone
what is a drumlin
how are they formed
how long and high can drumlins be
what are drumlins usually found in
how long do they last
-a drumlin is a mound of glacial till shaped by the movement of a glacier
-when a glacier hits an obstacle that cannot be eroded, deposition from underneath the glacier builds up behind the obstacle
-the glacier then moves over the large mound, dragging the excess deposition over the other side
-rthe blunt end is the stoss side, the tapered end is the lee side
-drumlins can be 1500m long and 100m high
-drumlins are usually found in swarms
-drumlins las a long time
what are moraines
how many different types of moraines are there
name each moriane and explain how they are formed
how long do moraines last, what can they be displaced by
-morianes are deposits of eroded material that are transported with the glacier
-5
-lateral moraine - material deposited on the sides of a glacier, leaving a ridge when the ice melts
-medial moraine - form when 2 lateral moraines meet in the middle of a glacier and deposut material
-ground moraine - carried under the glacier and abraded between the glacier and the valley floor. the only sorted type of moraine
-recessional moraine - glacial deposits formed at the end of a glacier when its retreating and stays stationary for a sufficient amount of time
-terminal moraine - material deposited at the snout of a glacier on the valley floor
-moraines last a medium amount of time
-they can still be displaced by meltwater during retreat or weathering
