Classic glacial and post glacial landforms of snowdonia

Classic glacial and post glacial landforms of snowdoniaCwm Idwal (CI) is a corrie which is a glacially eroded semi circular steep walled basin, cirques ordinarily contain a lake this is what Llyn Idwal is. The younger Dryas period was when CI was create as a cirque, around 12,000 years ago, in the UK the event was called the Loch Lomond Stidial (The BBC, 2002). mixed landforms that be associated with glacial and post-glacial ar found in this area, with using a base map and Google Maps of the area we were able to determine some landforms ahead going into the field. By doing this, we managed to predict the Ice Flow Direction and where the Moraine Ridges were in the landscape.* Next to the footpath, on adjunct 1 grid reference 360001359004, we potty see an Erratic from the annotation on the map that the erratic is elf same(p). appurtenance 2, haoma 1 shows a field sketch of the erratic and tearing measurements of 7 meters long and 2 meters last. An erratic is a boulder ca rried by glacial ice from the origin usually in a varied bed tremble type on destination (Hug, 1998). * Roche Moutonne landforms Commonly decease in clusters (Bennett and Glasser, 1996, p118). However, this example on the base map in addition 1 is a singular mass at 359009 264009. The mass is 10 meters long and 1.5 meters high as shown in appendix 2 figure 3 of my field sketches. the smooth end faces the direction of flow whilst the otherwise side is steeper (Summerfield, 1993).* * The Degraded Rock Wall with loose shake debris is roughly 200 meters high, this was found in appendix 1 at 359008 264007.Being around 400 meters across. The jolt debris loafer be highlighted gratefully by appendix 2, figure 5, on Google maps you terminatenot see argument debris or astragal very clearly, this is why fieldwork is vital for identification. (Google Maps, 2009)* * The glacially Eroded and Steepened Rock Wall on appendix 1 is set at 358002 264007, is typical of a cirque. The landfor m is located at the heads of deep vales (Summerfield, 1993, p274)* * A Hanging Valley is formed from glaciations, universe eroded by a atrophied glacier the valley sits up above Cwm Valley. In appendix 1 the location is 358002 264008 and finishes around 359008 263001. You can see the layout of the hanging valley in appendix 2, figure 9. A typical feature of a hanging valley is a weeweefall or stream which can be seen advantageously on my field sketch. * * Hummocky Moraine is formed from a high debris concentration its an irregular collection of mounds and enclosed hollows (Bennett and Glasser, 1996, p231). These mounds can be seen clearly in appendix 2, figure 8, the cluster is 80 meters wide of the mark and 115 meters length ways. The amount on CI is two small belts either side of Llyn Idwal in appendix 1 at 358005 264003 and 358003 264004.* * Infilled Lake water parting is dammed by a rock lip, the movement of the ice in the Younger Dryas period created a deep basin (Owen an d Green, 1997). Llyn Idwal is from 50- 305 meters wide and 625 meters long. appurtenance 1 locates the lake basin starting at 358004 359002. The field sketch on appendix 2, figure 7, shows the flat lake basin and the lip in the outlying(prenominal) distance of the sketch.* * Whalebacks are parts of bedrock the ice has moved everyplace and so waste been smoothed and rounded all over erosion. In appendix 1 the whalebacks are located at 360006 264001. They range from one hundred forty-five meters long and 40 meters wide.Post glacial landforms develop after the glaciation period, landforms highlighted in appendix 4 such as extravagant rock wall, forming truncated spurs happen due to weathering. Physical weathering dominates cold climates such as CI. block up thaw happens when temperature is around 0 degrees, water in joints freeze and smash by around 10%, weakening the surrounding rock. Physical weathering affects the volume of glacial and post glacial features on appendix 3, wi th exception to the infilled lake basin. pressure level release from the former ice tacking covering the rock produces sheet joints parallel to the ground surface, therefore encourages further weathering. Hydrolysis affects felspar as the water combines with certain minerals in the rock. When weathered it produces Na, K and Mg ions which are clay minerals.Organic action is produced by the action of animals and plant roots braking up the rock. grow seep through existing cracks as they grow and thicken they accession the pressure on the cracks causing them to fracture and expand. In a unwavering environment, such as CI, the growth rate of vegetation is high. Weathering is influenced by climate, be geology, vegetation cover, relief and aspect.The geology is hard rock, made up of felsic tuff, an igneous rock rich in light coloured minerals such as feldspar and silica (quartz) (Hug, 1998). The rock has an equigranular texture, and is cooled very slowly and is intrinsic, slow cooli ng enables the minerals to be very small and confined. Tiff is a hard volcanic rock composed of compacted volcanic ash. Igneous rocks are more resistant than sedimentary, they are older rocks found in upland areas such as conglutination West Wales. Due to the release of pressure from the glacier melting the rock authentic cracked joints and bedding planes which causes water to enter the rock, therefore the amount of joints increases the weathering. The chemical substance composition of the rock determines the vulnerability of weathering. The granite and feldspar are prone to hydrolysis (Alden, 2006). vegetation cover is important, organic acids from plants and other matter increase chemical weathering on Cwm Idwal. Due to the low vegetation cover , the organic acids released from bacteria and respiration of the plant roots only produce a small increase in the carbon dioxide for chemical weathering.Relief and Aspect is a major part of CI, it is a mountainous area, exposed to rain and uttermost(prenominal) temperatures, the area is vulnerable to physical processes such as freeze thaw. sedateness has more force on steep slopes, so weathered significant is removed quickly, such as a steepened rock wall. Not like the more gentle slopes in CI such as the degraded rock wall with a debris cone which is scree arrive at up. geomorphologic mapping is a brilliant way of accessing an area of by-line that people go too. Photographs from people previously going to the area is a brilliant example of secondary data, comprising of brilliant detail. This can include being able to see the proper image of the slopes and the landforms such as scree slopes and degraded rock walls. In appendix 4 lies the photographs which were taken from the trip. This can be harder to see from celestial photographs as the picture quality is set out the more you zoom in, conversely, you can get a scale for the landforms and obtain out the size. Areas that people are unable to climb are eas ily viewed from aerial photographs therefore has an important part. However, both of these techniques have fixed viewpoints and so acquiring a whole virtual picture of an area forward going is impossible. Field mapping is a longer process which you have to be at the area of study. However, for the viewer it is an in depth abridgment with a virtual picture of the whole area. Problems with this method are that areas that are inaccessible due to not having safety equipment cannot be viewed. This is the one major flaw with this approach, landforms associated with this problem are hanging valleys and v shaped valleys. This is where aerial photographs are beneficial. In conclusion, aerial photographs are congenial to work with for former study of a location however field work is call for to incorporate understanding of the area. Nothing is more prominent than a 3D view of the work area. Additionally, photographs, aerial pictures and Google maps are a necessity when exhausting to unde rstand the location prior to visiting to enable building up a picture and specifying what parts you want to specialise in. Word estimate 1,365ReferencesAlden A. 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