1.3 Coastal Landscapes and Processes (Paper 1) Flashcards
<p>What is a<strong>coast</strong>?</p>
<p>A part of land that joins the sea</p>
<p>What causes<strong>waves</strong>to form?</p>
<p>Wind blowing over the sea</p>
<p>What does the<strong>size</strong>and<strong>strength</strong>of waves depend on?</p>
<ul> <li>How strong the wind is</li> <li>How long it blows for</li> <li>How far it travels</li> </ul>
<p>Define<strong>swash</strong></p>
<p>Water rushing up the beach</p>
<p>Define<strong>backwash</strong></p>
<p>Water draining back down the beach</p>
<p>Define<strong>fetch</strong></p>
<p>The distance a wave has travelled</p>
<p>What are<strong>constructive</strong>waves?</p>
<p>Constructive waves are waves that have a very<strong>strong swash</strong>and aweak <strong>backwash</strong></p>
<p>Theybuildup the beach</p>
<p>How do<strong>constructive</strong>waves build beaches?</p>
<p>They deposit material withthe<strong>swash</strong>as the<strong>backwash is weak</strong>and leavesand and pebbles behind</p>
<p>What are<strong>destructive</strong>waves?</p>
<p>Waves that have a<strong>weak swash</strong>and a<strong>strong backwash</strong></p>
<p>They<u>pull pebbles and sand back down the beach</u>as the water retreats</p>
<p>What arethe<strong>features </strong>ofconstructivewaves?</p>
<ul> <li>Low</li> <li>Wave crests far apart</li> <li>Gentle sloping wave front</li> <li>6 - 8 per minute</li> <li>Gentle beach created</li> </ul>
<p>What are thefeatures of<strong>destructive</strong>waves?</p>
<ul><li>Tall</li><li>High frequency</li><li>Break close together</li><li>Up to 15 per minute</li></ul>
<p>What are<strong>marine processes</strong>?</p>
<p>Marine processes are the actions of waves. This includes <b>erosion, transportation & deposition</b></p>
<p>Which<strong>waves</strong>are associated with coastal erosion?</p>
<p>Destructive Waves</p>
<p>Define <strong>weathering</strong></p>
<p>Weathering is the breakdown of rock at or near the surface by the weather</p>
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<p>What is<strong>mechanical</strong>weathering?</p>
<p>Mechanical weathering is caused by physical changes such as changes in temperature, freezing and thawing</p>
<p>Water gets into cracks in rocks, freezes when the temperature drops below 0°C, prising the rock apart. When the water melts, a larger crack develops. Over time, this causes rocks to break apart</p>
<p>What is<strong>chemical</strong>weathering?</p>
<p>The weathering of rocks by chemicals is called chemical weathering. Rainwater is naturally slightly acidic becausecarbon dioxidefrom the air dissolves in it. Minerals in rocks may react with the rainwater, causing the rock to be weathered</p>
<p>Define<strong>erosion</strong></p>
<p>Wearing away of rocks by water, weather or ice</p>
<p>Listthe<strong>4</strong>main types of<strong>erosion</strong></p>
<ul> <li>Hydraulic action</li> <li>Abrasion</li> <li>Attrition</li> <li>Solution</li> </ul>
<p>Define<strong>hydraulic action</strong></p>
<p>Water being forced into cracks in the rock and breaking it up</p>
<p>Define <strong>abrasion</strong></p>
<p>Loose rocks (sediment) are thrown against the cliff by waves. This wears away at the cliff and chips bits of rock off</p>
<p>Define <strong>attrition</strong></p>
<p>Loose sediment that has been knocked off the cliff is swirled around by waves, colliding with other pieces wearing them into smaller smoother pieces</p>
<p>Define <strong>solution</strong></p>
<p>Seawater dissolves material from the rock due to its slight acidity</p>
<p>What is<strong>massmovement</strong>?</p>
<p>When rocks loosened by weathering move down slope under gravity. They can slide or slump</p>
<p>What is<strong>slumping</strong>?</p>
<p>Slumping occurs after long periods of rainfall. The rain seeps through permeable rocks such as sandstone. At the junction where permeable and impermeable rock meet, the saturated soil slumps and slides in a rotational manner along a curved surface</p>
<p>This is common where cliffs are made of clay</p>
<p>What is<strong>sliding</strong>?</p>
<p>Sliding is movement along a flat surface, usually a bedding plane. Large amounts of soil and rock move downslope rapidly and cause a lot of damage</p>
<p>What is <strong>rock fall</strong>?</p>
<p>A type of mass movement where material breaks off the cliff and falls down the slope</p>
<p>How is sediment<strong>transported</strong>along the coastline?</p>
<p>Longshore drift</p>
<p>Describe how<strong>longshore drift</strong>works</p>
<ul>
<li>Waves approach the beach at anangle</li>
<li>As waves break theswashcarriesmaterial up the beachat the same angle</li>
<li>Thebackwash carries material straight backdown the beach under gravity</li>
<li>This causes the material to move along the beach in azig-zagpattern</li>
</ul>
<p>What is<strong>deposition</strong>?</p>
<p>When the sea loses energy, it drops the sand, rock particles and pebbles it has been carrying. This is calleddeposition.</p>
<p><strong>Deposition happens when the swash is stronger than the backwash</strong>and is associated with<strong>constructive </strong>waves</p>
<p>Defne <strong>landform</strong></p>
<p>A feature in the landscape that has been formed by erosion, transportation and/or deposition</p>
<p>What<strong>factors</strong>influence the landforms found along a coastline?</p>
<p><strong>Hard rock</strong> (resistant rock) - does not erode easily - likely to find headlands</p>
<p><strong>Soft rock</strong> (less resistant rock) - erodes easily - more likely to be a bay</p>
<p>List some coastal landforms that result from<strong>erosion</strong></p>
<p>How do<strong>headlands</strong>and<strong>bays</strong>form?</p>
<p>Where coasts are made from alternating bands of hard and soft rocks, destructive waves will erode the less resistant (softer rock) more to form bays and coves. The more resistant (harder) rocks sticks out into the sea to form headlands</p>
<p>Describe how a<strong>wave-cut platform</strong>is formed</p>
<ul>
<li>The sea attacks the base of the cliff forming a wave-cut notch.</li>
<li>The notch increases in size causing the cliff to collapse.</li>
<li>The backwash carries the rubble towards the sea forming a wave-cut platform.</li>
<li>The process repeats and the cliff continues to retreat</li>
</ul>
<p>How docaves, arches, stacks and stumps form?</p>
<ol>
<li>Resistant rock headlands have faults and joints</li>
<li>Abrasion and hydraulic action widens the joints</li>
<li>Waves make the joint wider to form a cave</li>
<li>Waves erode the cave until it cuts through the headland to form an arch</li>
<li>The arch is eroded until the roof collapses leaving a stack</li>
<li>The stack eventually collapses leaving a stump</li>
</ol>
<p>List some coastal landforms that form as a result of<strong>deposition</strong></p>
<ul> <li>Beaches</li> <li>Sand dunes</li> <li>Spits</li> <li>Bars</li> </ul>
<p>How do<strong>beaches</strong>form?</p>
<ol>
<li>The material may come from eroded cliffs or have been moved from a beach somewhere else</li>
<li>Waves transport the material by longshore drift and deposit it</li>
</ol>
<p>What is a<strong>bar</strong>?</p>
<p>A narrow ridge of sand or shingle that grows across a bay</p>