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Along the Seashore

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Along the seashore 8ljkiXc`X`jk_\nfic[Ëjj`ok_cXi^\jk ZflekipXe[`jjliifle[\[Ypj\X% @k_XjXmXjkZfXjkc`e\Çjfd\*.''' b`cfd\ki\j%8cfe^`kXi\dfi\k_Xe((''' Y\XZ_\jXe[XeldY\if]jklee`e^ eXkliXc]\Xkli\j#jlZ_XjM`Zkfi`XËjKn\cm\ 8gfjkc\jXe[N\jk\ie8ljkiXc`XËj E`e^XcffI\\]%Knffk_\ij#k_\>i\Xk 9Xii`\iI\\]Xe[=iXj\i@jcXe[#Xi\ Nfic[?\i`kX^\8i\Xj% Dfjkf]8ljkiXc`XËjgfglcXk`fec`m\j Zcfj\kfk_\ZfXjkc`e\#gXik`ZlcXicp`ek_\ \XjkXe[jflk_$\Xjk%Fecp(,g\iZ\ekc`m\j dfi\k_XeXe_fliËj[i`m\]ifdk_\j\X% K_\mXip`e^Zc`dXk`ZZfe[`k`fejXe[ \em`ifed\ekjf]8ljkiXc`XËjZfXjkc`e\Xccfn `kkfjlggfikXi`Z_[`m\ij`kpf]jg\Z`\j% @edfi\i\Z\ek[\ZX[\j#jfd\f]k_\j\# Xe[jfd\]iX^`c\ZfXjkXc\em`ifed\ekj# _Xm\Y\\e`eZi\Xj`e^cpk_i\Xk\e\[Yp gfcclk`fe#liYXe[\m\cfgd\ekXe[ kfli`jd% ( 9iX`ejkfidknfZcXjjc`jkj1 X eXkliXcZfXjkXc]\Xkli\jXe[ Y _ldXeXZk`m`k`\jfi[\m\cfgd\ekj kpg`ZXccp]fle[Xcfe^ZfXjkc`e\j% ) K_\cXi^\`dX^\fek_\c\]k`jXj\Zk`fe f]k_\Kn\cm\8gfjkc\j% X N_p[fpflk_`ebk_`jd`^_kY\ • How coastlines are formed jlZ_XgfglcXikfli`jkXkkiXZk`fe6 • In what ways people use coastal environments Y ?fnZflc[kfli`jdgfk\ek`Xccp and some of the effects of this use X]]\Zkk_`jeXkliXc\em`ifed\ek6 • Why pollution is causing serious problems for many * N_Xkjfikjf]gi\jjli\j[fpflk_`eb Australian coastlines _ldXeXZk`m`kpXe[[\m\cfgd\ek • How coastlines can be managed to balance competing d`^_kY\gcXZ`e^fek_\jki\kZ_f] demands in a sustainable way ZfXjkc`e\`ek_\jdXcc\i`dX^\6<ogcX`e% 9eWijWbbWdZ\ehci BOUT 85 PER CENT of Australia’s population lives in coastal towns and cities (more A than 25 per cent within three kilometres of the coast). This means that beaches and other coastal landforms are familiar sights for most people. Most of the coastal features we see today were formed in the last 6000 years, after the sea reached its present level. Coastal landforms are formed by A number of different natural sediment-carrying rivers, glaciers two main processes — erosion forces act together to produce or active volcanoes can also and deposition. Some of the coastal landforms. For example, be shaped (that is, built up or landforms resulting from erosion some coastlines, such as those destroyed) by the natural processes are cliffs, rocky platforms, of western South America, lie of these features. headlands, caves, blowholes, stacks adjacent to the boundary of Most typically, though, coastal and arches. In places sheltered tectonic plates, and may be landforms are shaped by the inter- from strong winds and wave infl uenced by movement in the action of waves and wind. More attack, sediments are deposited bedrock as plates move against detail on how this happens — how to form features such as beaches, or pull away from each other. waves build and destroy coastlines spits, dunes, estuaries and lagoons. Other coastlines close to — is provided on pages 4–8. :fXjkXccXe[]fidj Waves are refracted (bent towards) a Over time, the caves Erosion between low and high headland and release energy either side of will erode on either tides undercuts rocks and a rocky Dune blowouts occur when it. Caves will be formed where weak rocks side of a headland and platform develops. This undercut high winds blow the sand long are eroded on each side of a headland. join to form an arch. section eventually becomes weak distances over the land. and collapses, creating a cliff. Estuaries are the parts of a river that are tidal and occur at the sea. They catch mud, sand Further erosion of the and nutrients. rock supporting the arch A lagoon is formed will cause it to collapse, when a sandbar begins leaving a stack. to develop, eventually closing an estuary. Beaches are formed when material is brought to the shore by waves. The material can be sand, stones or pebbles. Dunes are formed when sand on a beach is stabilised by vegetation. ( >kcWd_j_[i7b_l[=[e]hWf^o( Cpi`ZXccXe[]fidj worksheet 1 ?\X[cXe[ÇXZfXjkXccXe[]fidY\`e^Z_Xe^\[Yp\ifj`fe REMEMBER 1 N_XkXi\k_\knfdX`egifZ\jj\j Ypn_`Z_ZfXjkXccXe[]fidjXi\ ]fid\[6<ogcX`e\XZ_f]k_\j\`e pflifnenfi[j% 2 N_Xk_Xgg\ejkfk_\dXk\i`Xc k_Xk`j\if[\[feXZfXjkc`e\Xe[ ]Xccj`ekfk_\j\X6 3 @[\ek`]pk_\]fccfn`e^ jkXk\d\ekjXjkil\fi]Xcj\% I\ni`k\k_\]Xcj\fe\jkfdXb\ k_\dkil\% Headlands are made of softer rock than the surrounding landscape. T/F Rocky platforms are usually submerged during low tide. T/F Caves form in the weakest part of a headland. T/F Beaches are an example of a deposition feature. T/F I`m\i\jklXip A spit is formed when a sandbar closes an estuary. T/F ÇXZfXjkXccXe[]fid Zi\Xk\[Yp[\gfj`k`fe Estuaries trap nutrient-rich sediments. T/F Longshore drift moves sand and other THINK material along a beach. If this drift occurs mainly in one direction, sand may extend 4 N_`Z_ZfXjkXc]\Xkli\j`ek_\ along the coastline forming a spit. `ccljkiXk`fe[fpflk_`ebXi\ Y\`e^1 X Yl`cklg6 Y [\jkifp\[`%\%nfie[fne fi\if[\[ 6 Aljk`]ppfliZ_f`Z\j% 5 N_p[fjkXZbjgifm`[\\m`[\eZ\ k_Xkk_\ZfXjkc`e\nXjfeZ\ ]lik_\iflkkfj\X6 6 :_ffj\knf]\Xkli\j&cXe[]fidj A spit can sometimes join two land areas. This is called a tombolo. `ek_\`ccljkiXk`fe%EXd\k_\d Xe[jb\kZ_k_\`igfk\ek`Xc]lkli\ Xgg\XiXeZ\%8eefkXk\pfli jb\kZ_#c`jk`e^i\Xjfejkfaljk`]p pfligi\[`Zk`fe% If caves develop in places exposed to the sea and INQUIRE waves, water rushes in and 7 :_ffj\fe\ZfXjkXccXe[]fid can cause pressure to build at the back of the cave. If a k_Xk`ek\i\jkjpfl%Ni`k\Ôm\ section of rock in the roof hl\jk`fejpflnflc[c`b\ of the cave is weak, part of Xejn\i\[XYflk`kk_XkXi\efk the roof may collapse and a Xci\X[pXejn\i\[`ek_`jjgi\X[% is formed. blowhole JnXgpflihl\jk`fejn`k_X gXike\i%Lj\k_\@ek\ie\kXe[ fk_\ii\]\i\eZ\jfliZ\jkfj\\ _fndXeppflZXeXejn\i% I CAN: appreciate how key parts of a coastal system are formed Headlands are formed when coastal draw and describe how coastlines rocks are very hard and resist erosion from the waves. Softer can change over time rocks either side of the headland are investigate, in more detail, a B[Whd_d] eroded and transported elsewhere. selected coastal landform. ) 9eWijWbioij[ci >emYeWijiWh[\ehc[Z OASTS, LIKE all natural systems, are constantly experiencing change. While some C coastal features, such as stacks, are being eroded and breaking down, others, such as beaches, may be building up. Over time, a natural balance is preserved between the processes of erosion and deposition. Erosion is the wearing away of the Destructive and When storms occur and Earth’s surface by agents such as waves are large, more material wind and water. Wind and waves constructive waves is carried away in the backwash create the energy that erodes the Waves carry sand and other to deep water. These are called rocks along coastlines. You will be material on and off the shore. destructive waves. When the aware of this energy if you have When a wave breaks, the water waves are small and contain less ever been dumped by a large wave! from it runs up the beach. This is energy, sand and other materials Waves are constantly striking called the swash. The movement are more likely to be carried up against a coastline. When the of water back down the beach to in the swash and laid down as weather is windy, the waves are the sea is called the backwash. deposits on the beach. These larger and more powerful. As the You may have observed the swash are called constructive waves. waves hit the coastline, the energy and backwash moving sand, shells, The fi rst diagram on the left on in them is used to erode rocks seaweed and other material up and the next page shows how waves and move sand, pebbles and other down a beach. bring material to a beach. material. Some rocks are more resistant to erosion than others and will not wear away as quickly. These differences can result in a variety of coastlines and coastal features. Direction of JnXj_Çk_\dfm\d\ekf]nXk\i `jj_`]k`e^jXe[lgk_\Y\XZ_% water movement 9XZbnXj_Çk_\dfm\d\ekf]nXk\i YXZbkfk_\j\X`jj_`]k`e^jXe[Xe[ j\Xn\\[[fnek_\Y\XZ_% Direction of water movement * >kcWd_j_[i7b_l[=[e]hWf^o( :fXjkXcgifZ\jj\j worksheet 2 Longshore drift The end result of this is that material is moved along Sand and other material can be carried along a shore the beach. This movement is called longshore drift as well as up and down it. The direction of the and is shown in the middle diagram below. prevailing winds means that waves usually move Longshore drift can be seasonal. This means towards the shore at an angle. The material is washed its direction can change from season to season, up the shore in the swash at the same angle as the depending on the direction from which the wind is wave whereas the backwash moves straight down the blowing. An example of this is shown in the diagram beach (under the natural infl uence of gravity). below right. 0 250 500 m Black Wave direction Longshore Rock Point N drift Nove Wave direction DOMINAN mber– April–October A SEA M T DRIF a Sea rc Dunes h N T Beach N Beach Cliff Wind and wave direction Movement of wave Rocky shore onto beach Edge of Backwash shoreline during: New sand and Direction beach Autumn rock deposits material is moved Spring QUIET CORNER NXm\jYi`e^`e^dXk\i`XckfXY\XZ_ ?fncfe^j_fi\[i`]kfZZlij J\XjfeXccfe^j_fi\[i`]kXk9cXZbIfZb# GfikG_`cc`g9Xp 6 X @en_`Z_[`i\Zk`fe`jk_\Y\XZ_dXk\i`Xcdfm`e^`e k_\d`[[c\[`X^iXdXYfm\6<ogcX`en_p% REMEMBER Y ?fnd`^_kk_`jY\XZ_Z_Xe^\`]`ke\m\i \og\i`\eZ\[j\XjfeXccfe^j_fi\[i`]k6 1 N_Xk`jX k_\jnXj_Xe[Y k_\YXZbnXj_6<ogcX`e 7 CffbZcfj\cpXkk_\[`X^iXdXYfm\i`^_k% n_Xkpfld`^_k\og\Zkkfj\\n`k_\XZ_% X <ogcX`en_p#[li`e^Xlklde#k_\j\XnXj_\jlg 2 ;\jZi`Y\#`e^\e\iXck\idj#_fn[\jkilZk`m\Xe[ X^X`ejkk_\Zc`]]jXkk_\jflk_\ie\e[f]k_\Y\XZ_% ZfejkilZk`m\nXm\jX]]\Zkk_\j_Xg\Xe[Z_XiXZk\i`jk`Zj Y N_p_Xjk_\j_Xg\f]k_\Y\XZ_Z_Xe^\[X^X`eYp
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    ESHANESS – inside Shetland’s volcano Explore Eshaness! The Eshaness coast is one of the walks on the Geopark Shetland Volcano Trail. We went up to Eshaness lighthouse and then took a walk around the coastline. We explored the Grind o da Navir and we had to find out how it was formed. There are magnificent cliffs and most of the land from the lighthouse to the Grind is easy to walk on. Discover Shetland’s volcano Discover coastal erosion We discovered that parts of Eshaness used to be a volcano. The rock in this At the Grind o Da Navier there is a big piece of land being eroded away by the sea. The sea is so area is igneous rock. powerful that it flings huge rocks as big as small cars over 50 metres inland. The blowhole next to the lighthouse, Kirn o Slettans, was a side cone on the There is a lot of erosion along the Eshaness coast as the sea works its way into cracks in the volcano. On windy days when the sea is rough water can shoot up out of rocks. The Hols o Scraada is a partially collapsed sea cave. the blowhole. The rock around the blowhole is made of volcanic blocks and bombs all stuck together. Erosion can make the coastline loose and crumbly but you should not take rocks from this area as it is part of our geological heritage. The cliffs are made of cooled lava called basalt. This is extrusive Conserving this heritage is an important part of being a Geopark.
  • The Blowhole the Flagstaff Area Has a Number of Holes in the Ground from Which Air from Underground Chambers Blows at Speeds Approaching 30 Mph

    The Blowhole the Flagstaff Area Has a Number of Holes in the Ground from Which Air from Underground Chambers Blows at Speeds Approaching 30 Mph

    Rio Hondo Prep Arizona Geology Field Camp Geology Basics Let’s start off with a review of the major rock Sandstone whose layers are at different angles are classes. called cross-bedded sandstone. They are formed There are three different types of rocks, when winds change direction on sand dune deposits Sedimentary, Igneous and Metamorphic. Any rock which account for the different angles of the layers. that exists can be classified in one of these three categories, which are named dependent on how the rock formed. SEDIMENTARY ROCK Sedimentary rock is formed in a one of two ways, thus there are two types of Sedimentary rock, clastic and non-clastic (organic or chemical composition). Clastic Sedimentary rock is formed from bits and pieces of pre-existing rock that has been weathered (broken apart), eroded (transported away from its original location, usually by water or wind), and deposited. The loose deposits are then buried by other deposits, which compact the tiny grains together. The grains are then ‘cemented’ together to Limestone is found throughout Northern Arizona, form new rock. and is the surface rock type in most of Flagstaff and One of the common rock types in Arizona is the Grand Canyon. Sandstone. Sandstone is a clastic sedimentary rock formed when sand- sized grains (mostly quartz) eroded from other rocks are deposited in a layer which is later compressed by sediments above it. Compression is only part of the process; water from the surface which contains calcium and other elements form a cement to make the rock hard. If this Limestone is commonly formed in a clear, warm, shallow sea.
  • National List of Beaches 2008

    National List of Beaches 2008

    National List of Beaches September 2008 U.S. Environmental Protection Agency Office of Water 1200 Pennsylvania Avenue, NW Washington DC 20460 EPA-823-R-08-004 Contents Introduction ...................................................................................................................................... 1 States Alabama........................................................................................................................................... 3 Alaska .............................................................................................................................................. 5 California.......................................................................................................................................... 6 Connecticut .................................................................................................................................... 15 Delaware........................................................................................................................................ 17 Florida ............................................................................................................................................ 18 Georgia .......................................................................................................................................... 31 Hawaii ............................................................................................................................................ 33 Illinois ............................................................................................................................................