Landscapes and Landforms PDF

Topic 1 Landscapes and landforms Source 1.1 The Painted Cliffs, Maria Island National Park, Maria Island, Tasmania, Australia ISBN 978-1-316-60144-0 © Thompson et al. 2016 Cambridge University Press Photo...

Topic 1 Landscapes and landforms Source 1.1 The Painted Cliffs, Maria Island National Park, Maria Island, Tasmania, Australia ISBN 978-1-316-60144-0 © Thompson et al. 2016 Cambridge University Press Photocopying is restricted under law and this material must not be transferred to another party. ISBN 978-1-316-60144-0 © Thompson et al. 2016 Cambridge University Press Photocopying is restricted under law and this material must not be transferred to another party.  Landscapes and landforms 1 Source 1.2 The Three Sisters, Katoomba, New South Wales, Australia Before you start convergent (subduction) plate boundary deposition Main focus destructive forces The Earth is made up of many different types divergent plate boundaries of landscapes and their distinctive landform erosion features, which are shaped by geomorphic fault lines processes. geomorphic processes landform Why it’s relevant to us landscape Geomorphic processes directly impact people. tectonic activity Sustainable human use of land resources transform plate boundary depends on knowing how landscapes develop weathering and change. Inquiry questions Let’s begin What are the different types of landscapes Geography is an important subject as it is the and landforms? study of places and the relationships between Do different rocks produce different people and their environments. In this chapter landforms? we discuss different types of landscapes, and In what ways do weathering and erosion landforms. A landscape is an area, created by a contribute to landform development? combination of geological, geomorphological, What were the effects of the Tambora biological and cultural layers that have evolved volcano eruption in 1815? over time e.g. riverine, coastal or urban Key terms landscapes. Landforms are the individual surface features of the Earth identified by their collision plate boundary shape e.g. dunes, plateaus, canyons, beaches, constructive forces plains, hills, rivers, valleys. ISBN 978-1-316-60144-0 © Thompson et al. 2016 Cambridge University Press Photocopying is restricted under law and this material must not be transferred to another party.  Chapter 1 Landscapes and landforms   25 1.1 Different landscapes and landforms TOPIC 1: LANDSCAPES AND LANDFORMS Landforms of varying sizes and example, landforms will landform the individual riverine associated with surface features of shapes, when taken together, include a channel, possibly rivers the Earth identified by are referred to as a landscape. a levee, and a flood plain or arid dry or parched, their shape e.g. dunes, Landscapes can be seen and terrace. refers to regions such as plateaus, canyons, deserts beaches, plains, hills, Some landforms, like the studied on topographic maps. rivers, valleys channel the hollowed- There are many different types arid zone dunes found in the out path formed by a landscape a landscape Arabian Peninsula or central river or stream is an area, created of landscapes, including but by a combination Australia, are very large and levee a sediment of geological, geo- not limited to: embankment bordering morphological, biological can extend for hundreds of a channel and cultural layers that coastal landscapes kilometres. Other landforms, flood plain low-lying have evolved overtime riverine landscapes e.g. riverine, coastal or like individual pedestal ground that is subject to urban landscapes arid landscapes flooding from a nearby rocks shaped like an anvil or river topographic map a mountain landscapes detailed, large-scale map mushroom, are generally small terrace a ‘platform’ of karst landscapes. fairly flat land, often a of part of the Earth’s and reach only a metre or so in surface which illustrates former flood plain that Landforms within each height. Geographers and others has become stranded the shape of the land and selected natural and landscape have distinctive by later down-cutting by try to explain these differences human features from the the river surrounding environment features. In downstream in size, shape and grouping of riverine landscapes, for landforms. Source 1.3 An example of a coastal landscape at Rottnest Island, Western Australia ISBN 978-1-316-60144-0 © Thompson et al. 2016 Cambridge University Press Photocopying is restricted under law and this material must not be transferred to another party.  26  Geography NSW Syllabus for the Australian Curriculum Stage 4 7 & 8 Activity 1.1 1 Distinguish between a landform and a landscape. 2 List the types of landforms found in riverine landscapes. 3 Select another type of landscape (for example, a coastal or arid landscape) and list the types of landforms you may find. 1.2 Geomorphic that have evolved over time in response to different forces acting on them. processes The geomorphic processes geomorphic that produce landforms 1.3 Weather and climate processes natural processes that transform are both large and small the lithosphere to create People often use the terms ‘weather’ and distinctive landscapes in scale. The Earth’s entire ‘climate’ interchangeably, believing they mean and landforms e.g. surface, whether exposed as erosion, weathering, the same thing. They certainly are related, but tectonic activity landmasses or lying beneath their meaning is quite different. constructive forces the ocean, is constantly being Weather refers to the those that build new changed by a combination of weather the condition landforms or add to short-term conditions in a of the atmosphere at those already there constructive and destructive certain location. Our weather a point in time e.g. forces acting at different rates; temperature, humidity destructive forces comes from the layer of those that wear down it is affected by weathering, and degrade landforms, the atmosphere closest to infrastructure and erosion, deposition and the earth’s surface, called property tectonic activity. the troposphere, and is largely driven by air weathering the Large-scale plate breakdown of rocks and pressure. Day-to-day weather conditions vary sediments into smaller movements, tectonic uplift and in terms of: particles or a solution volcanic eruptions contribute erosion the wearing temperature to new or higher areas of away of the surface of wind speed and direction precipitation forms the Earth by the action of ground. At the same time, these of water falling from wind and water cloud cover the atmosphere to the surfaces are continuously being deposition the process precipitation (rain, hail, Earth’s surface e.g. rain, worn down by weathering and hail, snow, sleet of eroded material being snow) deposited erosion, and the products of climate the average humidity. types of weather, tectonic activity these processes accumulate movement of layers of including seasonal as sediments in lower parts of Climate, on the other hand, variations, experienced the Earth’s crust known as plates that move and continents and oceans. Both refers to long-term patterns by a place or region over float a long period of time constructive and destructive in a region. Meteorologists forces are operating, but collect weather data over time with different intensities and effectiveness at and can determine trends such as seasonal different times and in different places. When ranges in temperature and average annual we look at landforms, we are seeing features rainfall. For example, Darwin is classified as ISBN 978-1-316-60144-0 © Thompson et al. 2016 Cambridge University Press Photocopying is restricted under law and this material must not be transferred to another party.  Chapter 1 Landscapes and landforms   27 having a tropical climate based upon long- For example, the transportation of already- term data collected (over months and years). detached quartz grains by wind can cause TOPIC 1: LANDSCAPES AND LANDFORMS In comparison, Sydney’s climate is described these grains to then abrade against a rock and as ‘temperate’. This means that the city tends detach additional particles. On a windy day at to experience warm days in summer and cool the beach, sand grains will impact against bare days in winter. legs and do the same to any rocks exposed Weather is more immediate and short nearby. Loose grains on rock surfaces will term, whereas climate refers to the long-term then be removed and transported by the patterns. You could also describe climate as wind. If local topography is being the ‘average’ of all the weather for a sloping and water erosion is quartz rock composed of silicon dioxide; a particular region. active, weathered materials hard mineral that resists will be transported away weathering Weathering and from their original site and abrade to wear down biophysical processes interconnected erosion moved further downslope. by rubbing against something sequences that form and transform natural Weathering and erosion are Sometimes sediments will drainage network environments in a cause- closely linked biophysical be transferred directly into pattern of gullies, and-effect relationship streams, rivers and lakes e.g. erosion, deposition, processes, sometimes being drainage networks, but more in a drainage basin that soil formation, nutrient so connected that it can be usually sediment transport allows water to flow to cycling the lowest point difficult to separate them. on hill slopes is a ‘stop–start’ Source 1.4 A landscape produced through soil erosion around Lake Bogoria, Kenya ISBN 978-1-316-60144-0 © Thompson et al. 2016 Cambridge University Press Photocopying is restricted under law and this material must not be transferred to another party.  28  Geography NSW Syllabus for the Australian Curriculum Stage 4 7 & 8 operation, with temporary the water turbid; this water depressions sunken turbid cloudy or muddy places or hollow storage points in small becomes visible in estuaries estuary a body of water surfaces depressions or flatter areas. and in any rivers entering formed where fresh water Sediment that enters drainage the sea. from rivers and streams flows into the ocean, lines following heavy rainfall will make mixing with the seawater Activity 1.2 1 Identify sites in your local area that have been affected by weathering and erosion. 2 Outline how weathering and erosion alter the Earth’s surface. 3 Research via the internet and then list some iconic landforms and landscapes that have been affected by weathering and erosion. Deposition at the surface or in ocean depths. At the surface, the ocean currents are mainly driven In coastal landscapes by winds. At depths of more than 400 metres Coastal landscapes are formed by weathering, the movement of seawater is controlled by erosion and deposition. Ocean currents and temperature and salinity differences. tides play large roles in these processes. Each of the major oceans has its own For most people, the coast means the system of currents due to continents beach. Beaches can be composed of quartz interrupting oceanic flows. As there are no sands, calcareous sands (broken pieces of continents to obstruct currents flowing around shells), volcanic (black) sands or boulders. The material hydraulic action the process of waves making up beaches comes compressing air within from a combination of rock gaps in the rock, and this air being explosively weathering along the coastline, released when the through hydraulic action waves retreat moving sediments from the longshore drift the movement of sediment, continental shelf to the beach, usually sand, shingle or and rivers depositing their load mud, along a coastline driven by the direction of in the ocean. Sand or other the prevailing wind sediment can be moved along a coastline by ocean currents (longshore drift) and be shifted from one end of a beach to the other. Ocean currents are large-scale, Source 1.5 The Disney character Nemo, a clownfish uninterrupted flows of seawater that follow a like this one here, used the Eastern Australian Current definite path. Currents can be either mainly (EAC) on his journey in the cartoon film Finding Nemo. ISBN 978-1-316-60144-0 © Thompson et al. 2016 Cambridge University Press Photocopying is restricted under law and this material must not be transferred to another party.  Chapter 1 Landscapes and landforms   29 0219 Ocean currents 165º 150º 135º 120º 105º 90º 75º 60º 45º 30º 15º 0º 15º 30º 45º 60º 75º 90º 105º 120º 135º 150º 165º 180º We s t Gre currenenland t nt 75º TOPIC 1: LANDSCAPES AND LANDFORMS ent rr e cu cu rr nl and ree an tic Atl G 60º L a bu r r e th c d or ra nt or N nt e Al as k a c urr eam 45º f str Ca urren Gul nt rre lifo t c N o r t h Pa c i f i c a ) cu rni current hio cu r ori d t os a ry ren nt 30º Cana Fl cur re r J a p a n ( Ku North equa torial No on rth so North dri equ equ a toria l current n ft current Mo a to ria 15º ntre Gui Equ a tor ial co unter Eq l cur ea ua Equa torial counter current n tor cu r rent current ial c E qu a torial coun ounter current ter c 0º Equator torial current th equa ur Sou re u a t or eq nt currrazil ent ia l Pe r curr lhas th 15º B ent u (Hu current Sou Agu South equa toria current l an a li mbo ldt) current current str 30º East Au uela ng Be 45º We s t w i n d d r i f t Antar ctic circumpo lar current We s t wind drift 60º Antarctic circumpolar current 75º Cool current Warm current Source 1.6 World map of ocean currents Antarctica, the west wind drift is the only uninterrupted global current. Tides are caused mainly by the gravitational pull of the moon. A high tide will happen when the moon and sun are tidal range difference in aligned, and the largest tides height between low tide during the year are recorded and high tide when the Earth is closest to the sun. When tidal ranges are very large, there are usually local topographic and seabed features that contribute. Source 1.7 The Hopewell Rocks at the Bay of Fundy, in New Brunswick, Canada. The Bay of Fundy has the largest tidal range (15 metres) in the world. ISBN 978-1-316-60144-0 © Thompson et al. 2016 Cambridge University Press Photocopying is restricted under law and this material must not be transferred to another party.  30 Geography NSW Syllabus for the Australian Curriculum Stage 4 7 & 8 Note this down 1.1 Copy the graphic organiser below and complete the following tasks. 1 Select one place from each of the following two lists. Locate each place on a map. 2 State why tidal ranges are different at these two locations, using descriptions of the locations found on the internet. 3 Explain why is it is important for humans to be aware of tidal ranges. List 1 Location (country Tidal range List 2 Location (country Tidal range (select one) and description) (m) (select one) and description) (m) Broome Newcastle Avonmouth Athens Bay of Fundy New Orleans RESEARCH 1.1 ////////////////// Choose two places on the coast in Australia, one in northern Australia and one in southern Australia. Describe the coastal landforms in each area. Identify any differences in landforms between the two areas. Explain why coastal landforms may not all be the same in northern and southern Australia. In riverine landscapes rivers entering the sea often delta fan-shaped carry massive amounts of clay, deposit of river Both deposition and erosion are processes that silt and sand, and these are sediments found at the occur in rivers. Large-scale deposition usually mouth of a river deposited at the river mouth in happens in the downstream or slow-moving the form of a delta. sections of rivers, while major erosion tends to be concentrated in the upper reaches. meandering a series of wide curves and loops Large rivers can temporarily of a river channel when deposit sediment within their viewed from above channels, usually as a result of meandering or when the river flow slows down and is unable to keep moving all the sediment delivered to the stream. Large ISBN 978-1-316-60144-0 © Thompson et al. 2016 Cambridge University Press Photocopying is restricted under law and this material must not be transferred to another party.  Chapter 1 Landscapes and landforms   31 RESEARCH 1.2 ////////////////// TOPIC 1: LANDSCAPES AND LANDFORMS Research some rivers via the internet and choose one that has slow-moving sections within it resulting in deposition. Describe the river and its location. Differentiate between pools and riffles. Identify reasons as to why deposition has occurred. Explain how a billabong (oxbow lake) forms. List some of the materials contained within the deposition. Note this down 1.2 Copy and complete the graphic organiser below by answering the following questions. 1 Select two large rivers, one in Australia and one in another country. 2 Using information in your table, make two lists of depositional landforms: a those associated with both rivers b those present on only one of the rivers. 3 Make two lists of erosional landforms: a those associated with both rivers b those present on only one of the rivers. 4 Discuss the similarities and differences in depositional and erosional landforms associated with the two rivers selected. River in Australia (name) River in another country (name) Rainfall distribution across the catchment (Heavier in some parts than others? The same everywhere? Approximate amounts?) Depositional landforms present 1 2 3 Erosional landforms present 1 2 3 ISBN 978-1-316-60144-0 © Thompson et al. 2016 Cambridge University Press Photocopying is restricted under law and this material must not be transferred to another party.  32  Geography NSW Syllabus for the Australian Curriculum Stage 4 7 & 8 In arid landscapes About 70% of Australia is classified as arid or and deposited by aeolian (wind) processes, semi-arid due to our low rainfall. In Australian often forming interesting patterns such as deserts, such as the Simpson Desert, there are longitudinal dunes, crescent-shaped dunes, many dunes. Sand particles are transported star-shaped dunes and transverse dunes. Source 1.8 The Simpson Desert and its dunes ISBN 978-1-316-60144-0 © Thompson et al. 2016 Cambridge University Press Photocopying is restricted under law and this material must not be transferred to another party.  Chapter 1 Landscapes and landforms   33 TOPIC 1: LANDSCAPES AND LANDFORMS Ta n a m i D e s e r t Source 1.9 There are 10 major deserts in Australia including the Great Victoria Desert, the Simpson Desert, the Sandy and Tanami Deserts. A large proportion of this land belongs to the Aboriginal and Torres Strait Islander peoples. Activity 1.3 1 Discuss how rivers are agents of both erosion and deposition. Refer to distinct features you might expect to see as evidence of these processes. 2 Identify why deserts are generally found at a latitude of 30° north or south latitude distance from of the Equator. Use the ocean currents map (page 29) to explain why the Equator measured in degrees north or south deserts are mostly located on the western side of continents or inland. 3 Reflect on whether deserts are always hot and dry (with the exception of the Gobi Desert and Antarctica). ISBN 978-1-316-60144-0 © Thompson et al. 2016 Cambridge University Press Photocopying is restricted under law and this material must not be transferred to another party.  34  Geography NSW Syllabus for the Australian Curriculum Stage 4 7 & 8 Geographical fact People often assume deserts are always hot and dry. Although this is mostly the case, it is also not accurate. Deserts do receive rain each year, but generally well below average. A desert is classified as a region receiving less than approximately 250 mm rainfall per year. And deserts can get cool. Light overnight frosts in winter are not unusual. In Australia, July minimum temperatures are mostly in the 3–6°C range in our arid regions. The lowest temperatures in an Australian arid area have been recorded at Alice Springs, where the temperature has fallen as low as –7.5°C. Source 1.10 The town of Alice Springs is classified as semi-arid, but has experienced temperatures as low as –7.5°C. In karst landscapes In limestone terrain, bedding plane surface bedding and joint planes between layers of Karst generally refers to the system of caves allow surface water to enter deposited materials or and fissures underground and their unique sandstone that make up environments. More specifically, it refers to and take calcite into the sedimentary rocks a situation when water infiltrates into the solution, thereby widening joint planes vertical, horizontal and angled Earth’s surface in sufficient quantities, and any existing weaknesses or patterns of cracks in moves down to a zone of saturation, the fractures. Over time, this may rocks upper limit of which is termed the water lead to the development of calcite the main mineral in limestone and marble, table. Groundwater moves more slowly than underground streams, which composed of calcium overland flow, as groundwater can only emerge either as springs or carbonate circulate through small, interconnected pore as fully fledged rivers fed by spaces within rock or sediment, but it can still underground water. Freshwater contribute to the formation of landforms. springs appear in the ocean off the coast of ISBN 978-1-316-60144-0 © Thompson et al. 2016 Cambridge University Press Photocopying is restricted under law and this material must not be transferred to another party.  Chapter 1 Landscapes and landforms   35 TOPIC 1: LANDSCAPES AND LANDFORMS Source 1.11 A karst landscape. These landscapes are characterised by eroded rock formations that result in caves and sinkholes. Montenegro in the Adriatic Sea, and offshore karst or flat-bottomed valleys tower karst towers from Yucatán in the Gulf of Mexico. and tropical-region tower or pinnacles remaining Limestone regions and those with soluble karst, also occur. When dense, after limestone has been weathered in tropical rocks like gypsum have often developed compacted limestone is uplifted, regions distinctive karst topography due to the action gorges can be cut through the characteristics the of underground water. On the rock. Because surface water tangible and intangible elements of a place or karren small grooves or surface, small-scale features tends to disappear quickly environment furrows in rock (usually like karren are common. At into limestone terrain through limestone) formed by running water a slightly larger scale, various bedding planes and joints, other features appear: sinkholes, and then enlarge them, another characteristic disappearing streams and springs. More of limestone regions is the development of extensive landforms, like limestone pavements, extensive cave systems. ISBN 978-1-316-60144-0 © Thompson et al. 2016 Cambridge University Press Photocopying is restricted under law and this material must not be transferred to another party.  36 Geography NSW Syllabus for the Australian Curriculum Stage 4 7 & 8 Source 1.12 The Nullarbor Plain is the world’s largest limestone karst landscape. Caves are a common feature. Tectonic activity Activity 1.4 Plate tectonics movements tend to influence the formation of mountains over millions of 1 Suggest what conditions lead to years. Tectonic plate movements occur both on the formation of a desert. continents and on ocean floors. 2 Describe how mountains are Tectonic activity and volcanoes formed. By investigating patterns of divergent plate 3 List two landforms developed in boundaries the point volcanic activity and the absolute where plates are pulled limestone by groundwater, and two amount of continental movement apart, allowing molten developed in non-limestone areas. rock to emerge at the over a number of years, Earth’s surface 4 Explain why groundwater is so scientists have proposed that collision plate important to landform development plates are moving in different boundary the point in limestone terrain. where two plates of pathways and at different rates. similar strength or speed Some plate boundary locations collide and movements are unclear, convergent (subduction) plate and these are referred to as boundary the point plate boundary zones. Different where two plates are moving towards each landforms are associated other and collide, with with different kinds of plate one plate being pushed beneath the other; boundary, giving clues to the the lower plate is the way plates are behaving. The ‘subducted’ plate main plate boundary types are transform plate boundary the point described as divergent, collision, where two plates slide, convergent (subduction) or grate or jerk past one another transform. ISBN 978-1-316-60144-0 © Thompson et al. 2016 Cambridge University Press Photocopying is restricted under law and this material must not be transferred to another party.  Chapter 1 Landscapes and landforms 37 1 Divergent (continental plates) 2 Divergent (oceanic plates) (e.g. Rift Valley, Africa) (e.g. Mid-Atlantic Ridge) TOPIC 1: LANDSCAPES AND LANDFORMS volcano major volcanic activity crust oceanic plate magma rises through asthenosphere magma rises through asthenosphere weakened crust weakened crust 3 Collision (continental plates) 4 Subduction (continent/ocean) (e.g. Andes, South America) (e.g. Ring of Fire, Pacific Ocean) fold mountains trench continental crust thickening of crust crust oceanic plate from collision asthenosphere asthenosphere 5 Transform boundary (plates moving past each other) (e.g. San Andreas fracture zone) (a) viewed from above (b) cross section rocks often do not match on either side of the boundary/fracture boundary boundary Source 1.13 Divergent/collision/subducting/transform plate boundaries Volcanic activity occurs along collision, As many convergent plate boundaries are convergent and divergent plate boundaries, on or near landmasses, explosive volcanism is both under the oceans and what people generally experience. The ‘Ring fault lines lines on the on landmasses, and along of Fire’ around the Pacific Ocean represents earth’s surface that trace fault lines. Transform plate more than 1000 volcanoes that have appeared a break boundaries, where plates move on convergent plate boundaries. Of those past each other, generally are volcanoes that have erupted during historical not associated with volcanic activity. Much time, the highest is in the Andes in northern of the volcanism found along convergent Chile, at an elevation of nearly 7000 metres. plate boundaries is explosive, while most There is evidence of submarine volcanism volcanic activity taking place along divergent having taken place over the last 150 years boundaries involves non-explosive outpourings at depths of about 5300 metres in the Mid- of lava. Atlantic Ridge (divergent plate boundary). ISBN 978-1-316-60144-0 © Thompson et al. 2016 Cambridge University Press Photocopying is restricted under law and this material must not be transferred to another party.  38  Geography NSW Syllabus for the Australian Curriculum Stage 4 7 & 8 Source 1.14 Indonesia still has active volcanoes such as Ijen in Java. Ijen has the world’s largest acidic crater lake, famous for its striking azure colour. Some workers make a living from carrying sulfur out of the crater. Note this down 1.3 Copy the graphic organiser below and give an example of each boundary type and associated landforms. Nature of plate boundary Example (location) Landform/s Collision Himalayas High mountains Divergent Convergent (subduction) Transform Activity 1.5 1 Using the internet, locate two maps showing: a the Pacific ‘Ring of Fire’ b plate movements. 2 Identify the link between the types of plate boundaries around the Ring of Fire (collision, convergent (subduction), divergent or transform). 3 Consider whether particular types of plate boundaries have caused the Ring of Fire. 4 Investigate the career of a vulcanologist. How do you become a vulcanologist? What do vulcanologists do? And are there any famous vulcanologists? Choose one and give a short summary of their career and major findings. ISBN 978-1-316-60144-0 © Thompson et al. 2016 Cambridge University Press Photocopying is restricted under law and this material must not be transferred to another party.  Chapter 1 Landscapes and landforms   39 RESEARCH 1.3 ////////////////// TOPIC 1: LANDSCAPES AND LANDFORMS In groups, select one of the major continental or oceanic plates and use the internet to gather information about the rate and direction of its movement. Assess what the likely outcomes of this movement will be over the next century, and share your results with the class in the form of a PowerPoint presentation. 1.4 Examining a landscape and its landforms Mountain landscapes Generally mountains are If the plates have collision plate anticline the upward boundary the point formed due to collision plate approximately the same rock bulging of rocks caused where two plates of boundaries. These boundaries density, the collision forces by compression similar strength or occur when plates are moving parts of the landmasses syncline the downward speed collide squeezing of rocks towards one another, resulting upwards. The top of a fold caused by compression in the plates colliding. Even though plates is known as an anticline, are moving slowly, they often adjust quickly, whereas the bottom of the causing earthquakes. fold is the syncline, which represents the 0108 Tectonic plates Divergent boundaries Transform faults Collision boundaries Subduction boundaries E u r a s ia n No r t h p la t e Am e r ic a n pla t e Arabi an pl ate Phi l i ppi nes A f ri can Caribbean pl ate Cocos pl ate plate plate Pa c ific pla t e Na z c a So ut h I n d ia n – A u s t r a lia n pla t e p la t e Am e r ic a n pla t e Ant a rc t ic pla t e 0 3000 6000 km Source 1.15 Tectonic plates and their boundary conditions ISBN 978-1-316-60144-0 © Thompson et al. 2016 Cambridge University Press Photocopying is restricted under law and this material must not be transferred to another party.  40 Geography NSW Syllabus for the Australian Curriculum Stage 4 7 & 8 nearby rocks that have been folded over themselves or monocline a simple fold recumbent folds those that occurs singularly squeezed downwards into a overturned (‘reclining’), so that that have folded over rather than as part of a convex shape. Monoclines are initially the youngest rocks themselves or appear series of anticlines and to have flopped over, synclines a more simple and gentle fold are on the surface. Recumbent strongly folded and – for example, the Lapstone folds are frequently sighted in squeezed into sharp folds as a result of great Monocline at the eastern part strongly folded terrains like the horizontal pressure of the Blue Mountains Range in New South European Alps. Wales. Recumbent folds are those that have Anticline Recumbent fold Monocline Syncline Imaginary land surface Source 1.16 Different fold types Source 1.17 Matterhorn in the Swiss Alps, part of the European Alps, which has many examples of recumbent folds ISBN 978-1-316-60144-0 © Thompson et al. 2016 Cambridge University Press Photocopying is restricted under law and this material must not be transferred to another party.  Chapter 1 Landscapes and landforms   41 Geographical fact Geographical fact TOPIC 1: LANDSCAPES AND LANDFORMS The Himalayas mountain range grows by The Nullarbor Plain is the world’s largest approximately 1 cm a year. Therefore limestone karst landscape, covering 270 000 Mt Everest will be another metre higher in square kilometres. Nullarbor means ‘no trees’. 100 years. Two-thirds of the Nullarbor is in WA and one- third in SA. Source 1.18 A famous example of an anticline is the Himalayas, where the Indo-Australian Plate is moving northwards and the Eurasian Source 1.19 The karst landscape of the Plate is moving southwards. Nullarbor plain Volcanoes tonnes of sulfur – more than six times the amount from Mt Pinatubo (Philippines) in In 1815, the largest volcanic eruption during historical times took place in the Flores Sea 1991 – and large amounts of fluorine, which is near Lombok in Indonesia. Tambora had toxic to people and livestock. The violence of been considered an extinct volcano until then, the eruption sent plumes of ash up to 43 km when approximately 50 km3 into the atmosphere, and explosions could be caldera large basin- of dense rocks were ejected. heard up to 2000 km away. shaped depression During the worst few days of the eruption, caused when the summit Before the eruption, Tambora of a volcano collapses stood at about 4300 metres many places within 600 km of the volcano into the magma chamber but the summit exploded, remained ‘pitch black’, and air temperatures below or explosions destroy the summit leaving a caldera measuring 6 dropped dramatically. Global temperatures may pumice a light-coloured km wide and 1 km deep. The have dropped by up to 3°C. The after-effects of rock with many holes (vesicles) due to gases new summit reached only 2850 the volcanic eruption were severe. Immediately mixing with rapidly metres, a collapse of nearly following the eruption and associated solidifying lava and trapping multiple air 1.5 km. Apart from massive earthquakes, tsunamis reached a maximum bubbles. Pumice is light pumice flows, the volcano height of 4 metres and inundated low-lying and floats on water. ejected an estimated 60 million coastal areas. Ash build-up caused buildings to ISBN 978-1-316-60144-0 © Thompson et al. 2016 Cambridge University Press Photocopying is restricted under law and this material must not be transferred to another party.  42  Geography NSW Syllabus for the Australian Curriculum Stage 4 7 & 8 collapse and people had difficulty breathing. Hemisphere. On the positive side, sunsets and At least 71 000 people are estimated to have twilights in places like London were spectacular. died during the eruption or immediately However, the year following the eruption – afterwards, when no food or uncontaminated 1816 – was called the ‘year without a summer’ water was available. in northeast North America and Europe. That Up to 3 years after the eruption, pumice and year, the weather was much wetter than usual tree trunks formed sea-borne rafts up to 5 km and cold temperatures shortened the growing across, and posed a major hazard for shipping. season. Grain crops failed, potatoes rotted in The massive quantities of ash ejected into the the wet ground and people suffered from major atmosphere had climate impacts in the Northern outbreaks of typhus. Source 1.20 This detailed astronaut photograph depicts the summit caldera of the volcano. The huge caldera – 6 kilometres in diameter and 1100 metres deep – formed when Tambora’s estimated 4000-metre high peak was removed, and the magma chamber below emptied during the 1815 eruption. Activity 1.6 Geographical fact 1 Locate the Tambora volcano on a map. Pumice stones were used by clothing 2 Identify whether the Tambora volcano manufacturers to produce the original stone- lies on or near a plate boundary. washed jeans. 3 Assess two impacts of the Tambora eruption on human populations. ISBN 978-1-316-60144-0 © Thompson et al. 2016 Cambridge University Press Photocopying is restricted under law and this material must not be transferred to another party.  Chapter 1 Landscapes and landforms   43 Chapter summary TOPIC 1: LANDSCAPES AND LANDFORMS There are many different types of Rivers are agents of both deposition and landscapes, including coastal, riverine, arid, erosion e.g. deltas. mountain and karst. Arid regions tend to be deserts, often found ‘Weather’ and ‘climate’ do not have the around a latitude of 30° north/south of the same meaning. Weather refers to daily Equator. conditions in a particular location. Climate Karst landscapes are limestone regions refers to long-term patterns in a particular where underground water causes distinctive region. landforms such as karst towers or caves. Landforms are created by weathering, Convergent, divergent, subduction and erosion, transportation and deposition. transform plate boundaries lead to different Coastal landforms are formed by types of landforms. weathering, erosion and deposition, particularly by water like the ocean e.g. tides and ocean currents. End-of-chapter questions Short answer Extended response 1 List the two forces which act at different To what extent are landforms developed as rates that contribute to the geomorphic a result of plate movements? Discuss this processes that produce landforms. question in a short report by giving examples 2 Describe a karst landscape. of both large-scale and small-scale landforms, showing your understanding of the role of plate 3 A year after the eruption of the Tambora movements in landform development. What volcano in 1815 what was the term for other factors may affect landform formation? the year in northeast North America and Europe? ISBN 978-1-316-60144-0 © Thompson et al. 2016 Cambridge University Press Photocopying is restricted under law and this material must not be transferred to another party.