Unit 5: Surface Prcesses What are the prcesses that shape ur Earth? Name: 1
Tpics: Weathering: Physical vs. Chemical Sil Frmatin Agents f Ersin Stream Velcity and Transprted Particle Size Changes caused by ersin Factr affecting Depsitin Srting f Sediments Depsitinal Features Ersinal-Depsitin Systems: Running Water Glaciers Mass Mvement, Wind and Waves Landscapes Drainage Patterns 2
Why d Rcks Weather? Outcrp - Weathering - Sediments - Weathering ccurs when rcks are expsed t: Mst weathering ccurs when rck is expsed t the atmsphere r grundwater. As slid rck is brken apart, weathering usually increases. There are tw types f weathering: and Physical Weathering Physical Weathering - Types f Physical Weathering: 1) Frst Actin - Water cracks in the rcks and when it freezes it causing the rcks t split apart. 2) Plant/Rt Actin - 3) Abrasin The wearing dwn f rcks as they r against each ther. 4) Exfliatin The away f large sheets f materials at the surface f a rck due t changes in and. 3
Chemical Weathering Chemical Weathering - The rate f chemical weathering in, climates. Types f Chemical Weathering: 1) Oxidatin The break dwn f rck when cmbines with t make, taking n a clr. 2) Hydratin/Hydrlysis The breakdwn f rck when cmbines with minerals in rcks. When rcks sit in water fr extended perids f time, they begin t breakdwn and have a texture. 3) Carbnatin Water cmbines with t frm. Carbnic acid can mst rck, especially. (Remember it bubbles with acid!?!!?) Acid Rain Acid rain frms when cmbines with minerals. Acid rain will fall nt the surface f earth, seep int the grund and limestne bedrck. This prcess creates. If a cavern cllapses, it can create a sinkhle. Sinkhle - 4
Weathering Rate Factrs that Effect Weathering Rate f Weathering - Weathering rate depends n 3 factrs: 1) Surface Area as surface area, weathering rate. Surface Area A full, slid blck has the least surface area expsed. The interir is safe frm expsure t agents f weathering. Increasing Surface Area A cracked piece f rck has the greatest surface area expsed. The interir can nw be weathered. 2) Mineral Cmpsitin Cmparing rck resistance t Weathering In the table belw, cmpare mineral prperties and the effect they have n weathering rate f rcks. Rck Mineral Cmpsitin Hardness Resistance t Weathering Granite Limestne The diagram t the right shws a gelgic crss sectin. Which letter is mst resistant t weathering? Which letter is least resistant t weathering? A B C D E F 5
3) Climate different climate cnditins prmte varius kinds f weathering. Climates Cnditins fr Physical Weathering Climate Cnditins fr Chemical Weathering 1. Which climate cnditins wuld prduce very slight weathering? a) a mean annual temperature f 25 C and a mean annual precipitatin f 100 mm b) a mean annual temperature f 15 C and a mean annual precipitatin f 25 mm c) a mean annual temperature f 5 C and a mean annual precipitatin f 50 mm d) a mean annual temperature f -5 C and a mean annual precipitatin f 50 mm 2. Why is n frst actin shwn fr lcatins with a mean annual temperature greater than 13 C? a) Very little freezing takes place at these lcatins. b) Large amunts f evapratin take place at these lcatins. c) Very little precipitatin falls at these lcatins. d) Large amunts f precipitatin fall at these lcatins. 3. There is n particular type f weathering r frst actin given fr the temperature and precipitatin values at the lcatin represented by the letter X. Why is this the case? a) Only chemical weathering wuld ccur under these cnditins. b) Only frst actin wuld ccur under these cnditins. c) These cnditins create bth strng frst actin and strng chemical weathering. d) These cnditins prbably d nt ccur n Earth. 4. What type f weathering dminates when the mean annual temperature f -5 C and a mean annual precipitatin f 60 mm? 6
Hw des Sil (Reglith) frm? Sil - and weathering prcesses are imprtant in the f sil. Transprted Sil Sil Classificatin Residual Sil Sil Hrizns layers in sil with distinct characteristics. Hrizn Characteristics O A B C Humus - Sil Cmpsitin: 7
Ersin After rcks are brken up frm weathering, they need t be mved. Ersin - Over time ersin helps and all surface features. Frce f Ersin The driving frce f ersin is Agents f Ersin that are set in mtin by gravity that causes t Examples f Agents f Ersin: Ersin by Water Running Water - causes water t flw In wet climates, running water is the agent f ersin. Water transprts sediments in several ways. - particles are s small they cannt be filtered ut f water. - particles are t small t settle n their wn. - particles are t large t flat in the water, they are alng the bttm f the riverbed. Directin f water mvement 8
Velcity Velcity Velcity f Streams - The faster the stream mves, the mre sediment it can carry. Stream velcity depends n tw factrs. - the amunt f water flwing in the stream. - the slpe f the stream. Discharge Gradient The velcity f the stream determines the f the particles the can carry. Particle Sand Range f Particle Diameter Minimum Velcity Pebbles Cbbles 1) What is the largest rck particle that can be transprted by a stream with a velcity f 250 centimeters per secnd? 2) What is the apprximate minimum stream velcity needed t keep a particle with a diameter f 25.6 centimeters mving? 3) Which is the largest sediment that culd be carried by a stream flwing at a velcity f 75 centimeters per secnd? 4) If a river with an initial velcity f 250 cm/sec slws t a velcity f 100 cm/sec, what size particles wuld be depsited (drpped) by the stream? 9
Depsitin Depsitin - Sediments are depsited in lcatins where they frm f rck. Depsitinal Srting Srting is the prcess f sediments accrding t their characteristics: - larger sediments will settle faster - runder sediments settle faster and flatter sediments will take lnger - mre dense sediments will settle faster Particles sizes are: Example: depsitin frm a Particle sizes are: Example: depsitin frm a Hrizntal Srting when the f a wind r water ersinal systems gradually ; the,, and gradually decrease as yu mve farther ut. Large Small Vertical Srting r mre sediments settle t the bttm first, fllwing by decreasing size and density. Distance frm surce Velcity Particle Size Small n Large n 10
Settling Rate Settling Rate Settling Rate Factrs affecting depsitin rate: 1) 2) 3) Particle Size Settling Rate Particle Size Particle Density Settling Rate Particle Density Particle Shape Settling Rate Rund Oval Flat 11
Ersinal Depsitinal Systems Ersinal - Depsitinal System - On a wrldly scale, the amunt f ersin will be in balance with the amunt f depsitin. This is knwn at. Running Water Running water is the mst cmmn agent f ersin. Stream - Tributary - Fld Plain - Levee - Delta - Streams carry sediment in varius ways: 1) Disslved minerals in 2) particles are suspended in water 3) Larger are usually carried by,, r sliding alng the stream bttm As sediments mve dwn a stream, they becme, and. 12
Stream Velcity - the speed f the stream Which stream will erde mre sediments? Gradient - slpe f the stream Discharge - amunt f water that flws past a given pint given time Channel Shape - WHY? at a Variatins in stream velcity: When a stream channel is the greatest velcity is in the When the stream channel the greatest velcity is n the f the curve. Label where the river is FAST and SLOW: Label where the river experiences EROSION and DEPOSITION 1. 1. 2. 2. 3. 13
Stream Characteristics V-Shaped Valley - f a stream. Meanders as a stream grws lder it begins t shift its curse in a series f r called meanders. The stream seeks ut the path f least resistance. - Pint Bars slw mving water where takes place - Cut banks fast mving water where takes place. 1. Label the diagram (n the right >>) where the river is experiencing EROSION and DEPOSITION. 2. Sketch the prfile view f the river at each labeled crss sectin. 14
Life Histry f a Stream Age f Stream Yuthful Stream Stream Characteristics - - shaped valley - energy - mving water - gradient (slpe) - f ersin Mature Stream Old Age - gradient (slpe) - mving water - Side walls f the V shaped valleys - develp (curves in the river channel) - becmes wider than the river channel - develps (where excess water ges when the river verflws) - Land is almst - frm (a place arund a stream where sediments depsit) - - a cut ff meander 15
Glaciers Glacier - Where d we find glaciers? temperatures latitudes (Nrth and Suth Ples) elevatins (muntaintps) Regins where mre falls in the winter than in the summer. Glacier Mvement: As snw and ice the glacier mves under its wn mass and the pull f. Smetimes glaciers are called a because glaciers act like fluids and flw in a plastic-like mtin. Glaciers flw anywhere frm a few millimeters up t meters per day. Types f Glaciers: (Ice Sheets) huge sheets f ice that cver entire land masses. (Alpine) glaciers that frm in high elevatins in muntain valleys. Valley-Glacier Features U-Shaped Valley - shape f the valley walls frm glacial ersin Transprts any size sediments, including sediments are Striatins (Glacial Grves) lng parallel caused by the grinding as the glacier mves ver bedrck. 16
Cntinental-Glacier Features - large depsited fragments that can be transprted hundreds f miles inside r n tp f the glacier Example: Large bulders f metamrphic rck frm the Adirndack Muntains can be fund many miles suth f this regin. streamlined val shaped munds f unsrted sediment - a lng winding ridge f sands and gravels a mund f till depsited alng the leading edge f a glacier unsrted sediments depsited by a glacier lng parallel scratches frmed by sediment embedded in a glacier that has passed ver the surface The grves indicate the directin the glacier has traveled - depressin left in the grund that is filled with glacial melt water Example: Lake Rnknkma - brad glacial feature f smaller sediment carried frm the melting water f a retreating glacier Example: Suth shre f Lng Island 17
Lng Island s Glacial Histry Lng Island was frmed by glaciers. The Wiscnsinan glaciatin, which happened 85,000 t 11,000 years ag. Large traveled acrss Canada and Nrth America, carrying and. Tw different depsited sediments that led t the frmatin f Lng Island. Abut 55,000 years ag, a glacier advanced just suth f CT, and retreated, frming the Rnknkma Mraine. Abut 20,000 years ag, a glacier advanced just suth f CT, and retreated frming the Harbr Hill Mraine. Glacial Features n Lng Island: - ridges f sediments depsited by retreating glaciers. - like Lake Rnknkma, were frmed by ice falling (and melting) frm receding glaciers. - sandy sediments frm melting water frm receding glaciers. Beaches Nrth Shre Beaches: Beaches n the Nrth Shre tend t be, as sediments were depsited last by the receding glaciers. Suth Shre Beaches: Beaches n the Suth shre are, resulting frm glacial leaving sediments as they recede. 18
Waves and Wind Wind - air that is mving Wind picks up lse sediments such as and and carries them t a new lcatin Deflatin - Abrasin - Sand Dune - Windward Side: slpe Leeward Side: slpe 19
Waves - As pushes a wave tward the shre, it drags alng the bttm f the cean flr The dragging slws the bttm f the wave, but the tp cntinues at the same speed Eventually the wave becmes unstable and Gelgic Features created by Waves: Wave actin sediments because f Beaches beaches are frmed frm and f cntinental ( ) and ceanic ( ) rcks Sandbars - A ridge f sand, frmed alng a shre by the actin f waves and currents prtect barrier islands frm ersin Barrier island - A lng narrw island, running parallel t the main land, made f sand built up by the actins f, and that distribute the sand Prtect the cast frm Waves apprach the shre at an angle, but retreat parallel t the shre, creating a pattern. The zigzag pattern carries sand t the shre. Lng Shre Current - Jetties and grins - Man-made structures built t prtect the cast frm 20
Mass Mvement Mass Mvement Characteristics: Sediment Examples: Mass mvement invlves tw frces: Gravity - the f where bjects fall twards the f the Earth Frictin - When rain weakens the frce f frictin gravity then pulls rck and sediment dwn a slpe. 21
Landscapes Landscape A landscape is regin n Earth s surface that can be identified by cmmn characteristics such as: Types f Landscape Regins: Landscape Type Als called Descriptin f Regin Muntain Plateau Plain A = B = C = 22
Muntains vs. Plateaus A. B. C. Landscape Diagram Elevatin Slpe Bedrck Muntain Plateau What shapes the landscape? Factr Effect n Landscape Shape Uplifting Frces 1. Tectnic Actin Leveling Frces 2. Bedrck Cmpsitin Hardness 3. Human Activity 4. Time/Age Arid 5. Climate Humid 23
Influence f Climate n Landscape 1) Arid Climate Arid = sils with little humus weathering is the dminant frm f weathering annual rainfall plant cver t hld sediment in place and can carry sediments away rapidly This rapid remval f sediments causes arid regins t be characterized by slpes and, landscape features. 2) Humid Climate Humid = sils weathering is the dminant frm f weathering annual rainfall plant life Plant cver prtects the sil frm rapid and. This prduces the slpes characteristic f humid climates. 24
Drainage Patterns Stream Drainage Patterns The directin, drainage pattern and gradient f streams are ften directly related t the resistance and structure f the underlying bedrck. Dendritic Cmmn stream pattern Tributaries flw in the same Fund n undisturbed, rck layers Trellis/Rectangular ccurs where drainage flws alng flds, fault and tilts lks like parallel lines with tributaries Radial Occurs when the streams flw away frm a Lks like spkes n a wheel Develps ver a smth r cne Parallel Annular ccurs n a dme muntain appears t be a pattern with small tributaries ging int each circle 25
NYS Landscape Regins New Yrk State cntains many different landscape regins characterized by different elevatins and varius rck types. High Elevatins: Medium Elevatins: Lw Elevatins: Atlantic Castal Plain - landscape regin frmed during the Cretaceus and Pleistcene Cmpsitin: Elevatin: Manhattan Prng - landscape regin frmed during the Cambrian and Ordvician Cmpsitin: Elevatin: Hudsn Highlands / Tacnic Muntains - landscape regin frmed during the middle f the Prterzic Cmpsitin: Elevatin: Hudsn / Mhawk Lwlands - landscape regin frmed during the Ordvician Cmpsitin: Elevatin: Adirndack Muntains - landscape regin frmed during the middle f the Prterzic Cambrian Cmpsitin: Elevatin: Tug Hill Plateau - landscape regin frmed during the Ordvician Cmpsitin: Elevatin: Erie-Ontari Lwlands - landscape regin frmed during the Silurian Cmpsitin: Elevatin: St. Lawrence Lwlands - landscape regin frmed during the Ordvician and Cambrain Cmpsitin: Elevatin: Allegheny Plateau / Catskills - landscape regin frmed during the Devnian Cmpsitin: Elevatin: 26