How rocks respond to those stresses within the Earth's crust
Explain how rocks respond to those stresses within the Earth's crust by brittle, elastic, or plastic deformation, or by fracturing
Summarize how rocks become folded
Describe the conditions under which rocks fracture
Briefly describe the different types of faults, including normal, reverse, thrust, and strike-slip
Briefly describe the difference between strike and dip
Briefly describe the hydrological cycle
Describe a drainage basin and explain the origins of different types of drainage patterns
Explain how streams become graded
Describe the formation of stream terraces
Describe the processes by which sediments are moved by streams and the flow velocities that are necessary to erode them from the stream bed and keep them suspended in the water
Explain how natural stream levees form
Describe the types of environments where one would expect to find straight-channel, braided, and meandering streams
Explain some of the steps that we can take to limit the damage from flooding
Explain the concepts of porosity and permeability and the importance of these to groundwater storage and movement
Define aquifers, aquitards, confining layers, and the differences between confined and unconfined aquifers
Explain the concepts of hydraulic head, the water table, potentiometric surface, and hydraulic gradient
Describe the flow of groundwater from recharge areas to discharge areas
Describe how observation wells are used to monitor groundwater levels and the importance of protecting groundwater resources
Describe some of the ways that groundwater can become contaminated, and how contamination can be minimized
Sample Solution
Rocks respond to external stresses by either deformative or fracturing processes. Deformations can be brittle, elastic, or plastic in nature depending on the type of rock and the amount of stress applied. Brittle deformation is when rocks break into pieces without any significant change in shape due to forces exceeding the rock’s strength. Elastic deformation is
when rocks deform but return to their original position when the force causing them to deform is removed. Plastic deformation occurs when rocks permanently deform under extended forces which are less than those that cause brittle failure. Rocks may also fracture if stresses exceed their tensile strength; fractures are created by shear and tension forces that push and pull on different sections of a rock body resulting in faulting.
Folding occurs when two sides of a plane move together creating an anticline (upfold) or syncline (downfold). Folds form from regional shortening caused by compressional tectonic stresses forcing sedimentary layers up, over, and around each other creating complex folds structures such as recumbent folds where one limb has been overturned above horizontal and plunging anticlines where both limbs dip at high angles. The degree and type of folding depend on the particular circumstances within which it formed including lithology, rate and direction of compression, temperature, presence/absence of pore fluids etc..
Different types of faults occur according to different patterns associated with tectonic movements along fault lines through Earth's crust including normal faults with dip-slip movement separating blocks as they move away from each other; reverse faults with dip-slip movement pushing blocks together; thrust faults with strike-slip displacement moving part of a block over another along low angle surfaces; and strike-slip faults where displacement occurs parallel to the fault line between two struck blocks moving sideways past one another. Strike refers to the orientation or trend of a line drawn across an inclined bed while dip is its inclination relative to ground level measured 90 degrees perpendicular from strike direction indicate how inclined beds are burying beneath ground surface during folding events.
The hydrological cycle involves solar energy evaporating water from oceans, lakes and land surfaces forming clouds that travel around Earth before precipitating back onto land as rain or snow leading into runoff which moves down slopes towards rivers eventually returning back into ocean basins completing cycle again. Drainage basin encompasses all areas that contribute water flow into streams within it while drainage pattern depends on geologic structure controlling slope gradient determining formation shapes like dendritic branching patterns resembling tree branches developing in homogeneous terrain , trellis netlike pattern forming between intersected joints cutting across different directions found in jointed crystalline terrain etc . Streams become graded after prolonged erosion begins deepening channels maintaining same elevation levels (or grade) relative to base level adjusting velocity based upon increased load carrying capacity due sediment deposition hence slowing flow down clearing way for larger particles settling out leading towards upstream aggradation event shifting streams course further downstream thereby causing increased erosion downstream until next equilibrium point reached achieving stable channel morphology known as graded stream profile . Stream terraces develop through erosional process scouring deeper parts river valleys carving out successive shelf like steps called terraces progressively getting lower closer mountain feet representing former positions levels valley suggesting long term stability during vertical incision event usually occurring slowly over period time allowing flora fauna adapt new conditions provided . Sediments moved through streaming involve processes erosion entrainment transport suspension saltation traction bypassing gradually deposited further downstream until reaches destination point meanwhile velocities necessary keep suspended state higher than threshold velocity needed erode material flowing thus varying amounts large small depending channel size steepness turbulence involved as well capitalizing hydraulic jumps waterfalls cascades enabling complete efficient transportation system existing planet supplying nutrients replenishing energy used various locales ecosystem dynamic balance maintained among physical chemical life processes elements concern hydrosphere encompassing interconnected systems interacting ecosystems providing global sustainability ensuring biodiversity species habitats kept alive order maintain healthy environment overall quality human life preserved . Levees naturally form within streambeds discharging material clogged banks overflowing side setting stage for linear ridge development involving accumulation sand silt mud along edges holding waters place limiting flood risks posed area offering protection inhabitants living vicinity assisting agricultural needs manage crops grown connected still unchanged restoring natural environment functioning properly . Geomorphologists distinguish variety types environments straight channels braided meandering most commonly seen prediction analysis done studying grain size derived bedload calculating total discharge velocity gradient ratio understanding history evolutionary changes recent times typical locations seeing these stretch arid semiarid zones having little vegetation cover displaying clear uniformity dimension parameters therefore easily spotted helping identify right kind location suited specific purpose usage conservation recreation management oil gas resources irrigation projects building construction engineering works lumber services tourism activities relying information obtain direct observation field studies aerial photographs topographic maps exploratory drilling detailed core sampling comprehensive data pinpoint exact spot project executed safely securely planned professional manner ensuring minimal disruption environment concerned everyday lives people residing region affected positively impacting economies growth sustaining societies values customs traditions passed generations benefiting mankind whole established infrastructure metropolis entails multiple avenues enrich cultural heritage society sustain vitality dealing current threats pollution climate change hoping achieve zero carbon footprint future prosperity all stakeholders included preservation natures riches bounty Lastly contamination groundwater sources serious issue encountered effect health population specially drinking wells toxic chemicals leaked underground aquifers polluting sources carcinogenic agents heavy metals radioactive materials pesticides detergents petroleum products hazardous disposal sites leaks pipelines sewage industrial wastewater production plants seepages occurring contaminated surface runoffs infiltrating soils reaching depths below surface oozing affecting inhabitants surrounding villages aquitards confining layers nonpermeable strata blocking fast migrating contaminants penetrating deep deposits areas should monitored regulated accordingly take preventive measures mitigate damages inflicted reduce risk exposure citizens drinking supplies intervene authorities regulate practices air soil protection ensure cleaned filtered treated necessary fully protect public health welfare government laws regulations enforceable responsibility implementation lies governing bodies play role safeguarding rights citizens real sense taking conscious effort protect natural resources promote sustainable industries wealth countries nations world strive better standards living progress technical advances made enhancing productivity profitability businesses increasing incomes comfort lifestyles focus proper waste treatment recycling initiatives abolish use synthetic harmful toxins inspire organic farming organic methods generation biogas green technologies renewable resources aimed reducing environmental impact conserving scarce dwindling supplies optimizing utilization protecting minimizing abuse exploitation managed efficiently bringing lasting positive socio economic impacts communities involved making safer healthier secure generations come pass