Physical Geography Exam 3 Study Guide

Richter scale

(1935): amplitude of waves • Log-scale: every unit = 10x increase in wave amplitude; 31.5x increase in energy release 1. Open, ended logarithmic scale that estimates magnitude based on measurement of the maximum seismic wave amplitude; designed by Charles Richter in 1935; now replaced by moment magnitude scale.

moment magnitude scale

(1993): accurate for large EQ • Size of (sub)surface area rupture, fault slippage, nature of materials faulted, ground acceleration 1. An earthquake magnitude scale. Considers the amount of fault slippage, the size of the area that ruptured, and the nature of the materials that faulted in estimating the magnitude of an earthquake--an assessment of the seismic moment. Replaces Richter scale; especially valuable in assessment in larger-magnitude events.

orogenesis

(Mountain Building) Types of Orogenies: 1. Ocean-Continent: Andes & Rockies 2. Ocean-Ocean: Volcanic arcs (Japan, Indonesia) 3. Continent-Continent: Himalaya & Alps • ocean/ocean/continent-->thermal • continent/continent-->mechanical Def- geologic term for mountain building · Literally means "birth of mountains" · Orogeny- A mountain building episode, occurring over million of years, usually caused by large-scale deformation and uplift of the crust

plateau basalts

(flood basalts) formed volcanic strata now exposed by rivers throughout the region 1.

littoral zone

(latin shore); highest water line (onshore)-->water too deep for waves to move sediment on ocean floor (60m depth) A specific coastal environment; that region between the high-waterline during a storm and a depth at which storm waves are unable to move seafloor sediments.

wave refraction

---waves work to straighten coastlines-->bending of waves(headlands with resistant topography)-->wave energy not equally distributed (erosion potential varies) 1. A bending process that concentrates wave energy on headlands and disperses it in coves and bays; the long-term result is coastal straightening.

Coral Bleaching

--color-->white (death of red-brown to green - no nutrient supply); warming of SSTs (1-2oC) 1.a phenomenon affecting coral reefs by which they lose their natural color as a result of high water temperatures or other environmental stressors such as pollutants

desert pavement

--concentrates large rock fragments, ~ cobblestone 1. On arid landscapes, a surface formed when wind deflation and sheetflow remove smaller particles, leaving residual pebbles and gravels to concentrate at the surface; an alternative sediment-accumulation hypothesis explains some desert pavements; resembles a cobblestone street.

Coral Reefs

--formed by constantly expanding live corals at ocean. 1. Simple cylindrical marine animal with a saclike body that secretes calcium carbonate to form a hard external skeleton and, cumulatively, landforms called reefs; lives symbiotically with nutrient-producing algae; presently in a worldwide state of decline due to bleaching (loss of algae A ridge of rock in the sea formed by the growth and deposit of coral.

surface creep

--impact of grains pushing other larger particles forward (20% of transport) 1. A form of eolian transport that involves particles too large for saltation; a process whereby individual grains are impacted by moving grains and slide and roll.

periglacial

--processes, landforms, topography associated with glacially adjacent areas (past/present)-->20% Earth's surface 1. Cold-climate processes, landforms, and topographic features along the margins of glaciers, past and present; periglacial characteristics exist on more than 20% of Earth's land surface; includes permafrost, frost action, and ground ice.

beach

--sediment in motion, deposited by waves and currents quartz (black-sand - volcanically derived - Iceland, Hawaii) • shingle beaches: pebbles/cobbles (e.g. southern France) • beaches stabilize shorelines ! absorb/dissipate wave energy • beach/longshore drift ! coastline in constant state of flux • control strategies: jetties, groin, breakwater 1. The portion of the coastline where an accumulation of sediment is in motion.

eolian

--wind • Eolian - work carried out by wind (Greek Aeolusgod of wind) • Wind - geomorphic agent of erosion, transportation, deposition (~ water) • Eolian Depositional Landforms • Loess Deposits 1. Caused by wind; refers to the erosion, transportation, and deposition of materials; spelled Aeolian in some countries. 2 major processes: - deflation: loose particles (lift/loosen) - abrasion: sandblasting (grinding)

circum-Pacific belt, Ring of Fire

1. 2. A tectonically and volcanically active region encircling the Pacific Ocean; also known as the circum-Pacific belt.

wash, playa, bajada

1. 2. closed drainage, intermittently wet/dry An area of salt crust left behind by evaporation on a desert floor, usually in the middle of a desert or semiarid bolson or valley; intermittently wet and dry. 3. continuous apron (coalesced fans) A continuous apron of coalesced alluvial fans, formed along the base of mountains in arid climates; presents a gently rolling surface form fan to fan.

Focus, Epicenter, Foreshock, Aftershock

1. (Hypocenter): subsurface; earthquake initiated Subsurface area where the motion of seismic waves is initiated along the fault plane 2. the area a the surface directly above the focus 3. Shake after main quake a quake that precedes the main shock 4. preceding the main shock occurs after the main shock, sharing the same general area of the epicenter; some rival the main tremor in magnitude

longshore current, beach drift

1. (littoral current): waves arrive at shore at oblique angle-->slows and flows parallel to coast-->transports large amounts of sediment (longshore drift-surf zone), dependent on wind/wave direction A current that forms parallel to a beach as waves arrive at an angle to the shore; generated in the surf zone by wave action, transporting large amounts of sand and sediment. 2. swash/backwash Material, such as sand, gravel, and shells, that is moved by the longshore current in the effective direction of the waves.

cinder cone, caldera

1. < 450 m, cone shaped hill A volcanic landform of pyroclastics and scoria, usually small and cone-shaped and generally not more than 450 m (1500 ft) in height, with a truncated top. 2. large basin shaped depression An interior sunken portion of a composite volcano's crater; usually steep-sided and circular, sometimes containing a lake; also can be found in conjunction with shield volcanoes.

brine, brackish

1. > 35%, Seawater with a salinity of more than 35% for example, the Persian Gulf. 2. <35%, Seawater with a salinity of less than 35% for example, the Baltic Sea.

chemical weathering: spheroidal, hydration, hydrolysis, oxidation, carbonation

1. A chemical weathering process in which the sharp edges and corners of boulders and rocks are weathered in thin plates that create a rounded, spheroidal form. 2. A chemical weathering process involving water that is added to a mineral, which initiates swelling water and stress within the rock, mechanically forcing grains apart as the constituents expand. 3. A chemical weathering process in which minerals combine with water; a decomposition process that causes silicate minerals in rocks to break down and become altered. 4. A chemical weathering process in which oxygen dissolved in water oxidizes (combines with) certain metallic elements to form oxides; most familiar is the "rusting" of iron in a rock or soil (Ultisols, Oxisols), which produces a reddish-brown stain of iron oxide. 5. A chemical weathering process in which weak carbonic acid (water and carbon dioxide) reacts with many minerals that contain calcium, magnesium, potassium, and sodium (especially limestone), transforming them into carbonates.

ice sheet, ice cap, ice field

1. A continuous mass of unconfined ice, covering at least 50,000 km^2 (19,500 mi^2). The bulk of glacial ice on Earth covers Antarctica and Greenland in two ice sheets. 2. circular, < 50,000 sq km, buries underlying landscape A large, dome-shaped glacier, less extensive than an ice sheet, although it buries mountain peaks and the local landscape; generally, less than 50,000 km^2 (19,300 mi^2) 3. not as extensive, elongated shape (linear), e.g. Patagonia The least extensive form of a glacier, with mountain ridges and peaks visible above the ice; less than an ice cap or ice sheet.

barrier spit, bay barrier

1. A depositional landform that develops when transported sand or gravel in a barrier beach or island is deposited in long ridges that are attached at one end to the mainland and partially cross the mouth of a bay. --long ridge extending out across mouth of bays (sand); e.g. Cape Cod 2. An extensive barrier spit of sand or gravel that encloses a bay, cutting it off completely from the ocean and forming a lagoon; produced by littoral drift and wave action; sometimes referred to as a baymouth bar. --cuts bay off completely (lagoon formation); material generally transported by littoral drift (beach/longshore combined)

delta, estuary

1. A depositional plain formed where a river enters a lake or an ocean; named after the triangular shape of the Greek letter delta. • mouth of river reaches base-level (large body of water)-->decrease in v (transported load > capacity)-->sediments deposited (coarse-->fine) 2. The point at which the mouth of a river enters the sea, where freshwater and seawater are mixed; a place where tides ebb and flow.

floodplain

1. A flat, low-lying area along a stream channel, created by and subject to recurrent flooding; alluvial deposits generally mask underlying rock. --flat, low-lying area subject to flooding-->flooding overtops banks, decrease v, deposits increasingly fine grained sediment further away from channel (natural levee)-->perched channels

hydrograph

1. A graph of stream discharge (in m^3/s or ft^3/s) over a period of time (minutes, hours, days, years) at a specific place on a stream. The relationship between stream discharge and precipitation input is illustrated on the graph. ---stream Q over time-->relates ppt input and stream Q • base-flow: dry season, low water flow (groundwater input) • peak-flow: ppt event in watershed; f(x) amount, location and duration of event and surface characteristics in watershed

oxbow lake

1. A lake that was formerly part of the channel of a meandering stream; isolated when a stream eroded its outer bank, forming a cutoff through the neck of the looping meander. In Australia, known as a Billabong. • erodes outer bank (neck)-->neck narrows-->erodes, forms cutoff-->isolated from channel !stream becomes straighter

natural levees, yahzoo tributary, backswamp

1. A long, low ridge that forms on both sides of a stream in a developed floodplain; a depositional product (coarse gravels and sand) of river flooding. 2. Any tributary stream that runs parallel to, and within the floodplain of a larger river for considerable distance, before eventually joining it. This is especially the characteristic when such a stream is forced to flow along the base of the main river's natural levee.[1] Where the two meet is known as a 'belated' confluence or a 'deferred' junction. The name comes from the Yazoo River, which runs parallel to the Mississippi River for 280 km (170 mi) before converging,[2] being constrained from doing so upstream by the river's natural and man-made levees. --found in floodplain 3. The section of a floodplain where deposits of fine silts and clays settle after a flood. Backswamps usually lie behind a stream's natural levees. --found in floodplain

tides: flood, ebb, spring, neap tides

1. A pattern of twice-daily oscillations in sea level produced by astronomical relations among the sun, the moon, and the Earth; experienced in varying degrees around the world. ---gravitational force greater on near side and inertia stronger on far side-->difference in strength of these forces creates TIDES • conjunction: sum of gravitational forces-->large tidal bulge (near side); far side (bulge due to inertia) • Earth's rotation makes tides appear to move in/out of shore (tidal bulges relatively fixed)-->daily rotate through two high (flood) tides and two low (ebb) tides (difference is tidal range) 2. high tide/Incoming or rising tide 3. low tide/ falling or retreating tide 4. gravitational forces strongest in Sun/Moon conjunction alignment or Sun/Moon in opposition A tide that occurs when the difference between high and low tide is greatest. Come twice a month, approximately at the full and new moon. occur when the sun and moon are directly in line with the earth and their gravitational pulls reinforce each other. 5. gravitational forces offset; limit tidal range A tide just after the first or third quarters of the moon when there is the least difference between high and low water. occur when the sun, earth, and moon form a right angle and the gravitational pull of the sun counteracts the pull of the moon.

soil creep, scarification

1. A persistent, gradual mass movement of surface soil o Individual soil particles are lifted and disturbed A persistent mass movement of surface soil where individual soil particles are lifted and disturbed by the expansion of soil moisture as it freezes or by grazing livestock or digging animals. 2. Human-induced mass movement of sediment, soil, and rock material, such as large-scale open-pit mining and strip mining Human-induced mass movement of Earth movement of Earth Materials, such as large-scale open-pit mining and strip mining.

geomagnetic reversal

1. A polarity change in Earth's Magnetic field. With uneven regularity, the magnetic field fades to zero and then returns to full strength, but with the magnetic poles reversed. Reversals have been recorded nine times during the past 4 million years.

stratigraphy

1. A science that analyzes the sequence, spacing, geophysical, and geochemical properties, and spatial distribution of rock strata. • Examples of time clues- fossils, remains of ancient sea plants and animals · Absolute - uses radioactive decay of isotopes (K.Ar, 14C, 210-Pb) o Numerical age o Determined most often using isotopic dating techniques Technique of Radiometric Dating- uses the rate of decay for different unstable isotopes to provide a steady time clock

tarns, paternoster lakes

1. A small mountain lake, especially one that collects in a cirque basin behind risers of rock material or in an ice-gouged depression. 2. one of a series of glacial lakes connected by a single stream or a braided stream system. occur in alpine valleys

isostasy

1. A state of equilibrium in Earth's crust formed by the interplay between portions of the less-dense lithosphere and the more-dense asthenosphere and the principle of buoyancy. The crust depresses under weight and recovers with its removal-- for example, with the melting of glacial ice. The uplift is known as isostatic rebound . state of gravitational equilibrium between Earth's crust and mantle such that the crust "floats" at an elevation that depends on its thickness and density of underlying roots of the low density of the mountain.

undercut bank, point bar

1. A steep bank formed along the outer portion of a meandering stream; produced by lateral erosive action of a stream; sometimes called a cutbank. • outer portion of each meander (high v, scouring action) 2. In a stream, the inner portion of a meander, where sediment fill is redeposited. • low v-->sediment deposited; migrate downstream (landscape)

flash flood

1. A sudden and short-lived torrent of water that exceeds the capacity of a stream channel; associated with desert and semiarid washes.

traction, saltation

1. A type of sediment transport that drags coarser materials along the bed of a stream. 2. The transport of sand grains (usually larger than .2mm, or .008 in.) by stream or wind, bouncing the grains along the ground in asymmetrical paths.

effusive eruption, shield volcano

1. A volcanic eruption characterized by low-viscosity basaltic magma and low-gas content. which readily escapes. Lava pours forth onto the surface with relatively small explosions and few pyroclastics; with relatively small explosions and few pyroclastics; tends to form shield volcanoes. 2. A symmetrical mountain landform built from effusive eruptions (low-viscocity magma); gently sloped and gradually rising from the surrounding landscape to a summit crater; typical of the Hawaiian Islands. gentle, slow production of lava (Iceland, Hawaii; sea floor) • Low viscosity, dark basalt, gases escape (low viscosity)-->pours onto surface, minimally explosive • Kilauea-->longest episode (20 years) • Shield volcano - gently sloped ! summit crater; height: gradual accretion of lava • Flood basalts - extensive sheets of basalt; e.g. Columbia Plateau (2-3 km thick), Deccan Plateau (India)

rockfall, debris avalanche, landslide, mudflows

1. A volume of rock that falls through the air and hits a surface o Individual pieces fall independently and characteristically form piles of irregular broken rock called talus. Free-falling movement of debris from a cliff or steep slope, generally falling straight or bounding downslope. 2. A mass of falling and tumbling rock, debris, and soil; Can be dangerous because of the tremendous velocities achieved by the onrushing materials. 3. A sudden rapid downslope movement of a cohesive mass of regolith and/or bedrock in a variety of mass-movement forms under the influence of gravity; a form of mass movement. 4. Fluid downslope flows of material containing more water than earthflows.

continental drift, Pangaea

1. Alfred Wegener (1880-1930) • continental crusts light, ocean floor dense • matching glacial deposits in Brazil, South Africa, India, Australia • shape of continents, geology, fossils suggest close past proximity • Geodetic measurements in Greenland indicated movement 2. theory that once all the continents were joined in a super-continent, which scientists call Pangaea. Over a vast period of time, the continents drifted apart to their current locations. Alfred Wegener first supported continental drift.

lagoon, tombolo

1. An area of coastal seawater that is virtually cut off from the ocean by a bay barrier or barrier beach; also, the water surrounded and enclosed by an atoll. 2. A landform created when a coastal sand deposits connect the shoreline with an offshore island outcrop or sea stack. --sediment deposits connecting coastline to off-shore island or sea stack

mantle, asthenosphere, crust

1. An area within the planet representing about 80% of Earth's total volume, with densities increasing with depth and averaging 4.5g/cm3, occurs between the core and the crust; is rich in iron and magnesium oxides and silicates. • Guttenberg discontinuity • 80% of Earth's volume • rich: FeO, MgO,SiO2 • transition zone: 670 km • athenosphere: 70-250 km 2. Region of the upper mantle just below the lithosphere; the least rigid portion of Earth's interior and known as the plastic layer, flowing very slowly under extreme heat and pressure. 3.• crust + uppermost mantle (70 km) • Moho discontinuity • thickness: continent vs ocean crust Earth's outer shell of crystalline surface rock, ranging from 5 to 60 km (3 to 38 mi) in thickness from oceanic crust to mountain ranges. Average density of continental crust is 2.7g/cm3, whereas oceanic crust is 3.0g/cm3. • Makes up only a fraction of Earth's overall mass and only a small portion of the overall distance from Earth's center to its surface •Crustal areas beneath mountain masses are thicker • Just 8 natural elements make up over 98% of Earth's crust by weight (oxygen and silicon) Oxygen = 46% in crust and 21% in atmosphere

uniformitarianism, superposition

1. An assumption that physical processes active in the environment today are operating at the same pace and intensity that have characterized them throughout geologic time; proposed by Hutton and Lyell. •Rocks and unconsolidated particles are arranged with the youngest layers "superposed" toward the top of a rock formation and the oldest at the base •This principle holds true as long as the materials have remained undisturbed 2. a basic law of geochronology, stating that in any undisturbed sequence of rocks deposited in layers, the youngest layer is on top and the oldest on bottom, each layer being younger than the one beneath it and older than the one above it. •Physical processes operating today that operated in the past •Hutton and Lyell: "present is key to the past" Applies mainly to the gradual processes of geologic change, but also includes sudden catastrophic events like landslides and earthquakes

pyroclastics, aa, pahoehoe

1. An explosively ejected rock fragment launched by a volcanic eruption; sometimes described by the more general term tephra. 2. Rough, Jagged and clinker basaltic lava with sharp edges. This texture is caused by the loss of trapped gases, a slow flow, and the development of a thick skin that crack into a jagged surface. 3. Basaltic lava that is more fluid than aa. Forms a thin crust that forms folds and appears "ropy', like coiled, twisted rope

lateral moraine, medial moraine, terminal moraine

1. Debris transported by a glacier that accumulates along the sides of the glacier and is deposited along these margins. side of glacier 2. Debris transported by a glacier that accumulates down the middle of the glacier, resulting from two glaciers merging their lateral moraines; forms a depositional feature following glacial retreat. center where 2 glaciers join 3. Eroded debris that is dropped at a glacier's farthest extent. end: furthest/still-stand of glacier-->all unsorted/stratified

erosion, transport, deposition

1. Denudation by wind, water, or ice, which dislodges, dissolves, or removes surface material. 2. 3. The process whereby weathered, wasted, and transported sediments are laid down by air, water and ice.

col, horn

1. Formed by two headward-eroding cirques that reduce an arête(ridge crest) to form a high pass or saddle-like narrow depression. 2. A pyramidal, sharp-pointed peak that results when several cirque glaciers gouge an individual mountain summit from all sides.

mass movement, wasting

1. Is the downslope movement of a body of material made up of soil, sediment, or rock propelled by the force of gravity. All unit movements of materials propelled by gravity; can range from dry to wet, slow to fast, small to large, and free-falling to gradual or intermittent. 2.

loess

1. Large quantities of fine-grained clays and silts left as glacial outwash deposits; subsequently blown by the wind great distances and redeposited as a generally unstratified, homogeneous blanket of material covering existing landscapes; In China loess originated from desert lands.

alluvial terraces

1. Level areas of that appear as topographic steps above a stream, created by the stream as it scours with renewed downcutting into its floodplain; composed of unconsolidated alluvium. • tectonic uplift (rejuvenation)-->leads to increased downcutting and entrenchment • alluvial terraces - step-like; paired at similar elevations • originally depositional feature (floodplain)--> eroded as stream changes in load and capacity

barrier beaches, barrier islands

1. Narrow, long, depositional feature, generally composed of sand, that forms offshore roughly parallel to the coast; may appear as barrier islands and long chains of barrier beaches. 2. Generally, a broadened barrier beach offshore. --form parallel to coastline, formed from sand-->barrier beaches/islands (e.g. North Carolina's Outer Banks; along Gulf and Atlantic coasts) • landward side: tidal flats, marshes, swamps, lagoons, coastal dunes, beaches • origin of barrier islands not certain-->undersea ridges • migrating landward-->unwise to build upon, brunt of storm of energy, e.g. Hugo (SC)

sinkholes, caves and caverns

1. Nearly circular depression created by the weathering of Karst landscapes with subterranean drainage: also known as a doline in traditional studies; may collapse through the roof of an underground space. 2. Natural underground areas large enough for humans to enter o Form in limestone because it is so easily dissolved by carbonation 3. Any large cave formed by chemical processes o Largest in Us: Mammoth Cave in KY, Carlsbad in New Mexico, and Lehman Cave in Nevada

physical weathering: frost action, talus, salt crystal growth, exfoliation

1. Repeated freezing (expanding) and thawing (contracting) of water is this, which breaks rocks apart in the process of frost wedging 2. 3. As crystals accumulate and grow, they exert a force great enough to separate the grains making up the rock and begin breaking the rock to pieces, a process known as SCG 4. The process whereby rock peels or slips off in sheets instead of breaking up into grains (can be arch shaped or dome shaped)

firn, glacial ice, firn line

1. Snow of a granular texture that is transitional in the slow transformation form snow to glacial ice; snow that has persisted through a summer season in the zone of accumulation. 2. A hardened form of ice, very dense in comparison to normal snow or firn. 3. The snow line that is visible on the surface of a glacier, where winter snows survive the summer ablation season; analogous to a snow line on land.

fluvial, hydrology

1. Stream-related processes; from the Latin word Fluvius for "river" or "running water". 2. Hydrology: science of water (circulation, distribution, properties) The science of water, including its global circulation, distribution, and properties--specifically water at and below Earth's surface. 3 processes: erosion, transportation and deposition

Mohorovičić discontinuity (Moho)

1. The Boundary between the crust and the rest of the lithospheric upper mantle; named for the Yugoslavian seismologist Mohorovicic; a zone of sharp material and density contrasts.

drainage basin, watershed, continental divides

1. The basic spatial geomorphic unit of a river system; distinguished from a neighboring basin by ridges and highlands that form divides, marking the limits of the catchment area of the drainage basin. 2. An area or ridge of land that separates waters flowing to different rivers, basins, or seas. 3. A ridge or elevated area that separates drainage on a continental scale; specifically, that ridge in North America that separates drainage to the Pacific Ocean on the west side from drainage to the Atlantic Ocean and the Gulf of Mexico on the east side and to Hudson Bay and the Arctic Ocean in the north.

gradient, graded stream

1. The drop in elevation from a stream's headwaters to its mouth, ideally forming a concave slope. 2. An idealized condition in which a stream's load and the landscape mutually adjust. This forms a dynamic equilibrium among erosion; transported load, deposition, and the stream's capacity. balance (dynamic equilibrium) btw erosion, transportation, and deposition

aggradation, braided stream

1. The general building of land surface because of deposition of material; opposite of degradation. When the sediment load of a stream exceeds the stream's capacity to carry it, the stream channel becomes filled through this process. 2. • braided stream - reduced Q (reduces transport ability); landslides, glacial meltwater A stream that becomes a maze of interconnected channels laced with excess sediment. Braiding often occurs with a reduction of discharge that reduces a stream's transporting ability or with an increase in sediment load.

Stream Gradient

1. The grade measured by the ratio of drop in elevation of a stream per unit horizontal distance, usually expressed as feet per mile or metres per kilometre. --elevation decline over distance from headwaters to mouth; concave shape

nickpoint

1. The point at which the longitudinal profile of a stream is abruptly broken by a change in gradient; for example, a waterfall, rapids, or cascade. abrupt change in gradient (e.g. waterfall) • potential energy-->kinetic energy: eliminate nickpoint (geology) • waterfall - water in freefall ! erosion at base-->undercuts, collapse and shift upstream • waterfall -->series of rapids • Niagara Falls - 11km retreat from the Niagara Escarpment in 12,000

weathering, regolith, bedrock, parent material

1. The process by which surface and subsurface rocks disintegrate, or dissolve, or are broken down. Rocks at or near Earth's surface are exposed to physical and chemical weathering processes. 2. Partially weathered rock overlying bedrock, whether residual or transported. 3. The rock of Earth's crust that is below the soil and is basically unweathered; such solid crust sometimes is exposed as an outcrop. 4. The unconsolidated material, from both organic and mineral sources. that is the basis of soil development.

angle of repose

1. The steepness of the resulting slope; depends on the size and texture of the grains -- Represents a balance of the driving force (gravity) and the resisting force (friction and shear)

folding, faulting

1. When convergent plate boundaries intensely compress rocks and deform them The bending and deformation of beds of rock strata subjected to compressional forces. 2.Rocks on either side of the fracture (caused by stress) displace relative to the other side The process whereby displacement and fracturing occur between two portions of Earth's crust; usually associated with Earthquake activity.

dune, erg desert, sand sea

1. accumulation of sand shaped by wind (quartz) A depositional feature of sand grains deposited in transient mounds, ridges, and hills; extensive areas of sand dunes are called sand seas. 2. extensive area of dunes; e.g. Grand Erg Oriental (Sahara) An extensive area of sand and dunes; from the Arabic word for "dune field". 3. An extensive area of sand and dunes; characteristic of Earth's erg deserts. angle of repose: steepest angle at which slope is stable (30-34o) • avalanche slope: constant addition of sand allows it to tumble down from crest-->continues to migrate

kettle, kame

1. block of ice deposited on outwash plain following glacier retreat (Walden Pond) Forms when an isolated block of ice persists in a ground moraine, an outwash plain, or a valley floor after a glacier retreats; as the block finally melts, it leaves behind a steep-sided hole that frequently fills with water. 2. A depositional feature of glaciation; a small hill of poorly sorted sand and gravel that accumulates in the crevasses or in ice-caused indentations in the surface.

dissolved load, suspended load, bed load

1. chemical weathering - limestone, soluble salts) Materials carried in chemical solution in a stream, derived from minerals such as limestone and dolomite or from soluble salts. 2. fine-grained clasts; flowing water Fine particles held in suspension in a stream. The finest particles are not deposited until the stream velocity nears zero. 3.• bed load - coarse material dragged along streambed: traction; rolled or bounced: saltation Coarse materials that are dragged along the bed of a stream by traction or by the rolling and bouncing motion saltation; involves particles too large to remain in suspension.

San Andreas fault

1. fault line that extends for about 600 miles (965 km) through the length of coastal California. Seismic activity is common along its course, caused by friction between two crustal plates sliding past each other along the line of the fault. --is a transform fault.

till plain, outwash plains

1. forms behind end/terminal moraine (unstratified); A large, relatively flat plain composed of unsorted glacial deposits behind a terminal or end moraine. Low-rolling relief and unclear drainage patters are characteristic. 2.stratified drift Area of glacial stream deposits of stratified drift with meltwater-fed, braided, and overloaded streams; occurs beyond a glacier's morainal deposits.

Depositional Landforms Created by Alpine Glaciation

1. glacial drift: sorted by glacial meltwater (stratified drift);unstratified/sorted (till) 2. glacial erratics: foreign in composition/origin from where deposited 3. moraines: depositional landform (glacial sediment); lateral: side of glacier; medial: center where 2 glaciers join; terminal/end: furthest/still-stand of glacier-->all unsorted/stratified

igneous rock: magma, lava, pluton, batholith

1. it has solidified and crystallized from a hot molten state (either magma or lava). 2.molten rock below surface (intrusive vs extrusive) • cooling rate-->crystalline properties (fine vs coarse grained) • intrusive igneous-->pluton (penetrates crustal rock); batholith (largest pluton form: 100 sq km) • sills (parallel) vs. dikes (perpendicular) • basalt - extrusive igneous rock (oceanic crust) • Classifying igneous rocks-->mineral composition/texture • felsic (feldspar and silica) vs mafic (magnesium and ferric) • obsidian - volcanic glass; magma: Molten rock from beneath Earth's surface; fluid; gaseous; under tremendous pressure, and either intruded into existing crustal rock or extruded onto the surface as lava. 3. Magma that issues from volcanic activity onto the surface; the extrusive rock that results when magma solidifies. 4. A mass of intrusive igneous rock that has cooled slowly in the crust; forms in any size or shape. The largest partially exposed plution is a batholith. 5. The largest plutonic form exposed at the surface; an irregular intrusive mass; it invades crustal rocks, cooling slowly so that large crystals develop.

metamorphic rock: marble, gneisis, slate

1. it is existing igneous and sedimentary rock that has undergone profound physical and chemical changes under increased pressure and temperature. Constituent mineral structures may exhibit foliated or nonfoliated textures. 2. A hard crystalline metamorphic form of limestone, typically white with mottlings or streaks of color, that is capable of taking a polish and is used in sculpture and architecture. 3. A metamorphic rock with a banded or foliated structure, typically coarse-grained and consisting mainly of feldspar, quartz, and mica. 4. A fine-grained gray, green, or bluish metamorphic rock easily split into smooth, flat pieces

slipface

1. leeward steeper The lee side of a dune where the slope approximates the angle of rest of loose sand that is generally about 33 degrees

sedimentary rocks: lithification, limestone, sandstone, shale

1. lithification, limestone, sandstone, shale 2. The compaction, cementation, and hardening of sediments into sedimentary rock. 3. Most common chemical sedimentary rock (nonclastic); Lithified calcium carbonate (CaCO3); very susceptible to chemical weathering by acids in the environment, including carbonic acid in rainfall. 4. Sandstone: (sand), sedimentary rock consisting of sand or quartz grains cemented together, typically red, yellow, or brown in color. 5. Shale: 2 types of (mudstone), soft, finely stratified sedimentary rock that formed from consolidated mud or clay and can be split easily into fragile slabs. sedimentary rocks: • Clastic (transported bits of former rock) - Table 11.3: clast sizes • Chemical (dissolved minerals) - Limestone - lithified CaCO3 - Dolomite - CaMgCO3 - Evaporites - salts (gypsum, NaCl) - Travertine (CaCO3) - hydrotherrmal activity

deflation, abrasion

1. loose particles A process of wind erosion that removes and lifts individual particles, literally blowing away unconsolidated, dry, or noncohesive sediments. 2. sandblasting (grinding) Mechanical wearing and erosion of bedrock accomplished b the rolling and grinding of particles and rocks carried in a stream, removed by wind in a "sandblasting" action, or imbedded in glacial ice. • sandblasting by wind-blown grains • rate of abrasion: f(x) of hardness of surface rocks, wind velocity, constancy • usually limited to w/in 1-2 m of ground • pitted, grooved or polished with aerodynamic shaped (prevailing wind direction)

esker

1. narrow, sinuous ridge coarse sand/gravel-->forms beneath glacial in meltwater stream (quarries) A sinuously curving, narrow deposit of coarse gravel that forms along a meltwater stream channel, developing in a tunnel beneath a glacier.

explosive eruption, composite volcano

1. o Formed by violent explosions of magma, gas, and pyroclastics driven by the buildup of pressure in magma o Occurs because magma produced by the melting of subducted oceanic plate and other materials is thicker than magma that forms effusive volcanoes A violent and unpredictable volcanic eruption, the result of magma that is thicker (more viscous), stickier, and higher in has and silica content than that of an effusive eruption; tends to form blockages within a volcano; produces composite volcanic landforms. 2. Muntain produced by a series of explosive eruptions; formed by multiple layers of lava, ash, rock and pyroclastics § Sometimes called stratovolcanoes A volcano formed by a sequence of explosive volcanic eruptions; steep-sided and conical in shape; sometimes referred to as a stratovolcano, although composite is the preferred term.

normal, reverse, thrust fault, strike-slip fault

1. pulling rocks apart (tension fault) hanging wall - downward drop footwall block - raised side Type of geologic fault in rocks. Tension produces strain that breaks a rock, with one side moving vertically relative to the other side along an inclined fault plane. 2. compression pushing rocks (thrust fault); < landslide probability; Los Angeles (Northridge) Compressional forces produce strain that breaks a rock so that one side moves upward relative to the other side. 3. Reverse fault where the fault plane forms a low angle relative to the horizontal; an overlying block moves over an underlying block. 4. horizontal movement along fault plane; ight-lateral vs. left-lateral linear Rift Valleys(SA Fault; NA and Pacific plate) Horizontal movement along a fault line--that is, movement in the same direction as the fault. Such movement is described as right lateral or left lateral, depending on the relative motion observed across the fault.

anticline, syncline

1. ridge of a fold, slope downward away from axis 2. trough of fold, slope downward toward the axis

ventifacts, yardangs

1. rocks bearing evidence of eolian erosion A piece of rock etched and smoothed by eolian erosion---that is, abrasion by windblown particles. 2. elongated ridges/formations of eroded, streamlined rock-->abrasion (windward), deflation (leeward) A streamlined rock structure formed by deflation and abrasion; appears elongated and aligned with the most effective wind direction.

glacial drift, stratified drift

1. sorted by glacial meltwater (stratified drift) General term for all glacial deposits, both unsorted (till) and sorted (stratified drift). 2. Sediments deposited by glacial meltwater that appear sorted; a specific form of glacial drift.

till, moraine

1. sorted by glacial meltwater (stratified drift) General term for all glacial deposits, both unsorted (till) and sorted (stratified drift). 2. Sediments deposited by glacial meltwater that appear sorted; a specific form of glacial drift.

volcano, crater

1. structure in the Earth's crust containing an opening at the end of a central vent or pipe through which magma rises from the asthenosphere and upper mantle A mountainous landform at the end of a magma conduit, which rises from below the crust and vents to the surface. Magma rises and collects in a magma chamber deep below, erupting effusively or explosively and forming composite, shield, or cinder-cone. o Active: one that has erupted at least once in recorded history 2. forms new summit (depression)

Erosional and Depositional Features Created by Continental Glaciation

1. valley train: sorted/stratified material carried further out from terminal moraine-->rock flour --different landscape of formation (broad, flat low-lying areas) 2. till plain: forms behind end/terminal moraine (unstratified); 3. outwash plains: stratified drift 4. esker: narrow, sinuous ridge coarse sand/gravel-->forms beneath glacial in meltwater stream (quarries) 5. kettle: block of ice deposited on outwash plain following glacier retreat (Walden Pond) • streamlined hills: • drumlins -- deposited till shaped in direction of ice movement (blunt upstream; tapered end downstream), NY, WI, ON • roche moutonnée - gentle slope upstream side, polished; downstream steep, rugged

sea-floor spreading, mid-ocean ridges

1. • sea floor spreading-->undersea mountain ranges (64 km X 1km)-->1960s As proposed by Hess and Dietz, the mechanism driving the movement of the continents; associated with upwelling flows of magma along the worldwide system of mid-ocean ridges 2. • mid-ocean ridges: upwelling magma-->crust fractures, spreads and cools • magnetic reversals - particles align themselves with prevailing magnetic field • youngest crust-->spreading center; oldest oceanic crust at subduction zones (208 mya) A submarine mountain range that extends more than 65,000 km (40,000 mi) worldwide and averages more than 1000 km (600 mi) in width; centered along sea-floor spreading centers.

continental shields

1. •region where craton is exposed at the surface ◦craton = nucleus of continent/landmass Generally, old, low-elevation heart-land regions of continental crust; various cratons (granitic cores) and ancient mountains are exposed at the surface.

granite, basalt

1.A coarse-grained (slow-cooling) intrusive igneous rock of 25% quartz and more than 50% potassium and sodium feldspars; characteristic of the continental crust. 2. A common extrusive igneous rock, finegrained, comprising the bulk of the ocean- floor crust, lava flows, and volcanic forms; gabbro is its intrusive form.

minerals, rocks, rock cycle

1.An element or combination of elements that forms an inorganic natural compound; described by a specific formula and crystal structure. • 8 natural elements 99% of Earth's crust • mineral - inorganic natural compound, specific chemical formula, crystalline structure--> e.g. Quartz • silicates: common mineral family-->e.g. quartz, feldspar, clay minerals, gemstones • oxides: oxygen + metallic elements-->e.g. hematite (Fe2O3) • carbonates: carbon + oxygen + metals (Ca, Mg, K) ! e.g. calcite (CaCO3) 2.assemblage of minerals bound together (granite); mass of single mineral (rock salt); undifferentiated material (volcanic glass); solid organic matter (coal) • 3 major rock types: • igneous • sedimentary • metamorphic

seismic waves, core

1.Earthquakes/Nuclear Tests 2. The deepest inner portion of Earth, representing one-third of its entire mass; differentiated into two zones-- a solid-iron inner core surrounded by a dense, molten, fluid metallic-iron outer core. • 1/3rd mass (1/6th volume) • inner core (solid Fe/Iron) • outer core (molten Fe/Iron) • magnetism - fluid core, • geomagnetic reversals

sheetflow

1.thin sheet of water (flowing downslope) Surface water that moves downslope in a thin film as overland flow; not concentrated in channels larger than rills.

hydraulic action, abrasion

1.work done by flowing water alone (squeeze-release action: loosens and lifts rocks)-->further erosion of streambed: (mechanically) abrasion The erosive work accomplished by the turbulence of water; causes a squeezing and releasing action in joints in bedrock; capable of prying and lifting rocks. 2. Mechanical wearing and erosion of bedrock accomplished by the rolling and grinding of particles and rocks carried in a stream, removed by the wind in a "sandblasting" action, or imbedded in glacial ice.

waves, swells, breaker

5. gravitational forces offset; limit tidal range A tide just after the first or third quarters of the moon when there is the least difference between high and low water. occur when the sun, earth, and moon form a right angle and the gravitational pull of the sun counteracts the pull of the moon.

fjord

A drowned glaciated valley, or glacial trough, along a seacoast.

earthquake

A sharp release of energy that sends waves traveling through Earth's crust at the moment of rupture along a fault or in association with volcanic activity. The moment magnitude scale (formerly Richter scale) estimates earthquake magnitude; intensity is described by the Mercalli scale.

geomorphic threshold

A tipping point where the system lurches to a new operational level. o This threshold is reached when a geomorphic system moves from the slow accumulation of small adjustments to a point of abrupt change that takes it to a new system state. 1. The threshold up to which landforms change before lurching to a new set of relationships, with rapid realignments of landscape materials and slopes.

subduction zone

An area where two plates of crust collide and the denser oceanic crust dives beneath the less dense continental plate, forming deep oceanic trenches and seismically active regions. •When continental crust and oceanic crust slowly collide, denser ocean floor will grind beneath the lighter crust forming subduction zone (@ convergent plate boundaries)

hot spots

An individual point of upwelling material originating in the asthenosphere, or deeper in the mantle; tends to remain fixed relative to migrating plates; some 100 identified worldwide, exemplified Yellowstone National Park, Hawaii, and Iceland. •sites of upwelling material/magma; formed under oceanic and continental crust and are fixed relative migrating plates • found beneath oceanic/continental crust and are fixed relative migrating plates • e.g. Hawaii-Emperor (80 mya) with oldest furthest NW corner; Iceland

denudation

Any process that wears away or rearranges landforms A general term that refers to all processes that cause degradation of the landscape: weathering, mass movement, erosion, and transport.

Overview of Earth's Deserts Desert Climates Desert Fluvial Processes

Arid Regions • distribution f(x) 3 factors: sub-tropical HP (15-35o); rain shadow (leeside); distance from moisture bearing air-masses (central Asia) • interaction btw limited precipitation, weathering and wind • climatically: high sensible heat and ground heating, high insolation (clear skies), high radiative heat loss; high POTET, low precipitation, large water deficits • fluvially: intermittent flow; high runoff and flash-floods • dry desert channels: 1-2 years/rainfall event; wash, arroyo, wadi • evaporation in desert environments leaves evaporative salts

First, second, third Order of Relief

Crustal Orders of Relief • 3 orders (classified by scale) - 1st order: huge continental platforms/ocean basins - 2nd order: mountain masses, plains, lowlands - 3rd order: ind. mountains, valleys, cliffs

Landmass Denudation

Denudation - wears away/modifies landforms • Weathering • Water

convergent, divergent, transform boundaries

Earth's Major Plates: 1. collision zones (continental vs. oceanic); compression and crustal loss, e.g. Andes; Himalaya •collision zones (continental vs. oceanic); compression and crustal loss ◦Andres, Himalaya 2. mostly oceanic - sea-floor spreading centers (spreading/tension) e.g. Nazca Plate; continental e.g. Great Rift Valley •mostly oceanic, sea-floor spreading centers (spreading/tension) ◦Nazca Plates; continental. Great Rift Valley 3. slide laterally past one another, e.g. sea-floor spreading centers;transform faults - parallel to plate movement, e.g. San Andreas Fault • slide laterally past one another at right angle to sea-floor spreading centers

Earth's Structure and Internal Energy

Earth's Structure: Formed 4.6 bya Structure: Core-->Mantle-->Lithosphere and Crust o Earth is thought to have condensed from a nebula of dust, gas, and icy comets about 4.6 billion years ago. o Earth solidified and gravity sorted materials by their densities. lighter elements to surface (SiO2) o Earth's interior consists of roughly concentric layers each distinct in either composition or temperature

horst and graben

Horst: upward-faulted blocks Graben: downward faulted blocks

endogenic vs. exogenic

Internal. 1.The system internal to Earth, driven by radioactive heat derived from sources within the planet. In response, the surface fractures, mountain building occurs, and earthquakes and volcanoes are activated. External. 2. Earth's external system, powered by insolation, which energizes air, water, and ice and sets them in motion, under the influence of gravity. Includes all processes of landmass denudation.

ablation

Loss of glacial ice through melting, sublimation, wind removal by deflation, or the calving of blocks of ice.

abrasion

Mechanical wearing and erosion of bedrock accomplished by the rolling and grinding of particles and rocks carried in a stream, removed by the wind in a "sandblasting" action, or imbedded in glacial ice.

exotic stream

Q decreases with distance (high POTET rates arid environments) - e.g. Nile River, Colorado 1. a stream (such as the Nile) that has its source in well-watered lands and crosses a desert on its way to the sea

Earthquakes

Stress (force) builds strain (deformation)-->friction overcome and plates slide past one another (plate boundary)-->release of seismic energy

The Grand Tetons and the Sierra Nevada

The Grand Tetons and the Sierra Nevada o Examples of recent stage mountain building (landscapes can be altered when a normal fault along one side of a range produces a tilted linear landscape with a dramatic relief known as a tilted-fault block mountain range. o Caused by magma intrusions that cooled to form granitic cores of coarsely crystalline rock o Sierra Nevada- some of the uplift in the range was isostatic in response to the erosion of melting ice

geothermal energy

The energy in steam and hot water heated by subsurface magma near groundwater. Geothermal energy literally refers to heat from Earth's interior, whereas geothermal power relates to specific applied strategies of geothermal electric or geothermal direct applications. This energy is used in Iceland, New Zealand, Italy, and northern California, among other locations.

geomorphology

The science that analyzes and describes the origin, evolution, form, classification, and spatial distribution of landforms

geologic time scale, Holocene, Pleistocene

Timeline of Earth's History 1. • The full scope of Earth's history •Breaks the past 4.6 billion years down into eons (the largest time span) then into shorter time spans of eras, periods, and epochs. •Major events in Earth's history determine the boundaries between these intervals (they're not equal in length) •Geologists assign ages to events or specific rocks, structures, or landscapes using this time scale based on relative time or absolute time --- Absolute vs. Relative Timescale ----Relative: sequence of events in order they occurred >Superposition---arrangement of strata >Stratigraphy---study of sediment sequences ----Absolute: Uses of radioactive decay of isotopes 2. Holocene: Present- 10 kya most recent epoch in the geologic time scale consisting of the 11,500 years since the last glacial period As the impacts of humans on Earth systems increase, numerous scientists believe we are in a new epoch called the Anthropocene 3. Pleistocene: 10k- 1.8 mya •Earth's most recent period of repeated glaciations, began 2.5 million years ago.

Weathering Processes

Weathering: process that breaks down rock at Earth's surface and slightly below, either disintegrating rocks into mineral particles or dissolving it into water o Weathering weakens surface rock, making it more susceptible to the pull of gravity · Physical vs. Chemical o Physical (mechanical): § The disintegration of rock without any chemical alternation § By breaking up rock, physical weathering produces more surface area on which all weathering may operate § Examples: ú Frost Action - Repeated freezing (expanding) and thawing (contracting) of water is this, which breaks rocks apart in the process of frost wedging ú Talus - I couldn't find this in the book?? ú Salt-Crystal Growth - As crystals accumulate and grow, they exert a force great enough to separate the grains making up the rock and begin breaking the rock to pieces, a process known as SCG ú Exfoliation - The process whereby rock peels or slips off in sheets instead of breaking up into grains (can be arch shaped or dome shaped) · Exfoliation domes are probably the largest weathering features, in areal extent on Earth · Thought to occur as pressure is released from the removal of overlying rock o Chemical: § Refers to the chemical breakdown, always in the presence of water, of the constituent minerals in rock ú Chemical decomposition and decay become more intense as both temperature and precipitation increase § Examples: ú Spheroidal weathering - chemical weathering that softens and rounds the sharp edges and corners of joined rock as water penetrates the joints and dissolves weaker minerals or cementing materials ú Hydration - meaning "combination with water," involves little chemical change but does involve a change in structure · Water becomes part of the chemical composition of the mineral, forming a hydrate (absorption of water) (ex. Gypsum) ú Hydrolysis - decomposition of a chemical compound by reaction with water · In geomorphology, hydrolysis is of interest as a process that breaks down silicate minerals in rocks · In contrast with hydration, hydrolysis chemically breaks down a minerals, thereby producing a different mineral through the chemical reaction ú Oxidation - When certain metallic elements combine with oxygen to form oxides. · Ex. Most familiar- rusting of iron ú Carbonation - Breaks down minerals that contain calcium, magnesium, potassium, or sodium · (Water is called the universal solvent because it is capable of dissolving at least 57 of the natural elements and their compounds)

salinity

[dissolved solids] by volume = 35‰ ! concentration varies f(x) of fH20 flows and atmospheric conditions • sub-tropical (36%o) vs. equatorial (34.5 ‰) • brine: > 35‰; brackish <35‰ • e.g. Red Sea 225‰; Gulf of Bothnia 10‰; Sargasso Sea 38‰ Chemical Composition of Seawater - Water 'universal solvent'-->seawater is a solution - Ocean chemistry: f(x) of interchange btw seawater, atmosphere, minerals, bottom sediments and biota - 99% of dissolved solids comprised of 7 elements (Cl, Na, Mg, SO4, Ca, K, Br) 1. The concentration of natural elements and compounds dissolved in solution, as solutes; measured by weight in parts per thousand (%o) in seawater

seismograph

an instrument used to detect or record the ground motion that occurs during an earthquake 1. Instrument used to detect and record the ground motion during an earthquake caused by seismic waves traveling through Earth's interior to the surface.

slopes

are curved, inclined surfaces that form the boundaries of landforms 1. A curved, inclined surface that bounds a landform.

alluvium

clay, silt and sand deposited by stream 1. General descriptive term for clay, silt, sand, gravel, or other unconsolidated rock and mineral fragments transported by running water and deposited as sorted or semisorted sediment on a floodplain, delta, or streamed.

Biological Processes: Coral Formations

coastlines form from coral growth • coral: marine animal (polyp)-->CaCO3 (hard shell - protection) • symbiotic with algae-->coral cannot p/s but can ingest nutrients; algae p/s provide nourishment for coral • environmental conditions: 30oN/S, max depth 55m, salinity 27-40 0/00, temperature 18-29oC, clear sediment free water • temperature important-->more common along east coasts • coral reefs: formed by constantly expanding live corals at ocean • surface (built upon fossil corals); biologically derived sedimentary rock • volcanic islands and corals: fringing, barrier, atolls • e.g. Great Barrier Reef, Queensland, Australia (~2000 X ~30 km) • coral bleaching: color ! white (death of red-brown to green - no nutrient supply); warming of SSTs (1-2oC)

drainage density, pattern

continental divides: regional drainage basins (highlands/mountains)-->direct flow Pacific, G. of Mexico, Atlantic, Hudson Bay, Arctic • e.g. Ohio, Mississippi and Missouri drainage complex • open systems: inputs (ppt. and sediment) and outputs (water, sediment) • constantly responding/adjusting to changes in landscape (load vs. discharge and velocity) • internal drainage-->areas of interior drainage (Great Basin) 1. drainage density: total length/area • f(x): topography and climate • drainage pattern ! arrangement of channels (structure and relief) • f(x)-->steepness, rock resistance, climate, hydrology, relief and geology 2. A distinctive geometric arrangement of streams in a region determined by slope, differing rock resistance to weathering and erosion, climatic and hydrologic variability, and structural controls of the landscape. patterns: dendritic (dendron Greek - 'tree') trellis - dipping/folding topography (Ridge and Valley province) + stream capture; radial - central peak/dome parallel - steep slopes rectangular - faulted/jointed landscapes

drumlin

deposited till shaped in direction of ice movement (blunt upstream; tapered end downstream), NY, WI, ON A depositional landform related to glaciation that is composed of till (unstratified, unsorted) and is streamlined in the direction of continental ice movement--blunt end upstream and tapered end downstream with a rounded summit.

topography

describes Earth's surficial form

Hypsometry

distribution of Earth's surface and elevation in relation to sealevel

Drainage Basins

drainage basin-->drainage divides-->watershed (water receiving area of the drainage basin)

elastic-rebound theory

fault zone locked due to friction 1. A concept describing the faulting process in Earth's crust, in which the two sides of a fault appear locked despite the motion of adjoining pieces of crust, but with accumulating strain, they rupture suddenly, snapping to new positions relative to each other, generating an earthquake.

joints

fractures or separations in rock that occur without displacement of the rock on either side (in contrast with faulting) 1. A fracture or separation in rock that occurs without displacement of the sides; increases the surface area of rock and exposed to weathering processes.

crevasses

friction with valley walls, stretching (convex), compression (concave) A vertical crack that develops in a glacier as a result of friction between valley walls, or tension forces of extension on convex slopes, or compression forces on concave slopes.

tsunami

harbor wave): formed by deep-sea movements-->long wave length, shallow waves, travel quickly (500-800 kmph)-->wave height dramatically increases reaching shore (shortening wave length) 1. A seismic sea waves, traveling at high speeds across the ocean, formed by sudden motion in the seafloor, such as a seafloor earthquake, submarine land-slide, or eruption of an undersea volcano.

wave-cut platform

horizontal bench extending out from sea cliffs 1. A flat or gently sloping, table-like bedrock surface that develops in the tidal zone where wave action cuts a bench that extends from the cliff base out into the sea. ---horizontal bench extending out from sea cliffs

continental glacier

larger in extent (largest form: ice sheet); Greenland, Antarctica • weight-->isostatic depression submerging land below sea-level (3,000 m thick) • ice caps - circular, < 50,000 sq km, buries underlying landscape • ice field - not as extensive, elongated shape (linear), e.g. Patagonia • nunatak - raised mountain tops

snowline

lowest elevation where snow can exist year-round (summer)-->elevation varies with latitude (tropical: 5000m, mid-latitude 2700m, high latitude 600m) A temporary line marking the elevation where winter snowfall persists throughout the summer;

lava

magma that has cooled to form rock

terranes

migrating piece of Earth's crust-->mantle convection and plate tectonics (distinct in history, composition and structure) •migrating piece of Earth's crust which have become attached to the plates ◦displaced terranes have history from other continents and differ in rock composition 1. A migrating piece of Earth's crust, dragged about by processes of mantle convection and plate tectonics. Displaced terranes are distinct in their history, composition, and structure from the continents that accept them.

alluvial fan

mouth of canyon-->flowing water loses velocity (transport capacity) 1. Fan-shaped fluvial landform at the mouth of a canyon; generally occurs in arid landscapes where streams are intermittent.

The Appalachian Mountains

o Plate movement created active plate boundaries and several orogenic periods that gave rise to the mountains we know today (Atlas Mountains of Mauritania and northwestern Africa were once connected)

mean sea level (MSL)

ocean currents, air pressure, wind patterns, water density/temperature 1. The average of tidal levels recorded hourly at a given site over a long period, which must be at least a full lunar tidal cycle.

discharge

potential energy (gravity)-->kinetic energy: f(x) of steepness of stream channel • stream channel: width vs depth and velocity vs sediment load • discharge - stream's flow rate (velocity x width x depth; Q = wdv) • Increase Q-->increase in w, d or v (m3/s; cfs) • Increase Q: scouring and transport material • increased Q downstream due to larger area being drained discharge - stream's flow rate (velocity x width x depth; Q = wdv) 1. The measured volume of flow in a river that passes by a given cross section of a stream in a given unit of time; expressed in cubic meters per second or cubic feet per second.

Periglacial Landscapes

processes, landforms, topography associated with glacially adjacent areas (past/present)-->20% Earth's surface • near-permanent ice and seasonally snow-free-->permafrost, frost action, ground ice • Geography of Permafrost • Ground Ice and Frozen Ground Phenomena • Humans and Periglacial Landscapes

glacier surge

rapid movement of glacier downslope; causes not understood-->water may be causal agent, floats glacial ice The rapid, lurching, unexpected forward movement of a glacier.

blowout depressions

removal of loose sediment-->shallow basins (chemical weathering removes cementing materials - e.g. Qattâra Depression) 1.

permafrost, active layer

requires 2 years of sub-zero temperature (soil/rock) 1. Forms when soil or rock temperatures remain below 0 degrees C (32 degrees F) for a least 2 years in areas and considered periglacial; criterion is based on temperature and not on whether water is present. 2. A zone of seasonally frozen ground that exists between the subsurface permafrost layer and the ground surface. The active layer is subject to consistent daily and seasonal freeze-thaw cycles.

Physical Structure of the Ocean Inputs to the Coastal System

surface: mixing zone (2% of volume); well-mixed • thermocline: transition zone, 1 km thick with steep temperature gradient, little mixing (18%) • cold zone: uniform salinity/temperature values, ~0oC (doesn't freeze due to salinity and pressure), at surface H20 freezes at ~ -2oCCoastal System • coastlines-->dynamic equilibrium btw wave energy, tides, wind, currents, sediment supply, slope of coastal plain, sea-level fluctuations • inputs: - solar energy (hydrosphere and atmosphere) ! climate and weather - winds-->ocean currents and waves - climate regimes-->coastal geomorphology (ppt) - coastal geology-->erosion/sediment production - human activities

relief

vertical elevation differences in the landscape

Mass Movement Processes

· Mass Movement: (Mass Wasting) Is the downslope movement of a body of material made up of soil, sediment, or rock propelled by the force of gravity. o Rate of movement dependent on precipitation and temperature · Angle of Repose: The steepness of the resulting slope; depends on the size and texture of the grains o Represents a balance of the driving force (gravity) and the resisting force (friction and shear) · Rockfall: A volume of rock that falls through the air and hits a surface o Individual pieces fall independently and characteristically form piles of irregular broken rock called talus. Landslide, debris avalanche, mudflows, etc.

Plate Tectonics

• A Brief History • symmetry among continents (SA and Africa) noted early • Wegener (1912) - continental drift - migrating landmasses • Pangaea (super continent) ~ 225 million BP (Triassic); mid-latitude coal deposits (Permian/Carboniferous Periods) due to once being near equator • Tectonic - "building/construction" - changes in Earth's crust (internal forces) • Plate tectonics - upwelling of magma, crustal plate movements, sea-floor spreading and subduction, earthquakes, volcanic activity, warping/folding/faulting of crust The conceptual model and theory that encompass continental drift, seafloor spreading, and related apsects of crustal movement; accepted as the foundation of crustal tectonic processes.

dynamic equilibrium model

• Balance (tectonic uplift vs. weathering/erosion) • Relief vs. energy (potential, mechanical, chemical) • Geomorphic threshold • Steps: • 1) equilibrium stability • 2) destabilizing event • 3) adjustment period • 4) new stability level 1. The balancing act between tectonic uplift and erosion, between the resistance of crust materials and the work of denudation processes. Landscapes evidence ongoing adaptation to rock structure, climate, local relief, and elevation.

Earth's Surface Relief

• Crustal Orders of Relief • 3 orders (classified by scale) - 1st order: huge continental platforms/ocean basins •Coarsest level of landforms, including ◦continental landmasses - portions of crust that reside above or near sea level, including undersea continental shelves among coastlines ◦ocean basins - entirely below sea level - 2nd order: mountain masses, plains, lowlands •intermediate level. ◦continental features - mountain masses, plains, and lowlands ◦ocean - continental rises, slopes, abyssal plains, mid-ocean ridges, submarines canyons, and oceanic trenches - 3rd order: ind. mountains, valleys, cliffs •most detailed ◦continental - individual mountains, cliffs, valleys, hills, and other smaller forms • Hypsometry - distribution of Earth's surface and elevation in relation to sealevel • Earth's Topographic Regions • Plains • High tablelands • Hills and low tablelands • Mountains • Widely spaced mountains • Depressions

Glacial Processes

• Formation of Glacial Ice - mass of ice-->snow/water: compaction, re-crystallization and growth-->flows downslope - glacial ice formation: frozen fluid (igneous)! accumulation of ice ~ to sedimentary layers-->pressure transforms snow (metamorphic) - input: accumulation of snow in accumulation zone--> highest elevation • weight (pressure) increases with increased depth-->snow surviving summer melt-->glacial ice • air spaces squeezed out (pressure)-->firn (granular texture) over time firn re-crystallized into glacial ice • Glacial Mass Balance • Glacial Movement

glacier

• Majority of frozen water: Greenland and Antarctica • melting at an unprecedented pace • ~20% of world-->freezing conditions/ frost action • glacier: mass of ice-->on land or floating (ice shelf) adjacent to land • form-->continual accumulation of snow-->re-crystallizes into ice (weight) • not stationary-->flow (fluid); gravity and weight • 11% of Earth's surface glacial (30% in past) A large mass of perennial ice resting on land or floating shelflike in the sea adjacent to the land; formed from the accumulation and recrystallization of snow, which then flows slowly under the pressure of its own weight and the pull of gravity.

Coastal System Actions

• Tides: daily cycle in sea-level ! geomorphic agent (sediment erosion/transportation + Navigation, fishing, recreation) • Causes: gravitational pull of Sun and Moon - pull of Moon tugs on Earth's atmosphere, oceans and lithosphere-->creates tidal bulges in all 3 spheres (effectively only ocean is of interest) - gravity: force of attraction btw two bodies (with mass) - inertia: bodies resist change • Waves

Crustal Deformation Processes

• all rock subjected to stress (FORCE): - tension (stretching) - compression (shortening) - shear (twisting/tearing) Rocks respond to stress by: 1. Folding and Broad Warping: When convergent plate boundaries intensely compress rocks and deform them The bending and deformation of beds of rock strata subjected to compressional forces. 2. Faulting: Rocks on either side of the fracture (caused by stress) displace relative to the other side The process whereby displacement and fracturing occur between two portions of Earth's crust; usually associated with Earthquake activity. • Convergent plate boundaries - compression-->folding • anticline - ridge of a fold, slope downward away from axis • syncline - trough of fold, slope downward toward the axis; • thrust fault - overturned folds • warping - greater in extent; e.g. isostatic rebound (Canada)

alpine glacier, cirque

• alpine glacier (from Alps): mountains; • valley glacier: constrained in a stream-formed valley (river of ice) • movement of these valley glaciers heavily modify landscape (erosion and transportation) • originate in snowfield in scooped out bowl ! cirque (cirque glacier) join together in valley 1. A glacier confined in a mountain valley or walled basin, consisting of 3 subtypes: valley glacier(within a valley), piedmont glacier(coalesced at the base of a mountain, spreading freely over nearby lowlands), and outlet glacier(flowing outward from a continental glacier). 2. A scooped-out, amphitheater-shaped basin at the head of an alpine glacier valley; an erosional landform.

base level

• base level (Powell; USGS): the level below which a stream cannot erode its valley • imaginary surface extending inland from sea-level (lowest level of denudation processes) • local base-level: river, lake, resistant strata (lower limit of local streams) 1. A hypothetical level below which a stream cannot erode its valley-- and thus the lowest operative level for denudation processes; in an absolute sense, it is represented by sea level, extending under the landscape.

The Geologic and Rock Cycle

• deals with Earth's crust • endogenic (internal) • exogenic (external) • internal heat, solar energy (gravity) • 3 subsystems • hydrologic cycle • erosion, transportation, deposition • rock cycle • 3 basic rock types • tectonic cycle • moves material btw surface and mantle

Stream Erosion and Transportation

• erosion: turbulence and abrasion-->modify landscape • hydraulic action-->work done by flowing water alone (squeeze-release action: loosens and lifts rocks)-->further erosion of streambed: (mechanically) abrasion • upstream: hydraulic influence vs. downstream: sediment load 1.

meandering stream

• highest v-->deepest part of channel • three types channels: braided, straight and meandering • meandering - sinuous pattern develops when slope is gradual • undercut bank - outer portion of each meander (high v, scouring action) • point bar - low v-->sediment deposited; migrate downstream (landscape) 1. The sinuous, curving pattern common to graded streams, with the energetic outer portion of each curve subjected to the greatest erosive action and the lower-energy inner portion receiving sediment deposits.

internal drainage

• internal drainage-->areas of interior drainage (Great Basin) 1. The downward movement of water through the soil profile. The rate of movement is determined by the texture, structure, and other characteristics of the soil profile and underlying layers and by the height of the water table, either permanent or perched. Relative terms for expressing internal drainage are none, very slow, medium, rapid, and very rapid.

karst topography, formation

• limestone dominated areas with poor surface drainage • 15% Earth's surface • surface topography: pitted, bumpy with surface channels and caverns • Krs Plateau (Solvenia); China, NM, KY • Formation of Karst: 80% CaCO3; complex jointing pattern, aeration, vegetation, precipitation • landscapes/features: • sinkholes and caverns • karst valley: elongated depression • tower karst: differential weathering • dripstones: stalactites vs. stalagmites 1. Distinctive topography formed in a region of chemically weathered limestone with poorly developed surface drainage and solution features that appear pitted and bumpy; originally named after the Krs Plateau in Slovenia. 2. o For limestone landscape to develop into karst, these conditions are necessary: § The limestone formation must contain 80% or more calcium carbonate for dissolution processes to proceed effectively § Complex patterns of joints in the otherwise impermeable limestone are needed for water to form routes to subsurface drainage channels § An aerated (air-containing) zone must exist between the ground surface and the water table § Vegetation cover is needed to supply varying amounts of organic acids that enhance the dissolution process

Erosional Landforms Created by Alpine Glaciation

• pre-glacial: stream-cut, v-shaped valleys Figure 17.10 • glacial period: regolith/soils removed by erosion/transportation; cirques walls eroded--> arêtes (saw-toothed: Sierra) ! col (depression/pass)-->horn (pyramid eroded on 3 sides) • post-glacial period: glaciated valleys (U-Shaped), steep slopes and debris fall (talus); tarn: former cirque depression filled by lake; paternoster lakes: stair-case lakes/chain; hanging valleys (waterfalls); fjord: glacial trough reaching sea-->glacial retreat and sea level rise floods valley (Alaska, Norway, Chile)

Crustal Formation Processes

•Continental Shields: region where craton is exposed at the surface ◦craton = nucleus of continent/landmass • Terrane: migrating piece of Earth's crust which have become attached to the plates ◦displaced terranes have history from other continents and differ in rock composition • continental shields • building continental crust and terranes f(x) of tectonic activity and weathering and erosion • Continental Shields (exposed craton) - nucleus: ancient crystalline rock (craton - heartland); eroded to low relief and elevation