Download Water and Groundwater: Properties, Zones, and Uses and more Quizzes Physical Geography in PDF only on Docsity!
Where is water?
Glaciers - 77% Groundwater - 22% Surface water - 0.3% Soil moisture - 0.1% Atmosphere - 0.04% Saline water - 97% Fresh water - 3% TERM 2
Groundwater &
Flow
DEFINITION 2 Groundwater : Water under the Earth's surface, within sediments or cracks in rock; largest accessible source of fresh waterRecharge area: place where surface water infiltrates aquiferDischarge area: place where groundwater flows back up to surface Porosity : percent pore space in sediment or rock (how much?) Permeability : capability of a substance to allow the passage of water (how is pore space connected?) TERM 3
Examples of Porous Rocks
DEFINITION 3 High porosity materials Sand, sandstone, conglomerate, limestone Pumice & scoria Low porosity materials Clay/ shale Most igneous and metamorphic rocks High porosity doesn't mean high permeability (e.g. pumice) TERM 4
Water Table &
Saturation
DEFINITION 4 Water Table : boundary between saturated and unsaturated zones; mimics topography; when the water table intersects the land surface, a body of water will form Unsaturated zone: air and water in pores Saturated zone: water only in pores TERM 5
Aquifers &
aquicludes
DEFINITION 5 Aquifer : layer of rock/sediment with permeability high enough to produce usable amounts of water Sand, sandstone, conglomerate, limestone Aquiclude (aquitard) : layer of rock/sediment that doesn't conduct water in usable amounts Clay, shale, crystalline bedrock Potentiometric surface : elevation that water within a confined aquifer will rise to due to confining pressure
A: Regional water table B: Perched water table C: Unconfined aquifer D: Continuousimpermeablelayer E: Confined aquifer (under pressure) TERM 7
Artesian wells
DEFINITION 7 Artesian well: A well that taps into the water table? Flowing artesian well : Water flows from well without pumping TERM 8
Groundwater issues
DEFINITION 8 Over-consumption:causes the water to lowerSubsidence: Lowering of the land surface (why the leaning tower of Pisa leans!)Saline intrusionFlow reversal TERM 9
Drainage basin area
DEFINITION 9 Area enclosed by the drainage divides TERM 10
Stream flow
DEFINITION 10 Stream flow : how much water is flowing in a streamMeasured as discharge (Q) = volume per timeMeasured with stream-gauging station
Surface Water Use Issues
Pollution (Cuyahoga River)Damming (Hoover dam)Overuse (Aral Sea) TERM 17
Karst landscapes
DEFINITION 17 Weathering due to chemical dissolution of limestoneRequires limestone bedrock and abundant groundwaterOften forms caves: dissolution of limestone by groundwater TERM 18
Speleothems
DEFINITION 18 Stalactites (down)Stalagmites (up) TERM 19
Karst landscape
features
DEFINITION 19 Sinkholes : circular depression due to cavern collapse Natural bridgesDisappearing stream : surface streams that flow into cave system TERM 20
Drainage networks
DEFINITION 20 Dendritic - tree like Radial - from a volcano Rectangular - along joints Trellis - between mountain ranges
Coastline
Shapes
Shapes vary because Sea level fluctuations Waves TERM 22
Emergent coastlines
DEFINITION 22 Occurs when the: Sea level falls Tectonic uplift Creates: Steep cliffs Terraces Wave notches TERM 23
Submergent coastlines
DEFINITION 23 Occurs when the: Sea level rises Tectonic sinking Creates: Estuaries : mixing of saline and freshwater systems Flooded river valleys(How the Chesapeake Bay formed) Barrier islands (inlets, salt marsh, lagoons/ bays) TERM 24
Barrier islands
DEFINITION 24 Inlets serve to allow sand movement from island to islandSalt marches and lagoons form protective environmentsMigrate toward the mainland with sea level rise TERM 25
Wave orbitals
DEFINITION 25 Waves are formed by wind on the waterWave energy moves, not the water so floating things stay in place(like garbage island!)Wave base is where particle motion ends
Ocean water
Ocean water is mostly composed of chloride and sodiumSalt ions come from: Chemical weathering Transport of dissolved load in rivers Volcanic gases (like at MORs) TERM 32
Oceans: Salinity
DEFINITION 32 Salinity: the saltiness or dissolved salt content of a body of water. Greatest in the tropics, lowest at highest altitude More chemical weathering occurs in warmer climates Variable salinity in surface oceans, but equals off in the Halocline TERM 33
Oceans: Temperatures
DEFINITION 33 Thermocline is where there is the most rapid transitions in temperature TERM 34
Oceans: Surface currents
DEFINITION 34 Surface currents : Driven by wind at the surface ( upper 400 m) Gyre : the circular portion at the center of ocean currents (e.g. Garbage Island, the book Moby Duck) Upwelling : Deflection of water away from the coastline and deeper, colder waters rise near shoreline (causing increased biodiversity)Surface currents can also heat and cool overlying air! TERM 35
Oceans: Deep water currents
DEFINITION 35 Deep water currents : Driven by differences in temperature and salinity (density) Coriolis effect : Current direction offset by rotation of Earth (~45d);Greatest deflection at the surface, decreases with depth Thermohaline circulation
Oceans: El Nio & La
Nia
El Nio causes warmer temperatures and greater wind speeds that are opposite of normal air flow Causes northern hemisphere; wet winter in gulf; drier inOceania; warmer in Canada La Nia causes cooler temperatures and variable wind speeds that exaggerate upwelling Causes drier & warmer in weather in the Gulf; wet inOceania; cool and wet in Canada TERM 37
Ocean-climate connection
DEFINITION 37 Oceans store heat Water has higher heat capacity than air Upper 10 ft of ocean holds as much heats atmosphere Oceans redistribute heat Horizontally by surface currents from tropics to poles, vertically by deep currents Changes in this redistribution can lead to ice ages Oceans store CO About 50% total CO2 added to atmosphere by humans in the last century absorbed by oceans Acidifies oceans TERM 38
Younger-Dryas cooling
DEFINITION 38 11.5 - 12.8 thousand years agoCaused by shut down of thermohaline circulation in North AtlanticMelt water of retreating glaciers adds fresh water to North AtlanticNo heat transfer, no down-welling TERM 39
Glaciers
DEFINITION 39 Ice mass that originates on land Result of the accumulation, compaction, andre-crystallizationof snow Erosion by glaciers removes material, leading to characteristic landforms On land : glacier Partially over water : ice shelf Water only : sea ice TERM 40
Glacial stratigraphy
DEFINITION 40 Glaciers are made up of: Loose snow (90% air) Granular snow (50% air) Firm snow (25% air) Fine grained ice (<20% air, in bubbles) Coarse grained ice (<20% air, in bubbles)
Glacial
features
Braided river : occur because there is so much sediment Kettle lake : result of chunks of ice Drumlin : small, tear-dropped shaped hills that show the direction of original ice flow Esker : develop as melt water channels are chocked with sediment Erratics :Large, out-of-place boulders moved by glaciers TERM 47
Glacier-climate connection
DEFINITION 47 Glaciers store water Local : regulate community water supplies Global : affect sea level Glaciers reflect solar radiationGlaciers are key in understanding climate change Provides information on atmospheric composition Records vegetation changes (pollen) Serves as a proxy for temperature changes TERM 48
Glacier ice budget
DEFINITION 48 Glaciers represent a balance between: Accumulation - addition of ice (precipitation) Ablation - loss of ice (melting, calving, sublimation) TERM 49
Glacial dynamics
DEFINITION 49 Glacial advance = more accumulationGlacial retreat = more ablutionThe ice in a glacier is always moving away from the zone of accumulationRetreat and advance always refer to the relative position of the toe of the glacier
