GY 102 Final Exam Pitts

Cape Cod

"curled first" is mostly a spit, other features are sand bars and barrier islands

International Drainage Basin

-1770 miles -9 countries -most polluted river on earth -transport, municipal, supply, irrigation, fishing, HEP, industrial, mining, sewage, chemical

Physical structure of Oceans and Seas

-3 layers -mixing zone 2% -Thermocline transition 18% -Deep cold 80%

What happens when the water table begins to over pump?

-A larger well causes cone of depression in the water table which changes the direction of flow -A cone of depression forms because the water cannot flow fast enough to replenish the amount of water that is withdrawn from the well -In many cones, the water table become steeper near the well because the water is withdrawn too fast

The Delaware River Basin

-Atlantic drainage basin -47 in precipitation -13,000 miles, 370 miles long -5 states, humid temperate climate -supplies 20 million people with water -Delaware Aqueduct, Delaware Canal -Reservoirs to control streamflow and storage

How do streams interact with water table?

-River lower than water table can gain water from inflow of groundwater -River higher than water table can lose water to groundwater -Mound of groundwater can form below river due to outflow of river water into groundwater

What determines whether a shoreline gains or loses sand with time

-Sediment derived from erosion on land is carried to the ocean if there is sufficient precipitation -Rivers provide an influx of sediment -Deltas act as the river-sea interface and can contribute sediment that is transported offshore or along the coast -Coastal dunes consist of sand blown onto land from the beach (a net loss of sand from the beach) -The longshore current transports sediment parallel to the coast and can add additional sand to the beach (a net gain of sand) -Waves erode reefs and offshore islands, carrying loose sediment toward the coast, increasing the amount of sand on the beach Sediment generated by wave erosion adds to the sand budget

What do you think are the consequences of a dam?

-a dam represents a new temporary base level for a river -river deposits sediment as in a distributary system -delta builds out into the reservoir and fills up basin with sediment -clear and cold water released from dam unlike pre-dam flows -sediment poor water erodes areas downstream -dams built for flood control, power generation, water storage, recreation and other uses

Glacier

-a large mass of ice resting on land or floating in the sea -accumulation of snow-recrystaliizes into ice mass

Porosity

-amount of open pore space -how much it can store -expressed as a percent -10-30% high porosity -dependent on size, shape, orientation and degree of compaction of mineral grains

Coral Reefs

-colonial, build on dead skeletons -reef is biologically derived sedimentary rock -fringing, barrier, atoll

How does groundwater contamination move?

-contamination largely moves with groundwater down the slope of the water table -can be naturally filtered out with enough time, flows slowly and in contact with material like sand -not filtered if flows rapidly through a rock, such as limestone with open cavities

Salinity

-dissolved solids by volume, concentration -expressed as a 3.5% or 35% per thousand -parts per million 35000=35000 mg/liter -varies 3.4-3.7% -Due to precipitation and evaporation

Example of Coastal Hazards

-erosion -overwaash -inundation

How do meanders form and move?

-faster side erodes and deepens -deep side carries more and faster water so we get more erosion forming a cutbank -inside has less water and moves slower so it deposits forming a point bar -Meander erodes its outside bend increasing curvature and the meander migrates outward and downstream -continued erosion or overflow during a flood can cut off meander and form an oxbow lake

How is material transported and deposited?

-fine particles can be carried in suspension floating in water -sand grains can roll and bounce along (saltation) -cobbles and boulders mostly roll and slide during high flows -material moving on river bed load -soluble ions are dissolved and carried by moving water

Graphing floods and non-flood flow

-flood stage generally shows the level where water overfills the channel and spills out onto the floodplain

What are other environmental consequences?

-flooding sites -losing more water to evaporation -river no longer carries sediment downstream to replenish nutrients on floodplain -silting shortens life of reservoir

Glacial Transport

-glaciers transport material at the surface, interior and base

Permeability

-measure of interconnectedness of pores -how well it transmits -primary-intragranular -secondary-fracture systems, solution networks

How can water become contaminated?

-mining and natural mineralized rock -landfill -farm -septic tank -leaking tank in gas station -truck fuel spill -fuel storage tanks -factory wells, spills and emissions -dry cleaners -households -brought from outside area by groundwater -brought by river

Characteristics of a glacier

-moving mass of ice with rocks and finer sediment -cover broad areas or confined to valleys -flow from higher to lower elevations -glaciers can merge becoming a wider, thicker glacier -formation depends on snowfall, temperature, direction and steepness of slopes, etc.

Wetlands

-saturated with water enough of the time to support hydrophytic vegetation -poorly drained soils -coastlines, bogs, cypress swamps, river bottoms, and flood plains, permafrost arctic and sub arctic areas

Shoreline features carved by erosion

-sea cliffs -caves and sea arches -Pinnacles and sea stacks -wave cut platform

Causes of Floods

-snowmelt -local precipitation -regional precipitation -ice dam -volcanic eruption -dam failure

How does a spit

-spit forms when waves and longshore currents transport sediment along beach

How a glacier forms and changes as it moves downhill

-the upper part of the glacier is where snow can accumulate faster than it melts -the glacier moves downhill, the loss of ice and snow to melting is in exact balance with the amount of accumulation -At lower elevation, ice melts faster than is is replenished causing glaciers to terminate -the amount of trapped air in the ice and selective light absorption help explain for the white vs blue color

Chemical structure of oceans and seas

-universal solvent -solutes-dissolved solids -seawater is a solution -concentration of dissolved soilds=salinity -Uniform globally -3.5%

Factors the affect the appearance of a shoreline

-waterside vs. land side -wave erosion occurs during storms -steep shorelines allow waves to break close to shore -orientation of a shoreline relative to prevailing direction of waves -availability and type of sediment like from rivers -climate controls, precipitation amount, vegetation type and intensity of rainfall -whether coastline has been exposed by falling water level, flooded by rising ones or is relatively stable

Process that affect shorelines

-waves are generated from the wind, move sediment, and erode and deposit material -rivers deliver sediment to the shorelines, coarser deposited close to the shoreline, fine carried farther -wind moves sand and finer sediment, coastal dunes -tectonic activity can uplift or down drop coast -changes in sea level from kids and other factors -offshore currents move water and can affect sediment transport

Coral bleaching

-worldwide whitening -expelling alga -death follow -pollution, disease, sedimentation, salinity changes -1-2 degree warming of sea surface temperatures -end of 2000 30% reefs were lost

How much of the earth's water in found in the Atmosphere?

0.001% of the Earth's water is in the atmosphere as clouds, rain, snow, etc.

Types of Drainage Networks (3)

1. Dendritic 2. Radial 3. Structually controlled

Types of drought (4)

1. Meteorological 2. Agricultural 3. Hydrologic 4. Socio-economic

How ice and snow accumulate in glaciers?

1. Snowflakes pressed together by weight or other snowflakes 2. More snow adds weight and compresses flakes into small spheres 3. Increasing depth and pressure cause snow to become crystalline ice, commonly bluish from trapped air

Formation of sea cave and sea stack

1. promontory extend out into sea 2. weak or fractured rock forms cave 3. continued erosion leads to collapsed roof of cave

Groundwater

30% of the Earth's freshwater

How much air can loose snow contain?

90%

How much surface water does the ocean have?

96.5% of near surface water

Discharge

Amount of water varies with time and is measured in volume per time

Brackish

Between fresh and salty water

Brackish

Brackish < 3.5%

Brine

Brine > 3.5%

Base level

Can be the sea, lake or closed basin, the lowest level to which a river can erode

Hydrologic Cycle

Circulation and transformation of water throughout the Earth's atmosphere, hydrosphere, cryosphere, lithosphere and biosphere

What type of glacier covered the earth during the Pleistocene?

Continental glaciers covered about 1/3rd of the earth's surface

What is the hydrologic cycle composed of?

Currents of water, water vapor, ice and energy flowing continuously in an open plumbing system

Baymouth bar

If a spit blocks a bay

How does a barrier island form

If sea level rises

What does a steep curve indicate in hydrograph?

It indicated a rapid change in flow rate

What happens when ice turns blue?

It is getting buried and compressed

What happens when water evaporates?

It leaves the salt behind so the moisture in the atmosphere is fresh and the rainfall is fresh

Where does the Earth's water move over time?

It moves to the surface such as when magma releases water vapor during eruptions

How does the roughness of landscape reflect the gradient of rivers?

It reflects decreasing gradient of rivers (curved profile)

What does hydraulic pressure do to subglacial channels?

It sometimes forces water to flow upslope

How does contamination spread out?

It spreads out due to diffusion and mixing, forming a contamination plume

Snow line

Lowest elevation where snow remains year round

How did the Earth's water originate?

Most of the Earth's water probably originated during the formation of the planet or from comment and other icy celestial objects

Does water flow downhill?

Not always in glaciers

Streams

Streams carry moving water through one or more channel

Where should the well/septic tank be located?

The well should be uphill of the septic tank but be aware of what is further up the hill

How do scientists measure the amount of water?

They measure the amount of water flowing through a specific measuring site in a stream

How do rivers vary over time?

They vary in discharge, such as peak flow during spring snowmelt or during a raining season that begins in the middle of the summer

Permafrost Structures

Utilidors & Trans-Alaska Oil Pipeline

How does slope of the water table influence Groundwater flow?

Water moves faster if there is a steeper slope to the water table compared to a more gentle slope, if we are comparing the same kind of material with the same permability

What happens to the water table before over pumping?

Water table if fairly flat and water flows to the left, past small well

How do we track and remediate groundwater contamination?

We drill wells to intercept plume and then pump out and treat water then dispose of the contemned water or treat it with activated charcoal or certain geologic materials

How does a badmouth bar form

When a spit cuts off a bay

Why is it important to consider the direction of groundwater?

When sighting the relative positions of a water well and contamination sources, such as a septic tank

Can rivers cut across layers (ridges)?

Yes, for example the Appalachian Mountains

Fjord

a U-shaped valley now flooded when sea level rose from melting Pleistocene ice. Many fjords have bottoms below sea level, testimony to effectiveness of glacial erosion , drowned river valleys

Aquifers

a rock unit that can store and transmit water to a well or spring in useful amounts (porosity and permeability)

Paternoster lakes

a series of lakes along a glacial valley, ribbon

Permeable

allows for the passage of water ex: sponge cake, sand

Lateral moraine

along the sides of the glacier form low ridges along what were the edges of the glacier

Ice sheets

are regionally continuous masses of ice, some ice sheets cover thousands of square kilometers like in Antarctica and Greenland today

Subglacial

below the glacier

Drainage divide

boundary between basins

Dendritic drainages

branches and tree-like with smaller tributaries feeding into larger ones

Sea wall

built along the short and usually constructed of concrete, steel, or some other kind of strong material

Jetty

built out into the water to protect a bay, harbor or nearby beach

Outside of bend in Meander Stream

channel deeper and velocity faster so erosion forms a cutbank

Inside of bend in Meander Stream

channel shallower and velocity lower so deposition forms a point bar

Sea stack

continued erosion can collapse the roof of a cave forming a sea stack

Wave cut platform (crete)

erosion at sea level can bevel off bedrock, forming a flat wave cut platform

Loch Ness

example of a fjord in Scotland

Radial drainages

flow outward in all directions like off a circular mountain

Structurally controlled drainages

follow tilted or folded layers, faults, and joint patterns

Caves and sea arches

form when erosion concentrated in the tidal zone, undercutting cliffs and forming caves, common along uplifted coasts

Sea cliffs

form when hard bedrock eroded to form cliffs, usually fronted by a narrow beach, common where the land has been uplifted

Cirque

formed in part by plucking of rocks by glacier, depression where accumulation happens

Terminal Moraine

forms at the snout of the glacier, marking the farthest downhill extent

Lakes

fresh or salty, most are freshwater lakes but saline or brackish in dry climates

Kettle Lake

from ice block within sediment, ice block melts, burial by fluvioglacial sediment when ice block melts, depression is created. Sometimes filled with water if the bottom intersects the water table

Striations

generally can indicate direction of ice movement but in locations where ice is funneled by local topography, inferring direction from striations may be incorrect

Low Sinuosity Stream

gently curved stream

Valley glaciers

glaciers flow out of the mountain into broader topography, they form piedmont glacier

Alpine glaciers

glaciers in mountainous areas

What does glacial melt water produce?

glaciofluvial deposits

Horn

if a glacier is glacier is glacially eroded on three sides, pyramidal peak

Rivers

important for sources of water and transportation

Where do glaciers form?

in area of permanent snow-high latitudes and high elevations

What do smaller fluctuations in a discharge record mean?

individual events like a storm or especially warm week that results in more snowmelt in the spring

Arete

is jagged and steep because glacially eroded from both sides, sawtooth ridge

Equilibrium line

loses equal accumulations

Barrier island

low islands offshore that act as barriers, partially protecting the coast from large waves

Spit

low ridge of sand and other sediment that extends of the corner of a coast or an island

Sandbar

low sandy area offshore which is submerged much of the time

Hanging valley

main glacier erodes deeper than smaller side glaciers, great site for waterfalls

"melt out" till

material "let down" form supraglaical an englacial positions and not carried away by meltwater would be considered this

Till

material deposited directly by ice and it is typically unsorted, not being washed by meltwater. It can contain both clay and massive boulders in the same deposit -makes for poor gravel deposit because of its unsorted nature

Glaciofluvial deposits

mined for gravel used for road beds, making concrete and glass, spreading on icy roads and other uses

Deep ice

most of the air is squeezed out and it absorbs red and orange more than it does blue. The deeper ice gets the more blue it appears

Braided stream

network of interweaving channels

Impermeable

obstructs water movement ex: clay, butter icing

Moraine deposits

occur through mass wasting of material falling off the glacier into a lower position by shear plains bringing entrained material to the surface and through bulldozing

Plucking

occurs on the down-ice side of bedrock obstructions, striations on the up ice side

Supraglacial

on top of glacier

Unconfined Aquifer

open to the earth's surface and to infiltration, most common type

Confined Aquifer

overlain by less permeable materials, separated from Earth's surface by rocks with low permeability

Hydrograph

plot of discharge versus time

Till plains or ground moraine

relatively flat plains of till, deposited directly from the base of the ice

Recessional and terminal moraine

ridges of glacial sediment marking former terminus

Medial moraine

sediment rich belt in center of the glacier, formed further up ice where 2 branches of the alpine glacier joined

Drumlin

shaped by moving ice, streamlined, only depositional feature created by advancing ice. Steep soss faces up-ice, gentle lee slope faces down ice. Just the opposite of Roche Moutonee

Competence

size of largest particles that can be moved

Tarns

small lakes formed at the base of the cirque, cirque lake

High above sea level

streams and rivers can have steeper gradients and rods sharply into terrain, much erosion

Closer to base level

streams have lower gradient so less erosion

Sediment budget

the amount of sediment available to a system

Down-ice

the side where plucking occurs

Up-ice

the smooth, gentle surface

Firn

the transitional form between snow and ice

Perched Aquifer

underlain by low permeability unit, sits above the main water table

What do moraines consist of?

unsorted deposited till but where the water melted off the glacier, till deposits quickly grade into fluvial deposits

Meandering stream

very curved, high sinousity

Breakwater

wall built out in the water parallel to the shore to bear the brunt of the waves and currents

Groin

wall built out into the water to influence the lateral transport of sand by longshore current

Water within glaciers

water is also in permafrost and ground ice in these areas

Swamps & wetlands

water is on the surface

Artesian Aquifer

water rises some (maybe to surface), has no implication about water quality or taste (some artesian wells are salty water)

Promontory

waves can erode promontory from the 3 sides

Sea caves

weaker parts of the rock behind the top of the promontory may erode faster than the tip forming a cave

Pinnacles and Sea slacks

when erosion is not uniform along the coast line and some rocks are left behind

Roche Moutonee

where the direction of ice can be inferred

Esker

winding ridge of sediment marking former position of subglacial within ice

Englacial

within the glacier