Geology Lab Exam 2
Winds of Hurricanes: (MPH)
- <38 : Tropical depressions - 38 - 74 : Tropical storm - >74 : Hurricanes
Two categories of glaciers:
- Alpine glaciers - Continental glaciers
Types of sand dunes:
- Barchan dunes - Transverse dunes - Bachanoid ridge dunes - Parabolic dunes - Longitudinal (linear) dunes
Beach Composition:
- Berms - Beach Face - Makeup of beaches
Erosional features of a glacial region:
- Cirque - Arete - Col - Horn - Headwall - Glacial trough - Hanging valley - Roche Mountonnee - Glacial striations and grooves - Glacial polish
Mountain glaciers are characterized by:
- Cirque glaciers - Valley glaciers - Piedmont glaciers - ice caps
5 main kinds of glaciers:
- Cirque glaciers - Valley glaciers - piedmont glaciers - Ice sheets - Ice caps
What three methods can be used to determine what type of quadrangle a map is (EX: 7.5 minute quadrangle)
- Look at the title - scale - subtract the longitude printed in the upper left corner from the longitude printed in the upper right corner.
Depositional features of glaciated regions:
- Moraines - Drumlin - Kame -Esker - Erratic - Boulder train - Outwash - Outwash plain - Valley train - Beach Line - Glacial-lake deposits - Loess
Destruction of Hurricanes:
- Storm surge - Wind Damage - Heavy rains and inland flooding
Types of channels:
- Straight - Meandering - Braided
Water bodies o glaciated region:
- Tarn - Ice dammed lake - Paternoster lakes - Finger lake - Kettle lake (kettle hole) - Swale - Marginal glacial lake - Meltwater stream - Misfit stream - marsh or swamp
Shoreline Processes:
- Wave Erosion (abrasion) - Sand Movement on Beaches - Movement Perpendicular to shoreline - Wave Refraction - Longshore transportation (beach drift, longshore current) - Rip Currents
Tow principal types of stream erosion:
- downcutting - lateral erosion
Erosion in arid regions is different from erosion in humid regions due to:
- little precipitation - sparse vegetation - lack of abundant soil cover - local byt intense storms (flash floods)
Rules for contouring:
- must e closed (but may run off the map) - can never cross one another - moving from one line to another indicates a change in elevation - closer together means steeper slope - circle represents hills or closed depression (hachured marks) - crossed streams valley with a V shape; points in direction of stream flow.
Human modification of shorelines: (geoengineering techniques)
- sea wall - Breakwater - Groin - Jetties
Types of drainage patterns:
-Dendritic - Trellis - Radial - Rectangular
Types of landforms associated with deserts:
-Inselberg - sand dunes - bajada - playa - alluvial fans - saltflat - Block faulting
What type of map shows a larger map area a 30', 15' or 7.5' map?
30'
The sawing and grinding action of the water armed with rock fragments.
Abrasion
(Pacific ocean) Relatively narrow beaches that are backed by steep cliffs and mountain ranges. High relief, less sand on coastline, has cliffs, represents a tectonically active.
Active margin
A large wedge of sediment that is deposited at the base of a mountain. this is due because of a stream flowing from a steep mountain into a flat valley experiences an abrupt drop in speed due t the decrease in gradient and cannot transport the same sediment load.
Alluvial Fan
Fan shaped, delta like deposits of sediment that develop where the flash floods and mudflows empty into the valley.
Alluvial Fans
Form in mountain ranges where snow is abundant at high altitudes
Alpine Glaciers
Geologic materials which have both high porosity and permeability (sand, sandstone, gravel and limestone)
Aquifer
Sharp, jagged, knife-edge ridge between two cirques or glaciated valleys
Arete
Relatively flat and slope gently seaward with barrier islands which absorb energy of waves during a storm. PASSIVE continental margin
Atlantic
Form when barchans dunes are numerous and the horns of adjacent barchans dunes merge into transverse ridges. these are chains of the short crescent shaped segments that are the crests of individual barchans dunes.
Bachanoid ridge dunes
When alluvial fans coalesce.
Bajada
Printed in the lower margins of the graph. they are rulers for measuring distances on the map (miles, feet, kilometers and meters)
Bar scales
crescent shape dunes whose tips point downwind that occur where sand supply is limited and wind direction is fairly constant.
Barchan dunes
A long, narrow island that parallels the mainland coastline and is separated from mainland by a lagoon, tidal flat or salt marsh.
Barrier island
Which is the wet sloping surface that extends from the berm to the shoreline.
Beach Face
The zigzag pattern of water movement used to transport sediment along the beach.
Beach drift
Landward edge of a shoreline of a lake formed from damming of glacial meltwater or temporary ponding of glacial meltwater in a topographic depression
Beach line
a gently sloping deposit of sand or gravel along the edge of a shoreline.
Beaches
Sediment that is transported through longshore current is transported and may be deposited in sheltered areas to form _____, _____ and ______
Beaches, barrier islands and spits
Is the compass direction along a line from one point to another.
Bearing (compass bearing)
If the bottom of the sinkhole is _______ the water table, a lake will form.
Below
A permanent marker (usually a metal plate) which has the notations "X" and shows the exact elevation at a certain point that has been tested.
Bench mark
The highest part of a beach, it separates the foreshore (seaward part of the shoreline) from the backshore (landward part of the shoreline).
Berm crest
relatively flat platforms often composed of sand that are adjacent to coastal dunes or cliffs and marked by a change in slope at the seaward edge.
Berms
a type of regional rock deformation where earths crust is broken into fault bounded blocks of different elevations.
Block faulting
A line or band of boulders and smaller rock clasts transported by a glacier and extending from the bedrock source where they originated to the place where the glacier carried them.
Boulder train
consist of numerous channels divided by sediment bars which occur in areas with large amounts of sediment which the stream does not have the capacity to transport.
Braided streams
An offshore wall constructed parallel to a shoreline to break waves. the longshore current is halted behind such walls, so the sand accumulates there and the beach widens. Where the ______ is used to protect a harbor from currents and waves, sand often collects behind the ____ and may have to dredged.
Breakwater
Calculating stream gradient:
Change in elevation/ distance
Bowl-shaped depression on a high mountain slope, formed by a cirque glacier
Cirque
Horns form from ______
Cirque glaciers
Small, semicircular to triangular glaciers that form on the sides of mountains. If they form at the head of a valley and grow large enough then they evolve into valley glaciers.
Cirque glaciers
Type of alpine glacier the is small and forms near the peaks of mountains
Cirque glaciers
are one of the most dynamic areas on the earths surface where erosion and deposition occur continuously as energy from waves and coastal currents work to modify the coastline.
Coast
landward limit of highest storm wave
Coastline
Mountain pass formed by the headward erosion of cirques
Col
are much larger often covering large parts of a continent
Continental Glaciers
Is specified at the center of the bottom margin of the map. this indicates the elevation change between each contour line. (Five countour lines for every 200ft = 40 ft _______)
Contour Intervals
connects all points on the map that have the same elevation above sea level.
Contour lines
Open fissures that form when the velocity of ice flow is variable
Crevasses
the outer bank on the outside of a meander channel. this is where water velocity and turbulence are greater causing erosion.
Cut Bank
The trident shaped symbol on the bottom margin of topographic maps which shows the difference in degrees between compass north (MN)(Magnetic North) and true north (star symbol)
Declination (magnetic declination)
a sediment deposit at the mouth of a river where it enters an ocean or lake.
Delta
The pattern that tends to resemble a branching tree. Occurs if the rock is homogeneous.
Dendritic
are characterized by having a lack of moisture which leads to a restriction on the number of living things that can exist there. Wind directly affects the land surface by removing soil and sediment at the Earths surface along with running water.
Deserts
surface water may appear as natural springs that flow as streams for some distance and then reenter the ground through a fracture or sinkhole.
Disappearing streams
Makeup of Beaches
Dominantly quartz grains and other miners abundant in the area. Can be made up of shell fragments and remains of organisms. Volcanic islands are made of weathered grains and basaltic lava
deepens the alley toward the base level
Downcutting
An elongated mound or ridge of glacial till that accumulated under a glacier and was elongated and streamlined by movement (flow) of the glacier.
Drumlin
coordinates that are the west to east distance in meters within the UTM zone where the central meridian is assigned a false easting of 500,000 meters.
Easting
Is one that is advancing (moving out into the water: prograding) this can occur when sediment and reefs build up to sea level and then build seaward. It can also occur when sea level actually falls globally or when the seafloor rises (uplift which can occur because the region is tectonically active). It can also occur where the crust and mantle are rebounding upward after an ice sheet melts from atop them.
Emergent coastline
Coasts where sea level has dropped. this results in exposure of previously submerged features such as reefs and characterized by rock with steep slopes
Emergent coastlines
Boulder or smaller fragment of rock resting far from its source on bedrock of a different type.
Erratic
Long, narrow, sinuous ridge of stratified drift deposited by meltwater stream flowing under glacial ice or in tunnels within the glacial ice.
Esker
a river valley flooded by a rise in the level of an ocean or lake.
Estuary
Long narrow lake in a glacial trough that was cut into bedrock by the scouring action of glacial ice and usually dammed by a deposit of glacial gravel.
Finger lake
After flood water spill over the banks, they spread across flat planar areas know as _______ adjacent to the channels
Floodplains
In their upper reaches streams have steep V shaped valleys, while downstream the valleys decrease in steepness, become wider and _______ are deposited
Floodplains
Another way of expressing the ratio scale which indicates how much smaller something is than its actual size on the ground. (1/24,000)
Fractional Scale
How do Tarn lakes form?
From Cirque glaciers
_________ causes a U Shape.
Glacial erosion
When more snow accumulates during the winter months than melts during the summer months, snowflakes are compacted over time and recrystallize under pressure to form ______
Glacial ice
Layers of sediment in the lake bed, deltas or beaches of a glacial lake
Glacial lake deposits
Smooth bedrock surfaces caused by glacial abrasion (sanding action of glaciers analogous to sanding of wood with sandpaper)
Glacial polish
Parallel linear scratches and groves in bedrock surfaces, resulting from glacial scouring.
Glacial striations and grooves
U-shaped, steep-walled, glaciated valley formed by the scouring action of a valley glacier.
Glacial trough
a body of moving ice
Glacier
is a measure of the steepness of a slope. (relief/distance from A to B)
Gradient
A short wall constructed perpendicular to shoreline to order to trap sand and make or build up a beach. sand accumulates on the up current side of the ____ In relation to the longshore current
Groin
Sheetlike layer (blanket) of till left on the landscape by a receding (wasting) glacier
Ground moraine
Glacial trough of a tributary glacier, elevated above the main trough
Hanging wall
Projection of land that extends into an ocean or lake and generally has cliffs along its water boundary
Headland with cliffs
Steep slope or rock cliff at the upslope end of a glaciated valley or cirque
Headwall
Steep-sided, pyramid-shaped peak produced by headward erosion of several cirques
Horn
Form in all tropical waters (warm and moist air) (except: South Atlantic and Eastern South Pacific)which involve heavy winds due to fueled energy liberated when huge quantities of water vapor condense. Diminish in intensity whenever they move across cooler ocean water or move across land.
Hurricanes
a vast, pancake-shaped ice mound that covers a large portion of a continent and flows independent of the topographic features beneath it and covers an area greater than 50,000km. The Antarctic _____ covers the entire continent of Antarctica and the Greenland _____ which covers Greenland.
Ice Sheet
A dome shaped mass of ice and snow that covers a flat plateau, island or peaks at the summit of a mountain range and los outward in all directions from the thickest part of the cap. It is much smaller than an ice sheet.
Ice cap
Lake formed behind a mass of ice sheet and blocks that have wedged together and blocked the flow of water from a melting glacier and/or river.
Ice dammed lake
Alpine glaciers that cover one or more peaks
Icecaps
The heavy brow contour lines that have elevations printed on them. These are the starting point when reading elevations on a topographic map.
Index contour
island mountains in the desert that form when alluvial fans surround outlying portions of the mountain fronts. (little mound that points out of the alluvial fan)
Inselberg
Long walls extending from shore at the mouths of harbors and used to protect the harbor entrance from filling with sand or being eroded by waves and currents. They are usually constructed of boulders and in pairs.
Jetties
A low mound, knob or short irregular ridge of stratified drift sorted by the deposited from meltwater flowing a short distance beneath, within or on top of a glacier.
Kame
the landscape that produces due to soluble rock.
Karst topography
Small lake or water saturated depression in glacial drift, formed by melting of an isolated, detached block of ice left behind by a glacial in retreat or by the collapse of an ice dammed lake.
Kettle lake (kettle hole)
What type of erosion is associated with a wide floodplain?
Lateral Erosion
What is the primary type of erosion associated with meandering streams?
Lateral erosion
which widens the valley walls
Lateral erosion
A body of rock (till) fragments at or within the side of a valley glacier where it touches bedrock and scours the rock fragments from the side of the valley.
Lateral moraine
Unstratified sheets of clayey silt and silty clay transported beyond the margins of a glacier by wind and or braided streams.
Loess
Dunes that form where sand is abundant and crosswinds merge to form these high, elongated dunes. they can be quite large.
Longitudinal (linear) dunes
Waves usually approach the coast at an angle and some of their energy generates a current called a ______ which flows parallel to the shore.
Longshore current
is a flat representation of part of Earths surgace as viewed from above and reduced in size to fit a sheet of paper or computer screen.
Map
Lake formed at the edge of a glacier as a result of accumulating meltwater.
Marginal glacial lake
a elevated wave cut platform that is bounded on its seaward side by a cliff or steep slope. (emergent coastline)
Marine terrace
Saturated, poorly drained areas that are permanently or intermittently covered with water and have grassy vegetation (marsh) or shrubs and trees (swamp)
Marsh or swamp
When meanders become so sinuous that the thin area of land between two meanders is cut through _______ is formed.
Meander cut off
What channel type usually forms where streams that have a flatter gradient?
Meandering
A long narrow body of rock fragment (till) carried in or upon the middle of a valley glacier and parallel to its sides, Usually formed by the merging of lateral moraines from two or more merging valley glaciers.
Medial Moraine
Stream of water derived from melting glacial ice, that flows under the ice, on the ice, along the margins of the ice or beyond the margins of the ices.
Meltwater stream
How do medial moraines form?
Merging of lateral moraines
Streams that is not large enough and powerful enough to have cut the valley it occupies.
Misfit stream
parallel hills that form as a result of repeated river flooding.
Natural Levees
Stratified drift transported, sorted and deposited by meltwater streams flowing in front of the terminus of the melting glacier.
Outwash
Plain formed by blanket like deposition of outwash formed by the coalescence of many braided streams having their origins along a common glacial terminus.
Outwash plain
The cut off meander forms a crescent shape lake which may eventually be filled with fine grained sediment and organic matter.
Oxbow Lake
a way to divide public land of the western frontier into small parcels that could be transferred to ownership by private citizens. It is a square grid system centered on any one of dozens of principal meridians and base lines. Each grid is 6 miles by 6 miles.
PLSS (public land survey system)
Relatively narrow beaches that are backed by steep cliffs and mountain ranges ACTIVE continental margin
Pacific
Somewhat resemble barchans but the horns point in the opposite direction upwind. form adjacent to blowouts, oval depressions from which come the sandy sediments that form the parabolic dunes
Parabolic dunes
(Atlantic coastline) relatively flat and slope gently seaward with barrier islands which absorbs energy of waves during a storm. greater amount of sand on coastline, barrier islands, more vulnerable to a rise in sea level, more affected by tides.
Passive Margin
Chain of small lakes in a glacial trough
Paternoster lake
The ability of a formation to transmit water. The ease in which water can flow through.
Permeability
Mergers of two or more valley glaciers at the foot (break in slope) of a mountain range.
Piedmont glaciers
is a flat representation of earths surface that shows horizontal (two dimensional) positions of features like streams, landmarks, roads and political boundaries.
Planimetric map
Ephermeral bodies of water where water meets at the base of the valley. This is where chemicals become more and more abundant as the water evaporates from it. (temporary lakes because of infrequent rain)
Playa
Are along the inside of a meander where water velocity is less and allos for sand or gravel to be deposited
Point bar deposits
The percent volume of open space in a geologic formation
Porosity
is a relatively rectangular area of Earths surface bouded by lines of latitude at the top and bottom and by lines of longitude on the left and right.
Quadrangle
is a section of the Earths surface that is bounded by lines of latitude at the top and bottom and by lines of longitude on the left.
Quadrangle
Drainage patterns in which streams may radiate away from a central point.
Radial
Commonly expressed above the bar scales in the bottom margins of topographic maps and express the ratio of a linear dimension on the map to the actual dimension of the same feature on the ground (in real life) (1:24,000)
Ratio scales
Ridge of till that forms at terminus of a glacier, behind and generally parallel to the terminal moraine; formed during a temporary halt in recession of a wasting glacier.
Recessional moraine
Drainage patterns in which streams follow channels through fractured rock.
Rectangular
is the difference in elevation between landforms, specific points or other features on a landscape or map
Relief
concentrated movements of water that flow in the opposite direction of breaking waves (rip tides)
Rip Current
Asymmetrical knoll or small hill of bedrock, formed by glacial abrasion on the smooth stoss side (side from which the glacier came) and by plucking (prying and pulling by glacial ice) on the less smooth lee side (down-glacier side)
Roche Mountain
________ is the primary geologic erosional agent in the deserts which is the primarily responsible for molding desert landscapes.
Running water
a white, soggy or dry level patch of land that is encrusted with salt that forms when a playa evaporates
Salt flat
a marsh that is flooded by ocean water at high tide. (emergent coastlines)
Saltmarsh
an embankment of boulders, reinforced concrete or other material constructed against a shoreline to prevent erosion by waves and currents
Sea wall
Each township square is also divided into 36 small squares with each having an area of 1 square mile (640 acres). These square mile subdivisions of land are called ____ (1 begins in upper right corner of township)
Sections
line that marks contact between land and sea
Shoreline
If the cave is near the surface a _______ develops if the ceiling of the cave collapses (this appears on a topographic map as a nearly circular depression)
Sinkhole
Is the elevation above which there is permanent snow cover
Snowline
a sand bar extending from the end of a beach into the mouth of an adjacent bay.
Spit
an isolated rocky island near a headland cliff (submergent coastlines
Stack
Is a dome of water 65 to 80 kilometers wide that sweeps across the coast near the point where the eye makes landfall.
Storm Surge
Is an abnormal rise of water pushed landward by high winds and/or low atmospheric pressure associated with storms.
Storm surges
the water level height caused by a combination of the normal tide level and the storm surge.
Storm tide.
_______ channel streams usually have steep valley walls.
Straight
channel streams occur in steep areas and erode their channels mostly by downcutting
Straight channels
Is one that is being flooded, eroded back or is otherwise receding (moving landward) This can occur on short timescales due to erosion by waves but it also occurs over longer periods of time due to sea level rise.
Submergent coastline
Coast which have undergone sea level rise which have features such as drowned river valleys and depositional landforms such as beaches and barrier islands.
Submergent coastlines
Narrow marsh, swamp or very shallow lake in a long shallow depression between two moraines
Swale
Small lake in a cirque.
Tarn
Ridge of till that formed along the leading edge of the farthest advance of a glacier.
Terminal moraine
Why are some sinkholes dry?
They are above the water table
Muddy or sandy areas that is covered with water at high tide and exposed at low tide (emergent coastlines)
Tidal flat
An island connected to the mainland or another island by a tombolo. (submergent coastline)
Tied island
a sand bar that connects an island with the mainland or another island (submergent coastlines)
Tombolo
Why are there few sinkholes in a part of a topographic map that have little or no sinkholes?
Too high of elevation
is a cross section that shows the elevations and slopes along a given line. (elevation on Y axis and distance on X axis)
Topographic profile
refers to the surface features on an area of land
Topography
The north-south squares of the grid in PLSS (T1S: _____ 1 South)
Townships
dunes that occur where sand supply is greater. they form as long ridges perpendicular to the prevailing wind direction.
Transverse dunes
Drainage patterns in an area of linear ridges and valleys, streams mostly follow the valleys but larger streams may cut through the ridges.
Trellis
A rectangular grid that measures in decimal based metric units (meters and Km)
UTM (universal Transverse Mercator system)
As cirque glaciers grow larger they become ______ as they flow downslope, usually in stream valleys.
Valley glaciers
Long glaciers that originate at cirques and flow down stream valleys in the mountains.
Valley glaciers
Long, narrow sheets of outwash that extends far beyond the terminus of a glacier.
Valley train
stretching of the vertical scale of a topographic profile to make landscape features more obvious. found by dividing vertical fractional scale by horizontal fractional scale)
Vertical exaggeration
a fan shaped deposit of sand or gravel transported and deposited landward of the beach during a washover of the land or island during a storm or very high tide.
Washover fan
a bench or shelf at sea level along a steep shore and formed by wave erosion. (emergent coastlines)
Wave cut platform
The bending of waves
Wave refraction
a seaward facing cliff along a steep shoreline, produced by wave erosion (submergent coastlines)
Wave-cut cliffs
______ beaches are associated with emergent coastlines.
Wide
Tributaries that flow parallel to the main stream channel which are caused my large floodplains
Yazoo streams
Groundwater flowing through natural fractures dissolves the surrounding rock creating a ______
cave
Describe the gradient of a stream that forms oxbow lakes, back swamps and point bars.
flat
How are moraines formed?
glacier deposits sediment
the slope along which a stream descends.
gradient
Water from rain or streams which infiltrates below the surface. May be stored in fractures, pores, caves and other open spaces in geologic materials.
groundwater
Desert landscapes evolve from an area of ______ relief to one of ______ relief
high low
Very detailed but covers a small area
large scale
most widespread example of soluble rock composed of calcite.
limestone
occur in flat areas and exhibit mainly lateral erosion
meandering streams
in the lower reaches of a stream where the gradient is less, a stream will swing from side to side across the valley floor forming hairpin loops known as _______
meanders
______ beaches are associated with submerging coastlines
narrow
Coordinates is the distance from the Equator measured in meters for UTM
northing
The east-west squares of the grid (R2W: _____ 2 West)
ranges
The sea level is _____
rising
Ratio of a distance on the map to the actual distance on the ground. It is the proportion by which you reduce the real area to map size.
scale
not as detailed but covers a large area
small scale
Groundwater will shape the landscape most when _______ rocks (those composed of minerals that readily dissolve in water) are at or near the surface.
soluble
multiple sinkholes may merge to form a larger ________
solution valley
If sea level rises, what would happen:
storm surges and storm tides rise.
Shows the same horizontal information as a planimetric map but also includes contour lines to represent elevations of hills and valleys making it appear 3D.
topographic map