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Geo and E Sys Part 3
3rd Part
165
Geology
Undergraduate 2
12/07/2008

Additional Geology Flashcards

 


 

Cards

Term
When were the two greatest floods of the Mississippi during the 20th century?
Definition
1927 and 1993
Term

The last great flood was due to? 

Definition

 

 An excess of rainwater

Happened between June and July, Caused the river to flow more than 500 mi from its main channel, caused 10 billion dollars in damage 

Term
For what 3 reasons are floods/floodplains important?
Definition
  1. Advancement of civilization
  2. To grow crops on (soil is rich)
  3. Build cities on flood plains
Term


 Surface water travels from higher to lower elevations in which 2 ways? 

 

Definition
Rolling over the ground in broad sheets – sheet flow

More commonly by way of depressions- channels, gullies, ruts, valleys where it forms creeks, rills, streams

Term
Some of the factors that cause a stream to flood are??
Definition

If the ground is able to soak up water or if it will have to run off. Intense/long periods of precipitation in combo with:

  1. Melting snow
  2. Inadequate drainage
  3. Water saturated ground
  4. High tides 
Term
Over bank deposits are??  What % of the world’s crops are grown on them?


Definition
During and after flooding water soaks in and/or evaporates. Leaves behind fine deposits of silt and clay – over bank deposits or back swamps, these make the dark fertile soil, crops grown on over bank deposits feed 40% of worlds people
Term
Natural levees are??
Definition
The ridge like deposits that form when a stream rises over bank, its velocity decreases and the heavy materials in the stream fall out
Term
Rivers are important for four main reasons.  These are??


Definition
  1. Highways for transport,
  2.  fresh water,
  3. floodplains for crops and building,
  4. recreation and scenery
Term
A drainage basin is??  The drainage basin for the Mississippi is ------ in size.

 

Definition
Geographic area from which streams and/or a stream system gets water. 1.83 million sq mi
Term
Drainage basins are separated by divides.  These are defined as??  There are 2 kinds of divides- these are??

 

Definition

Topographically high area that separates 2 water sheds

Local (smaller) and Continental (grander scale)

Term
What are the 2 continental divides??

 

Definition
Rocky Mountains-east-west

Laurentian Divide-north-south

Term
Drainage patterns are commonly related to??
Definition
Properties of the surface that the stream flows over
Term
The amount of water in a stream depends on?

 

Definition
Size of drain basin, annual ppt in the area, how water enters the stream-soaks or runsoff
Term
Stream size is defined as?

 

Definition
Volume of water flowing past a given point in a specific period of time-cubic ft/sec
Term
Base level of a stream is??
Definition
Stream needs a slope to flow- so it can only erode down to level of the body of water (base level) into which it flows
Term
The three main ambitions of a stream are??
Definition
Flow, erode, deposit
Term
Streams valleys have V shapes because?  How do these valleys become U shaped??
Definition

Due to mass movement of material down valley walls-top continually widens

 

Glaciers moved down them 

Term
The rate a stream down cuts its channel is dependent on??
Definition
  • Nature of material forming stream bottom
  • Stream velocity=faster teh flow, faster the erosion
  • Scouring and abrading with sediment -sandpaper
  • Composition of water-chemically attacks rocks and dissolves them (Niagara falls)
Term
Stream potholes are?  They form by what method??
Definition
Circular depressions in bedrock by largers rocks that get caught in whirlpools- Eddies, then rotate around and round
Term
Oxbows are?
Definition
Large looping meanders a sizeable detour for the stream
Term
A streams load or capacity is?
Definition
Total amount of sediment carried by a stream
Term
 So-named bed load is? 
Definition
Heaviest materials-pebbles, cobbles, boulders- rolled or pushed along bottom
Term
Saltation is?
Definition
Hopping- Sand hops along bottom, done by roll and impact
Term
Suspended load is?
Definition
Light, fine sediment- can be supported by moving water, gives water cloudy appearance and color
Term
Dissolved load is?
Definition
  • White material in tea kettle, coffee pot
  • Dissolved elements - Ca, Mg, Si, Bi-Carbonate
  • Most abundant where streams occur in warm, moist areas of low relief-soluable bed rock 
Term
Braided streams are?
Definition

Water has high veolicty, no meanders

Mountain streams, large bed load 

Term
Deltas are?
Definition
Rivers into the sea
Term
Alluvial fans are?
Definition
  • Stream velocity decreases dramatically
  • Stream loses most of the sediment it carries
  • This occurs in 2 main place: deserts and rivers that empty into the sea
Term

·         How does a hot spring get hot?

 

Definition
Heat from magma absorbed by rocks and waters of continental and oceanic crust. Geothermal gradient; increase temperature with depth
Term

·         The process by which this happens is??  What does this have to do with Dr. Jeckel and Mr. Hyde?

-         

Definition
Water- raint, river, sea lake

-          Fault, cracks, porous rocks

-          Down it goes, absorbs the heat, expands, light and buoyant, rises up

-          Jekyll (cold, clear, anemic), Hyde (hot, buoyant, rich), full of  many different elements, depends on temperature, composition of water and rocks

Term

·         Some of the places where hot springs occur are? These are places of?  Many of these are located around the so-named Pacific -------?

-       

Definition
  Iceland, New Zealand, Philippines, Japan, Indonesia, Japan…Pacific Ring of Fire

-          All places with recent volcanic activity

Term

·         The heated waters of hot springs may carry a lot of-------.  These can precipitate out of the water in what 3 places.  Depending on where the precipitation occurs it can lead to??


Definition
-          Dissolved stuff

1.       Below ground (mineral deposits)

2.       Above ground (coatings, mud ponds, paint pots)

3.       Atmosphere (pollution-radon, mercury, CO2)

Term

·         The 3 kinds of hot springs are?


Definition
1.       Natural hot tubs (carbonate)

2.       Natural saunas-Steam rooms (Alkali Chloride)

3.       Hot springs from hell (acid)

Term
Carbonate hot springs form??  An example of this would be?


Definition
-          Bubble and fizz (CO2)

-          Carbon Dioxide precipitates out: Travertine, Tuffa, coats things, overflows to form mounds, terraces

Term

·         What was “the 8th wonder of the world?”  What happened to it?  What does it have to do with the Maori phantom canoe?


Definition
-          Tarawara (terraces), on north island of New Zealand, 1886

-          Active volcano

-          Whenever the phantom canoe appears, a disaster is about to happen – 1886, rumor the canoe was present – 10 days later, Mount Tarawara blew up

Term

·         Natural saunas are what kind of hot spring?  What are they good for?


Definition
-          Alkali Chloride (most popular)

-          Wash, cook, relax in – Spas

-          Sodium, potassium, chlorine

-          “Salts” – good for bones, skin, and fatigue – but a lot of them have radon

Term
Hot springs from hell are called this because??  What kind of hot springs are they?
Definition
  • Acid
  • Skin pencil; attacks rocks-clay
Term
Fumaroles are?
Definition
  • No liquid water, but like hot springs
  • Acid -> Vapor-magmatic
Term
Sea floor hot springs occur where? They are typified by 3 distinct features which are?
Definition
  • Mid ocean ridges, subduction zones
  • Down in teh dark, 100's-1000's ft beneath sea, no light
  • Hot springs, mineral chimney's, mounds and lots of fire
Term
Black smokers are?
Definition
Mineral chimneys that shoot out hot water with minerals in them - High temp vent - "black smoke"
Term
White smokers are?
Definition
Low temp mineral chimneys
Term
How big was that chimney?
Definition
Over 200 ft. high!!
Term
Volcanic massive sulfides are? They are major sources of? They form from?
Definition
  • Mounds of circulating hot water
  • Deposits (mineral)
  • Copper,zinc, lead and silver
  • Significant source of gold
  • 3 1/2 bill yrs old
  • Massive when applied to ore- ore consists of 60% or greater by weight of sulfide minerals
Term
Geothermal energy can be used both for electrical power and as a heat source.  The critical difference between the two uses is the -------- of the water.  For generating electrical power the water needs to be ------?
Definition

Temperature

-(150 degrees C)+ 

Term
In what volcanic feature do we find Hot Creek?
Definition
Long valley -> Hot spring
Term
A saturated zone is?
Definition
Referring to groundwater - All space filled with water, top called water table
Term
An unsaturated zone is called?
Definition
Referring to groundwater- Phreatic only some fracture have water in or on
Term
The water table represents what?
Definition
Seprates the two zones (saturated and unsaturated)
Term
A perched water table is?
Definition
A partly saturated, isolated, confined aquifer underlain by an impermeable rock with the main water table below the two
Term
Recharge of the water table is and it occurs?
Definition
  • Soaking in and movement by which ground water is replaced
  • Highest where perosity and permeability are highest
Term
Permeability is?
Definition
Ability to transmit water, How holes connected, clay has high porosity, low permeability = expansive clays
Term
The two best kinds of rocks to contain groundwater are?
Definition
Sandstone and conglomerate
Term
Discharge of groundwater is?
Definition
  • Surface loss of water- Springs, rivers, lakes, wells, etc
  • Recharge- Replace what's lost at discharge
Term
An aquifer is?
Definition

A body of rock that's sufficiently permeable to conduct groundwater and to yield economically significant quantities of water to wells and springs

  • Sandstone best aquifer 
Term
An unconfined aquifer is?
Definition
Overlain by permeable units under no pressure so water rises only to the level of the water table
Term
A confined aquifer is?
Definition

Overlain by an impermeable unit. Vertical movement restricted, under pressure. Water rises upwards above the water table - may come all the way to the surface

  • Artesian well=Confined water
Term
An oasis is?
Definition
Pools of artesian water along a fault zone
Term
What is a "cone of depression"?
Definition
  • Removing more water than is replaced - Pumping
  • Many wells- Water table lowered - Land subsides
Term
Today, glaciers cover how much of the land surface?
Definition
10%
Term
Alpine or Mountain glaciers are?
Definition
  • Local, mountain sides/valleys
  • 3% of Alaska
  • 200,000+ worldwide
Term
What's interesting about a Rhone glacier?
Definition
  • Doesn't move all parts at same rate
  • Source of Rhone River in Switzerland
Term
How much of the worlds fresh water do ice sheets contain and how thick are they?
Definition
85%, 1 mile
Term
Why does ice flow?
Definition
Ice gets so thick it begins to move under its own weight
Term
What causes ice to lose its brittleness?
Definition
  • When it has enough weight on it (165-200 ft of snow) loses brittleness
  • Plastic Flow (Pancake batter) - Flows out under its own weight
  • Flow banding:Soil, rocks in layers, air difference
Term
Crevasses are caused by?
Definition
by tension acting upon the brittle ice; large crack/fracture in the upper surface of a glacier
Term
What are the two places glaciers end up flowing into where they meet their end?
Definition
  1. Flows into water: Weight not supported, breaks up into bergs, Ross Ice Shelf 1987
  2. Warm air: Ice melts faster than glacier can supply it - Advancing, stagnant or retreating glaciers
Term
What's happening to the Larsen and Wilkinson Ice Shelf's and why?
Definition
They're disintigrating and breaking into bergs due to global warming
Term
What is the snow line?
Definition
lower limit of any year's permanent snowfall
Term
What is the zone of accumulation?
Definition
the area of a glacier in which snowfall adds to the glacier
Term
What is ablation?
Definition
The rate of ice loss
Term
What is a retreating glacier?
Definition
Rate of ice loss (Ablation) > Rate of accumulation
Term
What's an advancing glacier?
Definition
Rate of accumulation > Ablation
Term
What's a stagnant glacier?
Definition

Rate of accumulation = Ablation

Front of glacier stays in one place 

Term
Glaciers work 24 hrs a day to?
Definition
Polish, grind, move rocks, dig valleys and basins, bury land under layer of debris, carves up mountains
Term
What are fiords?
Definition
A long, narrow, deep inlet from the sea between steep slopes of a mountainous coast. Fjords usually occur where ocean water flows into valleys formed near the coast by glaciers.
Term
What are horns?
Definition
Pyramidal peaks, near vertical faces on all sides
Term
What's an arête?
Definition
a thin, almost knife-like, ridge of rock which is typically formed when two glaciers erode parallel U-shaped valleys separating the two valleys
Term
What are cirques?
Definition
An amphitheater like valley, situated high on a mountain side near the firn line, and are typically partially surrounded on three sides by steep cliffs
Term
What are hanging valleys?
Definition
a tributary valley with the floor at a higher relief than the main channel into which it flows. They are most commonly associated with U-shaped valleys when a tributary glacier flows into a glacier of larger volume, often waterfalls form at or near the outlet
Term
What are tarns?
Definition
a mountain lake or pool, formed in a cirque excavated by a glacier. A moraine may form a natural dam below a tarn
Term
Instead of making landforms, continental ice sheets do what?
Definition
Bury the land
Term
Abrasion is?
Definition
Rocks picked up from glaciers that scour, grind, and polish
Term
What are striations?
Definition
Thin parallel grooves created by glacial ice that is like sand paper
Term
What is glacial milk?
Definition
Also known as Old Man's Blood/Rock flour - Rocks, as they abrade, get broken down into smaller pieces
Term
What is glacial plucking?
Definition
  • when a glacier erodes away chunks of bedrock to be later deposited as glacial erratics
  • Dig out basins (large and small)
  • Melt water, freezes, pulls out
  • Tooth and string
  • Leads to the formation of basins and whale backs
Term
What are whalebacks?
Definition
Curved rock forms, look like backs of whales - from plucking
Term
Why are glaciers called the garbage cans of the Pleistocene?
Definition
They gobble up everything (soil, rocks, trees, sediment, etc) which all resides in the glacier and when it melts it leaves its mess behind
Term
In what 2 ways do glaciers dispose of the "garbage" they pick up?
Definition
  1. Simply melts: Leaves behind mess, like rude people in movie theaters
  2. Meltwater: Carries tons of sediment away from glacier
Term
What's a glacial erratic?
Definition
a piece of rock that deviates from the size and type of rock native to the area in which it rests, carried by glaciers
Term
What is till?
Definition
  • Sediment from melting glacier deposited in place, no transports
  • Stiff, rocky ground, massive, full of rocks
  • Not layered, poorly sorted
  • Forms the rolling pasture land of MN and New England
Term
Tillite is?
Definition
Lithified till, turned into a rock
Term
Moraines are?
Definition
  • Land forms of till (end, terminal, ground)
  • any glacially formed accumulation of unconsolidated glacial debris (soil and rock) which can occur in currently glaciated and formerly glaciated regions
  • may be on the glacier’s surface or deposited as piles or sheets of debris where the glacier has melted
Term
What is an end moraine?
Definition
Ridges of till at the end of a stagnant glacier
Term
What is a terminal moraine?
Definition
An end moraine that marks the most southern advance of the glacier
Term
What is a ground moraine?
Definition
A broad blanket of till, 10's of 100's mi wide, up to 1000 ft thick, smoothes out landscape
Term
What is outwash?
Definition
  • Melting ice- Water rushes away and carries tons of sediment
  • Creates a whole variety of land froms
  • Layered or bedded, sorted
Term
Eskers are?
Definition
Snake like ridges - Glacial rivers (Melt water rivers that flow beneath the ice, carry lots of sand and gravel, deposits this in channel which becomes clogged, then the stream finds a new route)
Term
Kettles are?
Definition

Depressions which are now lakes, ponds, and prairie potholes

Shallow, surrounded by till 

Term
What are kames?
Definition
Muffin shaped hills
Term
Glacial lakes commonly form behind?
Definition
  • End moraines and edge of retreating glaciers
  • Thus the water is trapped between melting ice and some type of topographic high 
Term
The greatest glacial lake was?
Definition
Lake Agassiz, 50,000 square miles, drained through MN
Term
What was associated with glacial river Warren?
Definition
Catastrophic floods, drained into MN River
Term
How much did the sea levels drop during the last ice age?
Definition
300-400 ft, more than 1/3 of all the land as covered by ice
Term
What are some of the proposed causes of ice ages?
Definition
Axis tilt, plate tectonics, comets and volcanic eruptions, cosmic dust, Milankovitch cycles:Change in orbit, fluctuating CO2 in atmosphere
Term
What is a floodplain?
Definition
Term
Sediment accumulates on the seafloor or lake floor either as --- or ---
Definition
Clay or sand
Term
The most common mineral to be found in sandstone is?
Definition
Quartz
Term
Sandstones are deposited by?
Definition
Wind and moving water (beach deposits)
Term
What is a metamorphic rock?
Definition
An igneous and/or sedimentary rock that has undergone change (been metamorphosed)
Term
What are the 3 changes which causes a metamorphic rock to be formed?
Definition
Heat, pressure, fluid activity (warm/hot water)
Term
Metamorphic intensity (degree of heating up, amount of pressure) is told by...
Definition
Mineral textures
Term
Low grade rocks (low intensity) represent an increase in what?
Definition
Pressure; makes the rocks more tighter together - denser
Term
High grade metamorphism (high temps and pressures) causes minerals to what?
Definition
Align; forms schist, gneiss
Term
About what percentage of the earth's crust do the elements we mine and use make up?
Definition
98%
Term
The most common geological process of the elements and minerals is?
Definition
Hot water - Hydrothermal (ore deposits)
Term
Today the U.S. has --- % of the world's population yet uses --- % of the worlds resources
Definition
6%; 35%
Term
In a stream, where are the best places to look for placer gold?
Definition
  • Behind covered bars
  • In covered rock holes
  • In pot holes below waterfalls
  • On the sides of meander loops
  • Downstream from the mouth of a tributary
  • In the ocean behind bars against the prevailing current
Term
What was the gold rush in Klondike?
Definition
Took place in 1896; George Carmack discovered gold in Bonanza Creek
Term
Today, most industrial diamonds are...
Definition
Synthetic
Term
Why are diamonds so much older than the kimberlite pipes they occur in?
Definition
They were formed before the kimberlite pipes came into existance and then pushed up
Term
What will eventually happen to the diamonds found at the earth's surface?
Definition
They will be moved by running water and accumulated at a placer deposit
Term
How is an earthquake like the cracking of a walnut?
Definition
Sometimes it falls apart easily and is smooth, sometimes it takes more and more pressure until it explodes
Term
Earthquakes occur where?
Definition
Along the edges of plates (mostly), subduction zones, transform faults (San Andreas)
Term
According to the Richter Scale, there is how many big earthquakes and how many destructive earthquakes every year?
Definition
800; 120
Term
Earthquakes do four things which are:
Definition
  1. Break buildings/bridges
  2. Liquify sand, silt and soil
  3. Surface ruptures: Hortizonal and vertical displacement of ground a long faultzone
  4. Ground failure: Earth fissures, mudslides
Term
Amplification of surface waves is much greater on baymud/fill than on...
Definition
Bedrock
Term
The Northridge earthquake in 1964 was more intense than the one in Washington in 2001, why?
Definition
Deep earthquake; severe ground shaking; Washington not a lot a damage, just debris flows
Term
What are some facts about the earthquake in China in 2008?
Definition
7.9 on richter scale; killed 70,000 people; Created mudslides which blocked rivers - evacuated cities because they didn't know if dams would hold
Term
The tsunami of 2005 occured along the...
Definition
Subduction zone; caused the island of Sumatra to move 10 ft.
Term
What planet earth builds up, it tears down with the help of what?
Definition
Weathering, gravity, water and wind
Term
What is the earth's surface constantly doing?
Definition
Remodeling (may be slow or fast, effect on people and earth history)
Term
The rate of movement of a mud flow depends on what two things?
Definition
The slope and the percentage of water
Term
What is weather?
Definition

 Condition of the atmosphere, including: Temperature, precipitation, cloudiness, humidity, wind – At a given place and time

Term
What is climate?
Definition

A composite of weather averaged over many years, there is then Regional and Global Climates

Term
What is global climate?
Definition

Sum of all regional climates through out the earth, a dramatic change in a regional climate can effect the global climate

 

 Ice ages, mini ice ages, deserts, tree species, deep time-fossils, rocks, carbon dating

 

Term
The atmosphere is the key to climate change because?
Definition

It contains Carbon Dionzide and Methane 

They absorb heat rays (infrared heat) heat is emitted by earth materials – rocks, soils, trees, houses, etc.

Term
The two main causes of climate change are??

 

Definition
Natural- Planet earth

Human aided

Term
Overall the four main natural causes of climate change are??


Definition
  1. Volcanoes
  2. plate tectonics
  3. earth’s orbit
  4. objects from space
Term
The four main human causes of climate change are??


Definition
  1.  Burning fossil fuels 
  2. agriculture
  3. sprays
  4. deforestation
Term

The major CO2 culprits are?

 

Definition
  • Power plants (33%)
  • Factories/home heating systems (33%)
  • Cars and trucks (22%)
  • Major transportation  (12%)
Term
What is the cleanest kind of fuel?
Definition
Nuclear
Term
What is the dirtiest/worst kind of fuel?
Definition
Coal
Term

What is happening in Greenland? On Mount Hood?

 

Definition
Ice melting so fast, crevasses are forming all the way down to bedrock; so much melt water under the ice, scared it will start sliding and slide off into the ocean
Term
The countries with the highest emissions are?
Definition
The U.S., Europe, and China
Term
The eruption of Pinatubo in 1991 led to?

Definition
Cold winters; The Perfect storm on east coast, and the halloween snow storm here
Term
When sulfur falls out of the atmosphere, it does so as?
Definition
Acid rain
Term
There is a direct correlation between “acid” content of the glacial ice in Greenland and?
Definition
Global warming!
Term
The Little Ice Age was possible due to?
Definition
Volcanic eruptions
Term
Since 1850, we have had only two large eruptions. This could be due to?
Definition
Global warming
Term
Chlorine contributes to?
Definition
Ozone depletion
Term
The eruption of Tambora in 1815 led to what has come to be called the?
Definition

 The greatest eruption in the last 10,000 years; Indonesia; Strata volcano-Caldera; Year without summer

Term
The eruption of Toba may have brought an end/reduction to what two things?
Definition
A warm interglacial period (ended), and human diversity (reduced)
Term

1.1 billion years ago the edge of the North American continent was in?

 

Definition
Kansas
Term
The most common type of lava flow is?
Definition
Pahoehoe
Term
What are Amygdules?
Definition
form when the vesicular cavities (created by expanding gas bubbles in volcanic lava) are filled with a secondary mineral such as calcite, quartz, chlorite or one of the zeolites, which are deposited by having minerals "wash" through the pores in the rock. They are filled from the outside, making some layered.

Term
The waterfalls in Gooseberry State Park are due to?
Definition
Lava flows
Term
What is the Duluth complex?
Definition

 Intrusive rocks: Magmas trapped in the crust

Term
What is the final advance of the Laurentide Ice Sheet called?
Definition
The Wisconsin Advance; happened 20,000 years ago; the basin filled with ice
Term
During the Wisconsin Advance, the ice began to melt back meltwater became trapped between  what?

 

Definition
Laurentide Ice Sheet and the southeastern and southern edges of the basins
Term
As the Laurentide Ice Sheet continued to melt it did what?
Definition
Shrink, eventually uncovered new outlet in vicinity of Sault St. Marie, because of weight of ice Sault St. Marie area lower than water levels of Lake Duluth
Term
The 3 main exits, for people who traveled by water, from Lake Superior were?

 

Definition
  1. Fond Du Lac
  2. Thunderbay
  3. Grand Portage/Pigeon River (most favored, means “great carrying place”)
Term
What does Grand Portage mean?
Definition
Great carrying place
Term

The kind of rock Split Rock Lighthouse is built on is? This is also called? The rock is unusual because?

 

Definition
Gabbro-lava flow, built on “moon rock” Chilled diabase in contact with Aa flow-topped basalt
Term

·         North America was what in late Pre-Cambrian (1,100,000,000 years ago)

Definition
Laurentia
Term
Continental rifting can lead to the creation of what?
Definition
Ocean basins
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