living w the great lakes EXAM 1
lithosphere
(rigid layer of the earth) -consists of crust and uppermost mantle -strong
what rock types dominate the Michigan basin of the lower peninsula?
(sedimentary rocks) 1. limestone 2.sandstones 3. shales
earths mantle:
(the mantle is approx 1800 miles thick) two parts: 1. Upper Mantle -composed of olivine -more rigid, hard 2. Lower Mantle -similar to upper but has minerals that form only under high pressures -starts getting a softer consistency.. kinda like toothpaste
mid-continent rift
- the earths crust cracks and begins to spread apart -continental rifting has occurred repeatedly in the history of earth -leads to the formation of ocean basins and the fracturing of continents
What early observations were made that lead to the concept of continental drift?
-coasts could fit together like puzzle pieces -implies that they were once joined and later separated
earths core
-composed of metallic iron and nickel -outer core is MOLTEN -inner core is SOLID how do we know this? -studies of earthquakes, meteorites, and density models
mineral (single element or compound)
-naturally formed -inorganic -solid -crystalline structure
rock
-naturally formed, coherent mass or minerals, may include organic debris
Canadian Shield
-precambrian rocks in Canada and the northern great lakes are referred to as the Canadian Shield -composed of granites and metamorphic rocks -2.7 billion years old
how long ago was there rifting in North America? where is this actively going on today?
-rifting activity stopped about 1 billion years ago
what are the 4 major continental divides of North America
1. Great Divide 2. Northern Divide 3. Eastern Divide 4. St. Lawrence Seaway Divide
what are the 3 major rock types?
1. Igneous 2. Sedimentary 3. Metamorphic
what states and provinces make up the Great Lakes watershed?
1. Minnesota 2. Wisconsin 3. Illinois 4. indiana 5. Michigan 6. Ohio 7. Pensylvania 8. New York 9. and the Canadian province, Ontario
how old are the great lakes?
10,000 years old
how is the geologic time scale constructed? (eras and periods)
1800's. geologists began to assemble a theoretical geologic column containing, chronological order, the succession of rock strata
how many watersheds are in the US?
2,110 watersheds
what is the age of the earth?
4.6 billion years
the mississippi river drainage basin carries _________% of the US water flow
40%
the ___________ is not a great lake but it is an important part of the the great lakes system, this creates a system of water flow that leads to the atlantic ocean.
St Clare River
drainage divide
The boundary of a drainage basin; boundary that physically separates the drainage of one drainage basin to another.
continental drift
The hypothesis that states that the continents once formed a single landmass, broke up, and drifted to their present locations -Alfred Wegener proposes the idea of a Supercontinent: Pangaea - suggested earth is broken into pieces and colliding -explains areas of compression and expansion
asthenosphere
The soft layer of the mantle on which the lithosphere floats. (plastic layer) -rock is hotter and flows under pressure
what was the most desired tree species by the lumber industry of the Great Lakes Region during the Lumbering effect? a) white pine b) blue spruce c) evergreen d) oak e) maple
a) white pine
radiometric dating
added numbers to the geologic periods and epochs already defined by stratigraphy
watershed
all of the water that lies beneath the states that connect with the great lakes - area of land where all of the water that is under it or drains off of it goes into the same place (drainage basin)
a watershed is __________________ where all of the water that is under it or ___________ goes into the same place
an area of land; drains off
what is GPS and how does it work
global positioning system -used to determine horizontal position of the lake
which is the shallowest of the great lakes?
lake erie
what small lake is located between lake huron and lake erie?
lake st. clair
which great lake has the largest surface area?
lake superior
which is the deepest of the great lakes?
lake superior
how fast do lithospheric plates move?
large continental plates move less that 2cm a year
the great lakes and their connecting channels form the __________ fresh surface water system on earth
largest
how are ages of rocks determined?
radiometric dating -added numbers to the geologic periods and epochs already defined by stratigraphy
what is precambrian shield?
shields are very old rock from ORIGINAL continents consists of granite rocks and metamorphic rocks
how does SONAR work and what is it used for?
sound navigation and ranging -the sound "ping" is transmitted by an underwater speaker -the time it takes for the sound to travel is measured to determine the distance to the bottom (water depth)
what is a lake shore trap?
the word "trap" originated from a swedish term used to describe stacked lava flows that have weathered to form a STAIR-STEP PATTERN
true or false: each of the great lakes has their own watershed
true
earths crust
two parts: 1. continental crust: -granitic composition -approx 20-25 miles thick 2. Oceanic crust -basaltic composition -approx 4 miles thick
How is bathymetry data collected?
two types of data: 1) GPS (global positioning system) is used to determine HORIZONTAL position of the lake 2) SONAR (sound navigation and ranging) the travel time of the "ping". - determines depth in a large area used to "paint" the bottom
Principle of Superposition
when rocks were placed, newer ones were placed or formed on top of older rocks
igneous rock
a type of rock that forms from the cooling of molten rock at or below the surface examples: bassalt, granite
earths plates ride on circulating currents of hot rock. this process moves the plates and is the product of: a) convection b) transposition c) conduction d) conveyance e) reversion
a) convection
what happens to the amount of dissolved oxygen when the temperature decreases? a) dissolved ox increases b) dissolved ox decreases c) dissolved ox stays the same d) dissolved ox is no longer dissolved
a) dissolved oxygen increases
rocks that crystallize from melts are______________ a) igneous b) metamorphic c) sedimentary d) molten
a) igneous
metamorphic rock
A type of rock that forms from an existing rock that is changed by heat, pressure, or chemical reactions. examples: -marble, gneiss
sedimentary rock
A type of rock that forms when particles from other rocks or the remains of plants and animals are pressed and cemented together examples: limestone, conglomerate
according to plate-tectonic history, plates of rigid, elastic _____________ move over a weak plastic layer below a) lithosphere b) asthenosphere c) mantle d) core
a) lithosphere
the Great Lakes, in order from largest to smallest are:
Lake Superior Lake Huron Lake Michigan Lake Erie Lake Ontario
a rock is__________________ a) a naturally occurring, solid chemical or compound b) a solid, cohesive aggregate of one or more minerals c) the same thing as a mineral d) a mineral that consists of a single element
b
if you found 3 ppm D.O when testing the water, which of the following did you find? a) 3 parts per million of dirty oxygen b) 3 parts per million of dissolved oxygen c) 3 parts per million of digested organisms d) 3 parts per million of diluted oxides
b
what river connects Lake Superior and Lake Huron? a) deep straights of Mackinaw b) St Marys river c) Niagra Falls d) detroit river e) st clair river
b) St Mary's River
which of the following is the thinnest layer of the earth? a) outer core b) crust c) mantle d) inner core
b) crust
what two lakes are considered to be one lake hydraulically with lake levels rising and falling together? a) superior and huron b) michigan and huron c) superior and michigan d) erie and michigan e) there are no lakes that border wisconsin
b) michigan and huron (because they both basically connect to each other)
an excess of fertalizers which contain nitrogen (N) and phosphorous (P) can cause____________ a) magnificent flowers to grow along water b) animals to grow at an alarming rate c) eutrophication d) toxification
c
if acid rain falls into a lake with very good alkalinity or buffering capacity what would happen? a) the pH would drop and become acidic b) the pH would rise and become more alkaline c) the pH would stay about the same d) alkaline has nothing to do with pH
c
approx how many years ago did the first inhabitants arrive in the Great Lakes Region? a) 1 million years ago b) 100,000 years ago c) 10,000 years ago d) 1,000 years ago e) last year sometime
c) 10,000 years ago
which of the following is an example of an igneous rock? a) sandstone b) shale c) basalt d) limestone
c) basalt
what are earths concentric layers
crust: continental and oceanic mantle: biggest layer outer core: molten inner core: solid
what highly prized fur was the widley sought after by the Europeans and an important part of french fur trade era in the great lakes region? a) mink b) deer c) raccoon d) beaver e) fox
d) beaver
rocks that are formed by the crystallization of new minerals in the solid state (without melting) due to heat and/or pressure are _________ a) igneous b) sedimentary c) ultramafic d) metamorphic
d) metamorphic
which is a quantitative measure of the amount of particulate in water? a) secchi b) dissolved oxygen c) conductivity d) turbidity e) none of the above
d) turbidity
water flows ________ through _________ ___________
downward; topographic lows
earths history is subdivided into ______, which are subdivided into _____, which are subdivided into _____, which are subdivided into _____.
eons - eras- periods - epochs
approx how much water is in the great lakes?
estimated 6 quadrillion gallons of water - 1/5 of the words fresh surface water supply