question

Possible consequences of excessive groundwater withdrawal include A. Surface subsidence B. Increasing depth to water table C. Saltwater contamination of groundwater D. All of the above

answer

D

question

Dams on the Chattahoochee (which empties into the Gulf of Mexico) have the following effect on Florida Panhandle beaches: A. improve the quality of the beaches because there are fewer floods damaging the beaches B. increase beach erosion because sediment is trapped behind the dams C. decrease beach erosion because there is less sediment to abrade the beaches D. Has no effect on the beaches

answer

B

question

The concentration of the principle form of C, HCO3-, in river water is about 10 times that of Na+ but the concentration of Na+ in the ocean is about 100 times that of HCO3-. This contrast in behavior exists because: A. HCO3- evaporates rapidly from ocean water B. HCO3- is used by many shellfish to make their shells C. HCO3- is insoluble D. all of the above

answer

B

question

When waves approach a beach at an oblique angle, resulting in a lateral movement of water along the shoreline a ___________ may develop. A. Delta B. Groin C. Sand dune D. Long shore current

answer

D

question

At present, along the eastern coast of the United States, A. Sea level is rising B. Sea level is falling C. Sea level is rising, but the continent is rising faster D. Beaches are being extended seaward

answer

A

question

A sedimentary rock layer that weathers slowly A. will form cliffs B. if tilted, will form valleys C. will form slopes D. all of the above

answer

A

question

Urbanization in a flood plain A. Does not occur because it would be unsafe B. Reduces flood hazards by preventing infiltration C. Has no effect on flood hazards D. Commonly increases flood hazards due to more rapid runoff

answer

D

question

Which of the following contributes most directly to the salinity of the ocean? A. bed load of a river B. suspended load of a river C. dissolved load of a river D. all of the above

answer

C

question

The water table is A. is a perfectly flat surface, hence "water table" B. continuous with the surfaces of lakes and streams C. the zone between the earth's surface and underground streams D. the top of the unsaturated zone

answer

B

question

Typical groundwater flow rates are A. faster than typical stream velocities B. groundwater doesn't flow C. slower than typical stream velocities D. groundwater flow occurs only through caves

answer

C

question

In Bangladesh, arsenic contamination of drinking water is a critical problem because A. The surface waters are contaminated with Arsenic as a byproduct of industrialization B. Groundwater is naturally contaminated with Arsenic and many Bangladeshis drink well water C. Bangladesh is the world-leading producer of Arsenic, and the contamination of groundwater is a byproduct of the mining D. none of the above

answer

B

question

The Mississippi River hypoxic zone is caused by A. industrial chemicals associated with the port of New Orleans B. seepage of oxygen-free gases such as methane from the ocean floor and/or riverbed C. fertilizer application to fields in the drainage basin of the Mississippi River D. all of the above

answer

c

question

Karst topography and caves form due to A. the dissolution of quartz and sandstone B. the dissolution of feldspar and granite C. the dissolution of calcite and limestone D. all of the above

answer

C

question

The Safe Drinking Water Act A. Would have prevented the Woburn tragedy if it had been in effect at the time, and if enforced B. requires minimum standards for wells supplying groups of more than 25 people C. is enforced by the Environmental Protection Agency (EPA) D. All of the above

answer

D

question

The childhood leukemia tragedy in Woburn Ma during the 1960-1970s, was most likely caused by A. surface water contaminated by organic chemicals B. groundwater contaminated by arsenic C. groundwater contaminated by an organic chemical D. None of the above

answer

C

question

When a magma crystallizes or freezes A. several minerals form B. the solid has the same composition as the liquid C. the freezing occurs at a unique temperature, just like ice D. all of the above

answer

A

question

A key aspect to fresh groundwater is A. that it flows B. replenishment of groundwater is a relatively slow process C. it is less dense then saltwater D. all of the above

answer

D

question

Which of the following is true? A. Although the US West is arid, fortunately there is an inexhaustible supply of groundwater available B. Groundwater in the US West is an important source of water but is being depleted by overuse C. Las Vegas golf courses indicate that there is no problem with water resources D Las Vegas waterfalls indicate that there is too much groundwater beneath Las

answer

B

question

A good aquifer is A. porous but not permeable B. permeable but not porous C. permeable and porous D. none of the above

answer

C

question

. local rapid sea level rise near the Mississippi delta is due to A. local uplift of the crust B. global sea level rise alone C. land subsidence alone D. the combined effects of land subsidence and global sea level rise

answer

D

question

You have a chance to build a house on the beach in the panhandle of Florida. Which of the following would not be a wise thing to do A. build the house on stilts B. bulldoze the dunes to improve the view C. Keep the investment in the house relatively low D. all of the above

answer

B

question

The oceans are salty because A. of the dissolved load of rivers B. because of the hydrothermal circulation of sea water through hot springs C. because of evaporation D. all of the above

answer

D

question

The Hawaiian Island chain was instrumental in showing that the Pacific plate moves at about 9 cm per year based on A. the composition of the basaltic lavas B. the age progression of volcanoes in the island chain C. the reversals of the magnetic field D. All of the above

answer

B

question

When a river flows into the ocean, the fresh water usually A. sinks to the bottom B. floats on top of the salt water C. immediately mixes with the salt water D. There is no way to predict the interaction

answer

B

question

The bicarbonate ion, HCO3-, is part of A. the suspended load of a river B. the bed load of a river C. the dissolved load of a river D. all of the above

answer

C

question

The thermohaline circulation A. is limited to longshore currents near beaches B. refers only to deep ocean currents of cold water C. is the ocean encompassing deep and shallow currents driven by salinity and thermal differences D. refers to only the Gulf Stream

answer

C

question

The density of seawater is controlled by A. salinity alone B. temperature alone C. combination of salinity and temperature D. barometric pressure

answer

C

question

. Hypoxia which is a common problem near the world's river deltas, including that of the Mississippi River is due to algal blooms which A. use up the available oxygen during their metabolic processes B. result in oxygen-poor bottom waters due to the decay of the algae C. the bloom covers the water's surface and doesn't allow oxygen to enter the water from the atmosphere D. none of the above

answer

B

question

A key environmental act is the Clean Water Act which applies to the Mississippi River but not to: A. groundwater beneath Woburn MA B. Columbia River C. Appalachicola River D. the Great Lakes

answer

A

question

Carbonic acid, H2CO3 is a common agent in weathering. How does it form? A. from weathering of limestones B. it is a byproduct of the making of shells by organisms C. reaction of water and carbon dioxide in the atmosphere D. all of the above

answer

C

question

. Caves and sinkholes are primarily the result of which reaction? A. Dissolution/deposition of carbonates CaCO3 (calcite) + H2CO3 = Ca2+ + HCO3- B. Weathering of Fe-Mg silicates (not balanced) (Mg,Fe)2SiO4 + H2CO3 + O2 = Mg2+ + Fe2O3 (iron oxide) + HCO3- + H4SiO4[soln] C. Weathering of feldspar (not balanced) (K,Na)AlSi3O8 (feldspar) + H2CO3 (carbonic acid)+ H2O = Na+ + K+ + H4SiO4[soln] + Al2Si2O5(OH)4 (clay)+ 2 HCO3- D. Weathering of sulfides (not balanced) FeS2 (pyrite) + H2O + O2 = 2H+ + SO4-2 + Fe2O3.H2O (iron oxide) E. None of the above

answer

A

question

Dissolution/deposition of carbonates CaCO3 (calcite) + H2CO3 = Ca2+ + HCO3- B. Weathering of Fe-Mg silicates (not balanced) (Mg,Fe)2SiO4 + H2CO3 + O2 = Mg2+ + Fe2O3 (iron oxide) + HCO3- + H4SiO4[soln] C. Weathering of feldspar (not balanced) (K,Na)AlSi3O8 (feldspar) + H2CO3 (carbonic acid)+ H2O = Na+ + K+ + H4SiO4[soln] + Al2Si2O5(OH)4 (clay)+ 2 HCO3- D. Weathering of sulfides (not balanced) FeS2 (pyrite) + H2O + O2 = 2H+ + SO4-2 + Fe2O3.H2O (iron oxide) Which of the reactions contributes to the salinity of the oceans? A. A only B. B only C. none of the reactions D. D only E. all of the reactions

answer

E

question

Dissolution/deposition of carbonates CaCO3 (calcite) + H2CO3 = Ca2+ + HCO3- B. Weathering of Fe-Mg silicates (not balanced) (Mg,Fe)2SiO4 + H2CO3 + O2 = Mg2+ + Fe2O3 (iron oxide) + HCO3- + H4SiO4[soln] C. Weathering of feldspar (not balanced) (K,Na)AlSi3O8 (feldspar) + H2CO3 (carbonic acid)+ H2O = Na+ + K+ + H4SiO4[soln] + Al2Si2O5(OH)4 (clay)+ 2 HCO3- D. Weathering of sulfides (not balanced) FeS2 (pyrite) + H2O + O2 = 2H+ + SO4-2 + Fe2O3.H2O (iron oxide) Acid mine drainage is caused by weathering of ore minerals - which of the above reactions describes the process? A. reaction A B. reaction B C. reaction C D. reaction D

answer

D

question

A. CaCO3 (calcite) + H2CO3 = Ca2+ + HCO3- B. Weathering of Fe-Mg silicates (not balanced) (Mg,Fe)2SiO4 + H2CO3 + O2 = Mg2+ + Fe2O3 (iron oxide) + HCO3- + H4SiO4[soln] C. Weathering of feldspar (not balanced) (K,Na)AlSi3O8 (feldspar) + H2CO3 (carbonic acid)+ H2O = Na+ + K+ + H4SiO4[soln] + Al2Si2O5(OH)4 (clay)+ 2 HCO3- D. Weathering of sulfides (not balanced) FeS2 (pyrite) + H2O + O2 = 2H+ + SO4-2 + Fe2O3.H2O (iron oxide) In Georgia, our soils are notably red as a result of A. reactions A ; B B. reactions B ; C C. reactions A ; C D. reactions B ; D E. all of the reactions

answer

D

question

Based on these reactions which minerals will decrease upwards in a soil profile A. Feldspars B. iron oxides C. clay minerals D. all of the above

answer

A

question

The nature of a soil depends on A. availability of water B. temperature C. nature of bedrock D. all of the above

answer

D

question

At convergent margins which topographic feature marks the location of the plate boundary? A. the line of volcanoes B. the island arc C. the deep sea trench D. all of the above

answer

C

question

Active volcanoes are monitored with seismometers because A. small earthquakes track magma movement B. to monitor seismic activity in the region - it has nothing to do with the volcano C. to monitor deep earthquakes associated with the Benioff zone D. all of the above

answer

A

question

The Moho, the boundary between the crust and mantle was recognized around the world because of: A. reflection of seismic waves off this boundary B. its compositional significance C. the consistent thickness of crust around the world D. all of the above

answer

A

question

40. Which of the following is an example of a stable material persisting at the earth's surface in Athens GA? A. dry ice (frozen CO2) B. the diamond in my mother's engagement ring C. quartz grains in sand bars of the Oconee River D. all of the above

answer

C

question

El Niño-La Niña is a cyclic alternation of cold and warm surface waters off the west coase of South America which is cause by a poorly understood: A. weakening and strengthening of trade winds B. cycling of the earth's magnetic field C. variation in the earth's orbital tilt D. swimming escapades of the same giants that caused the Younger Dryas

answer

A

question

CaCO3 (calcite) + H2CO3 = Ca2+ + HCO3- B. Weathering of Fe-Mg silicates (not balanced) (Mg,Fe)2SiO4 + H2CO3 + O2 = Mg2+ + Fe2O3 (iron oxide) + HCO3- + H4SiO4[soln] C. Weathering of feldspar (not balanced) (K,Na)AlSi3O8 (feldspar) + H2CO3 (carbonic acid)+ H2O = Na+ + K+ + H4SiO4[soln] + Al2Si2O5(OH)4 (clay)+ 2 HCO3- D. Weathering of sulfides (not balanced) FeS2 (pyrite) + H2O + O2 = 2H+ + SO4-2 + Fe2O3.H2O (iron oxide) Which of the reactions contributes to the salinity of the oceans? A. A only B. B only C. none of the reactions D. D only E. all of the reactions

answer

E

question

A. CaCO3 (calcite) + H2CO3 = Ca2+ + HCO3- B. Weathering of Fe-Mg silicates (not balanced) (Mg,Fe)2SiO4 + H2CO3 + O2 = Mg2+ + Fe2O3 (iron oxide) + HCO3- + H4SiO4[soln] C. Weathering of feldspar (not balanced) (K,Na)AlSi3O8 (feldspar) + H2CO3 (carbonic acid)+ H2O = Na+ + K+ + H4SiO4[soln] + Al2Si2O5(OH)4 (clay)+ 2 HCO3- D. Weathering of sulfides (not balanced) FeS2 (pyrite) + H2O + O2 = 2H+ + SO4-2 + Fe2O3.H2O (iron oxide) Acid mine drainage is caused by weathering of ore minerals - which of the above reactions describes the process? A. reaction A B. reaction B C. reaction C D. reaction D

answer

D

question

In the GA-FL dispute over water usage, FL maintains that GA withdrawal of water from the Chattahoochee A. effects the Gulf commercial fishing industry near Appalachicola B. effects the oyster harvest in Appalachicola Bay C. effects beach erosion near Appalachicola D. All of the above

answer

B

question

Volumetrically, the most important site for volcanism is what?

answer

mid-ocean ridges

question

decompression melting occurs beneath A. mid-ocean ridges B. hot spots C. convergent margin volcanoes D. A ; B only

answer

D. A ; B only

question

water is a flux, that is it lowers melting temperature of dry rock material A. true B. false C. water has no effect on melting temperature

answer

A. true

question

Pyroclastic flows or nuee ardentes are a hazard associated with what?

answer

composite volcanoes

question

Continental crust grows by...

answer

volcanism and plutonism at convergent margins.

question

Which of the following exceed all historic eruptions in volume A. certain lava flows of flood basalt provinces B. Pyroclastic flows associated with "supervolcano" eruptions such as Yellowstone C. certain Hawaiian lava flows D. A ; B E. all of the above

answer

D. A ; B

question

Dangerous volcanoes are monitored by what?

answer

tiltmeters, seismometers, GPS positioning instruments, and sampling fumarole gases

question

What are some places that are thought to be hotspots?

answer

Yellowstone, Hawaii, and Iceland

question

The ratio of the volumes of volcanic rocks to plutonic igneous rocks is thought to be about _____.

answer

1:9

question

The source of water in the black smoker hot springs found near mid-ocean ridges is what?

answer

the oceans

question

The atmosphere and hydrosphere are in chemical equilibrium with the igneous and metamorphic rocks produced in the earth's interior. True or False?

answer

False

question

Reaction: H2O + CO2 = H2CO3 Effect?

answer

Effect: cause of the mild acidity typical of normal rain

question

Reaction: CaCO3 + H2CO3 = Ca2+ + 2HCO3 Effect?

answer

Effect: cause of sinkholes

question

Reaction: albite + H+ + H2O = kaolinite (clay) + Na+ + SiO2(in solution) Effect?

answer

Effect: contributes to development of clay-rich soils

question

Reaction: biotite + H+ + H2O = Fe(OH)3 + kaolinite (clay) + K+ + Mg+2 + silica (in solution) Effect?

answer

Effect: cause of red soils & contributes to development of clay-rich soils

question

Reaction: FeS2 + H2O + O2 = H2SO4 + Fe2O3-H2O Effect?

answer

Effect: cause of red soils & acid mine drainage and anthropogenic acid rain are a consequence of this reaction

question

The sand grains in the clastic sedimentary rock sandstone, are held together A. due to the pressure that formed the rock B. by a cement of silica or calcium carbonate C. due to the very high temperature of the earth's interior D. all of the above

answer

B. by a cement of silica or calcium carbonate

question

Deep earthquakes (focus ;150 km deep) occur only at A. Convergent margins B. Divergent margins C. Transform margins D. All plate margins

answer

A. Convergent margins

question

The magnetic anomalies or "stripes" on the sea floor A. are a consequence of the flipping of the earth's magnetic field B. Have their long axis parallel to the mid-ocean ridge C. Are present on both sides of the mid-ocean ridge D. all of the above

answer

D. all of the above

question

Deep Sea trenches A. Are the surface sign of a transform plate boundary B. Are the surface sign of a convergent plate boundary C. Are the surface sign of a divergent plate boundary D. Are unrelated to plate boundaries

answer

B. Are the surface sign of a convergent plate boundary

question

The formation of _________rocks requires high pressures and temperatures in the absence of a melt A. sedimentary B. metamorphic C. igneous D. all of the above

answer

B. metamorphic

question

36. Which of the following planets have a bimodal distribution of elevation? A. Mars B. Earth C. Venus D. all of the above

answer

B. Earth

question

The water coming out of the "black smoker" hot springs on the ocean floor is derived from A. primary magmatic water from the earth's interior B. seawater C. groundwater D. all of the above

answer

B. seawater

question

An earthquake epicenter A. is the area with the greatest shaking B. is the point on the earth's surface above the earthquake focus C. is the point in the earth's interior where the earthquake occurs D. is the CNN studio suffering the greatest shaking

answer

B. is the point on the earth's surface above the earthquake focus

question

Key hazards of Convergent margin volcanoes include:

answer

-Lahars or mudflows -Pyroclastic flows -Ash falls & clouds -Landslides -Climate cooling for largest eruptions

question

Lahars-

answer

-ash & water mix with mud from other sources -can be hot -travels down river valleys at high velocities

question

Ex of a lahar:

answer

1985 eruption and mudflow (lahar) -Nevado del Ruiz Colombia, 23000 dead

question

_____ on Mt Rainier may contribute to lahars during an eruption.

answer

Ice cap (makes lahars more likely to happen)

question

Pyroclastic flow and Cloud hazards: ______ are the problem.

answer

High SiO2 (dacites & Rhyolites) gas-rich magmas

question

How pyroclastic flow and clouds form:

answer

As the magma rises to the surface, pressure decreases and gas exsolves explosively (like a soda can being opened)

question

Dante's Peak (1997, Pierce Brosnan Linda Hamilton; 27% favorable rating rotten Tomatoes) based on eruption of _____.

answer

Mt St Helens In 1980

question

Mt. St. Helens was an example of a ______ during eruption.

answer

volcano collapse

question

Before the eruption of St. Helens, a _____ built up.

answer

bulge (grew at 6 ft a day)

question

Mt. St. Helens' pryoclastic flow went out to about _____.

answer

8 km

question

Eruptions can be classified on basis of ______.

answer

volume of pyroclastic.

question

Tambora, Indonesia volcano eruption:

answer

-erupted 1815 -largest well-documented eruption at 160 km3 - about 71,000 deaths [11-12,000 attributed to eruption] -created the year without summer -Sulfate in Greenland ice core reflectsTambora eruption (and an unknown eruption c. 1810)

question

The "year without summer" :

answer

-coldest decade on record -northern hemisphere temperatures depressed by ~0.5-0.3 degrees C -1816-1818 -created by Tambora, Indonesia eruption

question

-recent ex of climate change bc of volcano eruption: Mt. Pinatubo

answer

-it distributed droplets of sulfuric acid which reflect light and reason for climate cooling -this eruption is the 2 biggest in the last century -effects last for about 2 years (but not tramendous effect)

question

The Italian peninsula:

answer

-convergent margin -Volcanoes and high population densities -subductuion zone volcanoes (subduction is on the east side)

question

Vesuvius Volcano:

answer

-Has a long and violent history -looks like it is more active lately, but we just keep better records now (so it probably just as active many years ago) -Naples is the largest city in the area of Vesuvius

question

How do we monitor volcanoes?

answer

-shape (measured by tilt meters & GPS) -volume -earthquakes track magma movement -gas composition (gas coming out of the ground)

question

Tiltmeter:

answer

-based on changes in water level to indicate tilting of land surface -measure inflation of volcano

question

~75% volcanism @ _____ ~15% volcanism @ _____ ~10% volcanism _____

answer

~75% volcanism @ mid ocean ridges ~15% volcanism @ convergent margins ~10% volcanism intraplate, hot spots, continental rifts

question

~__ hotspots around the world, some such as Iceland are on plate boundaries (but others, e.g. Hawaii, Marquesas are not)

answer

30

question

Hawaiian volcanoes are:

answer

-"shield" volcanoes (build almost totally of lava flows with note gradual slopes) -small cinder cones -Mauna Loa is largest terrestrial volcano -have calderas at their summits

question

Example of hot spot on continents is Yellowstone:

answer

-Volcanism to the west of Yellowstone gets older - this is the track of the hotspot -The park is dominated by thermal springs (the surface manifestation of hydrothermal systems) and yellow pyroclastic rocks -Initiation of the hot spot is recorded by voluminous Basalt flows...the Columbia River flood basalts - erupted from cracks or rifts in the Earth's crust about 15 million years ago

question

Flood basalts:

answer

-eruptions are from fissures or long cracks -tremendous amount of lavas erupted in a short time (like Columbia River the basalts) -some are associated with extinctions

question

Laki flow:

answer

-Largest historic lava flow -Winter T in Europe were1-3 degrees C below normal (bc SO2 forms sulfuric acid droplets in the high Atmosphere that blocks sunlight) -SO2 ; HF poisoned grasses in Europe but especially Iceland - 76% horses, 79% sheep, 50% cattle died; following 2 years 1/3 of population succumbed to starvation

question

Igneous rocks come in two flavors:

answer

volcanic ; plutonic

question

Plutonism (intrusion and crystallization of magmas) beneath the surface accounts for ~90% of the earth's ______.

answer

crustal magmatism. (therefore, plutonic rocks are much more important than volcanic )

question

For every cubic km of volcanic rocks, there is an equivalent __ cubic km of plutonic rocks.

answer

9 cubic km

question

Sierra Nevada Mtns, Ca:

answer

-are made up of plutonic rocks -Outcrops for 35,000 km2 -represents ~1,000,000 km3 of plutonic, igneous rock -this pluton formed over a time span of ~100 million years (ending 80 million years ago) -formed by a convergent margin beneath volcanoes -represents the magmatic roots of volcanoes -this mtn formation required uplift and erosion (which happens bc the asthenosphere flows)

question

Southern Appalachians have numerous _____, which can be more or less spherical or tabular.

answer

plutons (including Stone Mtn. and the Elberton granite)

question

dikes:

answer

-intrusive form -crosscuts layers

question

Sills:

answer

-intrusive form -intrude between layers

question

When you melt the top of an iceberg, portions of the iceberg that were below sealevel are now exposed is an analogy for what?

answer

Lithosphere bends as mass is added (such as beneath a mountain range) but when you remove (e.g., erode) mass, the lithosphere rises.

question

The ______ is analogous to the iceberg and the ______ is analogous to the ocean (but remember the asthenosphere is not liquid).

answer

lithosphere; asthenosphere

question

Hudson's bay:

answer

-At glacial maximum, 20,000 years ago, an immense (~2-3 km thick) ice sheet covered North America and depressed the lithosphere -When the ice melted, the land rebounded (much as 100 m over the last 6000 yr) as evidenced by raised beaches -the closer you get to Hudson's bay, the younger the beaches

question

Earth is unique in its bimodal topography:

answer

-Continental crust is generated in subduction zones,as net additions of volcanic and plutonic material to the crust -Ocean crust is formed at divergent margins -continental crust is lighter (less dense) than the ocean crust (shown in the reaction of the asthenosphere- ocean crust sinks)

question

Age distribution shows growth of continents ______ with time; growth occurs by net volcanic and plutonic addition at convergent margins

answer

outward

question

Why is magmatism abundant on the Earth?

answer

-earth accreted hot, and heat via magmatism continues to escape into space -radioactive decay contributes to heat of earth -mantle is slowly convecting = rising currents -water is introduced into the mantle at subduction zones

question

Melting T of earth materials (rocks, minerals) increases with increasing ______.

answer

pressure

question

Earth materials (rocks, most minerals) are ______ of heat.

answer

poor conductors

question

decompression melting:

answer

-as pressure decreases rising mantle "plumes"reach their melting points -The material can partially melt because the temperature of the mantle is close to its melting T -ex: rising mantle currents occur at hot spots and ocean ridges

question

Why is magmatism abundant at hot spots & ocean ridges?

answer

-"decompression" melting: as pressure decreases rising mantle "plumes" reach their melting points

question

Why is magmatism abundant at convergent margins?

answer

-subducted lithosphere is relatively cold -if you add water, melting temperature is lowered significantly (several 100 degrees) - water is a flux

question

Thermal convection model (shows T of Earth with colors- red and blue):

answer

-the red spots going upward are plumes and cause hot spots -the dark blue spots going downward are subjected lithosphere -flux makes the melting temp. lower (and water is a flux here- lowered it several hundred degrees)

question

_____ creates water-bearing minerals.

answer

Hydrothermal circulation

question

Hydrated, ocean crust is ultimately subducted and releases water:

answer

The subducted lithosphere "Dehydrates", and that water lowers the melting temperature of the mantle and the release of water triggers melting in the mantle at convergent margins

question

The atmosphere and hydrosphere are not in ______ with igneous and metamorphic rocks and many sedimentary rocks.

answer

equilibrium

question

Hydrosphere-

answer

-oceans, rivers, lakes, groundwater, ice -anything made up of water

question

The reaction of rocks with the atmosphere and hydrosphere is _____.

answer

"weathering"

question

What are key culprits of weathering?

answer

H2O O2 (oxygen) H2CO3 (carbonic acid) H2SO4 (sulfuric acid)

question

What are products of weathering?

answer

-new minerals (especially clays & Fe-oxides) -dissolved chemical species

question

Weathering:

answer

-Reactions proceed along cracks/fractures where water penetrates -Dissolution and removal of material is part of the process -Different rocks weather at different rates (-slate tomb stone (black) letters are still visible; limestone (white) the letter are not visible)

question

Resistant, slow-weathering rocks form _____. Fast weathering rocks form ______.

answer

cliffs, "cliff-formers" slopes, "slope-formers"

question

Weathering the Appalachians of Pennsylvania:

answer

-Ridge formed by resistant layer, probably sandstone -Valley underlain by easily weathered rock, probably shale

question

rainwater is slightly acidic due to:

answer

-H2O + CO2 = H2CO3 (formation of carbonic acid in atmosphere -Normal rain has pH = 5.7-6

question

pH = -log [H+] where [H+] is concentration of ______.

answer

hydrogen ion

question

H2CO3, a weak acid, dissociates to H+ and HCO3-, the ______ ion, causing the acidity of natural rain.

answer

bicarbonate

question

H2SO4, a strong acid, dissociates to 2 H+ and SO4-2, the ______ ion.

answer

sulfate

question

Some key pH: 1 M HC l= Acid rain (man-made) = Normal rain is variable (east coast US) = Most streams = Distilled water = Seawater = 1 M NaOH =

answer

1 M HCl =0 Acid rain (man-made) = 2-5 Normal rain is variable (east coast US) = 5.0-5.6 Most streams= 6.0-8.2 Distilled water = 7 Seawater = 8.2 1 M NaOH = 14

question

Rusting:

answer

-FeO +1/2 O2 = Fe2O3 -When exposed to atmosphere...Fe2+ (black or green) becomes Fe3+ (red) -another part of weathering -This reaction is responsible for our red soils

question

Dissolution of calcite: CaCO3 + H2CO3 = Ca2+ + 2HCO3-

answer

-the mineral is completely dissolved -like salt dissolving in water but much slower -leads to the formation of caves, sinkholes and rock pinnacles in land underlain by limestone (like FL)

question

sinkholes:

answer

-FL has many -sinkholes are collapse features -Much of the US (including FL) is underlain by limestones and dolomites -Land underlain by limestone will have surface "dimples" or sinkholes...and is called karst (like in China, Grand Cayman, and Madagascar)

question

stalagmites & stalactites:

answer

-reaction reversed & deposition of new minerals may occur -composed of calcite -this reaction would be going to the right (instead of to the left, like normal) in the formula

question

Pyrite-

answer

-FeS2 -minor constituent in most rock but weathers to sulfuric acid - a strong acid -Key reaction: oxidation of sulfides -Pyrite(FeS2) + H2O + O2 = H2SO4 (sulfuric acid) + Fe2O3.H2O (rust) -Sulfuric acid dissociates immediately to 2H+ & SO4-2 -Acid Mine drainage has a pH of about 1-2 -Sulfides are important metal ores (& pyrite occurs in coals)-so a widespread problem

question

Soil:

answer

-an important product of weathering -Soil = Residual minerals + new minerals + plant debris -Soil commonly has distinct layers or "horizons" -Bedrock is converted to soil very slowly ~ 0.06 mm/yr -Soils vary with climate (rainfall, temperature) & rock substrate -Soil formation is slow, so preserving soil is important, and common sense approaches work such as contour ploughing shown here

question

Mineral that is resistant to weathering?

answer

Quartz

question

______ commonly erodes soils rapidly (typical loss of > 0.1 cm/yr compared to soil growth rate of 0.06 mm/yr)

answer

Urbanization

question

Soil loss widespread but cause varies:

answer

-deforestation -overgrazing -poor agricultural practices -urbanization

question

Hydrologic cycle:

answer

-groundwater and ice reservoirs -ocean

question

What adds water to the hydrologic cycle and subtracts from it?

answer

addition= volcanic gas subtraction= subduction of water bound in minerals

question

Rainfall carried away by ______ that drain into drainage basins.

answer

rivers

question

Does water from the Appalachians come through Athens?

answer

No

question

______ is key parameter for stream/river flow.

answer

Discharge

question

Discharge-

answer

Volume of water passing a point on the bank per unit of time

question

Brevard Fault Zone -

answer

-an inactive transform fault that forms NE-SW Georgia -trending ridges that block drainages

question

Fall line in GA:

answer

-Divides river with falls & rapids from rivers without falls

question

Rivers have passengers:

answer

-dissolved load -suspended load -bed load

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Dissolved load:

answer

-charged ions & uncharged species derived from weathering reactions

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Dead Sea:

answer

-has no outlet -saturated with salt

question

What explains the approximately equal concentration of HCO3- in river water and the ocean?

answer

-ions whose concentration in the ocean is approximately the same as in river water, but must be removed from the ocean by the use of CaCO3 in shell & skeleton making by marine animals -Conversely, ions whose concentrations in the oceans are much higher than in river water are not efficiently removed from solution

question

Bed load:

answer

-is abrasive -erodes the surrounding rock -responsible for features like the Grand Canyon

question

Rivers erode until the riverbed reaches the ______.

answer

base level

question

Rivers meander and create ______.

answer

flood plains

question

The current El Nino:

answer

-will be just as big as the biggest one on record -Will give us a wet and warm winter -Will give CA big storms (water is needed there rn)

question

Incised meanders are indicative of ______.

answer

crustal uplift.

question

flood plains-

answer

-the flat plain surrounding the river -created by the erosive power of the bed load -tend to be very fertile

question

Mississippi has a _____ flood plane.

answer

huge

question

Discharge in Miss. River normally peaks in Spring, why?

answer

Snow melts in April and May causing discharge to rise

question

Why was there a huge rise of discharge in the Miss. River in 1993?

answer

The flood extremely odd and due to heavy Summer rains

question

Natural levees are sandy banks due to...

answer

drop of suspended load during flooding because water velocity drops as it flows out over floodplain

question

100 year flood-

answer

-on average will occur once every 100 years -if you live on the 100 year flood plain, you must buy flood insurance, if mortgage is federally guaranteed -Builders try to stay away from these planes -key concept used in zoning ordinances -based on extension of our observations (not records)

question

Urbanization ______ discharge and ______ time between rain & flooding.

answer

increases; decreases

question

In urbainized places streams over flow more often then they would normally; why and how can we change it?

answer

-There is more run off (due to parking lots redirecting water to streams) -Can reduce this by adding grass to parking lots (like the tate center)

question

How does urbanization affect the reoccurence of the 100 year flood?

answer

100 year flood now occurs more often and is really not the 100 year flood

question

Chattahoochee River debate:

answer

-Important water source for ATL -delivers freshwater to Appalachicola Bay (where FL get their oysters) -debate whether Ga should have to use less water to allow more oysters to grow

question

When river reaches its base level (and velocity drops) bed load is dropped to form the ______.

answer

delta

question

Mississippi drainage basin: note that sediment plume indicates transport to _____.

answer

West (water moves from the east to west)

question

What does Mars have that indicates that there was water?

answer

forms that look like river deltas and meanders

question

Rocks or soils are saturated with water beneath the ______.

answer

water table (which allows groundwater to flow)

question

Porosity-

answer

Empty spaces between grains where fluids can exist

question

Permeability-

answer

measure of connectivity between pores

question

Porosity of gravel:

answer

Well sorted & high porosity

question

Porosity of gravel-clay-sand:

answer

poorly sorted & low porosity

question

Porosity of cemented sandstone:

answer

low porosity

question

Porosity of clay:

answer

high porosity

question

Porosity of limestone:

answer

low porosity

question

Porosity of shale:

answer

low porosity

question

Aquifer-

answer

-a water-bearing rock or gravel/sand/silt unit that is porous & permeable -permit the flow of water -generally are the targets when drilling a well

question

Aquitard-

answer

a rock or gravel/sand/silt unit that is not porous or permeable

question

There is an aquifer in the area btw ______.

answer

rocky mnts and st. louis

question

______ where the Floridan aquifer comes to the surface (good place to go scuba diving).

answer

Wakulla Springs

Geology Test 2: Roden, UGA – Flashcards

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