GEOL 1045: Midterm review

Explain the difference between closed and open systems.

Closed: only energy passes through its boundaries

Open: Matter AND energy pass through its boundaries

What are the 4 Earth systems

Geosphere, Biosphere, Hydrosphere, Atmosphere

Give some examples about how these systems interact

Changes in one system can cause changes in others. (Landslides, volcanoes)

Explain positive and negative feedback loops w/ examples

Positive: Snowball effect, cycle keeps feeding on itself. Deforestation > erosion > loss of vegetation > more erosion.

Negative: Response that decreases change. Warming of atmosphere > evaporation > clouds > cooling.

What are thresholds?

Point of irreversible change

What are the four main categories of environmental geology?

Geohazards, hydrologic processes, use of earth materials, land use planning.

What effect did Mt.Pinatubo have on global temp? Interaction b/w what two spheres?

Global by 0.7°C. Between geosphere and atmosphere.

Scientific Method?

Identify a problem. make observations, develop questions, make hypothesis, test hypothesis.

What is spatial data and GIS?

Data collected on maps, Geographic Information Systems

What info do topo maps show?

Elevation and slope of the land

Describe what happened on Easter island related to environmental sustainability.

Depletion of resources caused by lack of food, deforestation, soil erosion, isolation, no soil nutrients, porous ground, wars.

What happened in Copper Basin, TN?

Deforestation led to severe erosion and lack of vegetation.

Describe how the dust bowl formed.

Major drought dried up farmland.

How does petroleum and natural gas form?

By the slow decomposition of organic materials.

What is meant by “sustainability”?

Avoidance of depletion of resources, To use them wisely

Describe the main layers of the Earth.

Lithosphere (Crust and upper mantle), Asthenosphere (plastic-like), Mantle (solid), Outer core (liquid, generates the magnetic field), Inner Core (solid)

What are characteristics used to identify minerals.

Streak color, hardness, luster, cleavage and fracture.

What is a common ore of copper

Malachite

What are some uses of Calcite?

Soil additive, building material, pharmaceuticals

Name three rock types (and sub types). Give 3 examples of each main type.

Igneous (extrusive, intrusive): Basalt, Andesite, Rhyolite

Sedimentary (clastic, chemical, biochemical, organic): Sandstone, Limestone, Travertine

Metamorphic: Marble, Quartzite, Gneiss

What is the main rock type of the grand canyon and tennessee?

Sedimentary (sandstone, limestone)

Why does gold last so long without tarnishing?

It’s not very chemically reactive. Oxygen doesn’t combine w/ it easily.

What advantage does steel have over iron in building construction?

It’s more durable, doesn’t corrode and rust as easily.

Explain the theory proposed by Alfred Wegener.

Continental drift. All continents were once connected but drifted apart.

What evidence did Wegener have?

Rock and fossil evidence.

Why was Wegener’s theory dismissed?

Lack of plausible mechanism for how they moved apart.

What are the main points of plate tectonics?

Sea floor spreading. Earth’s crust is divided into plates which move past each other.

How were magnetic properties of rocks used to establish timing of sea floor spreading?

You could determine change in time between polarity reversals by seeing the amount of seafloor that spread on the bottom of the ocean between the flips.

Explain the 3 types of plate boundaries.

Divergent (move away), Convergent (move together), Transform (slide across)

What is a hotspot?

Intraplate volcanic activity, not on a boundary.

India/Asia boundary. What mountain was formed?

Convergent. Himalayas.

Iceland boundary/

Divergent (MOR)

San Andreas Fault boundary? Which two plates are separated by it?

Transform. North American Plate and Pacific Plate.

Define following terms: epicenter, focus, seismometer, blind fault.

Epicenter = point on land

Focus = point in the ground

Seismometer = measures magnitude

Blind Fault = doesn’t appear on surface

Name and describe 2 surface and 2 body waves.

P and S: slinky and wavy.

L and R: snake and rolling.

How do you find the distance to the epicenter of an earthquake?

Triangulation w/ seismic stations. Use the gap in time between your P and S waves to determine distance “in circles”. You could then draw three circles around your stations and where those circles meet is the epicenter.

Name 5 potential damaging factors from earthquakes.

Fires, building collapse, liquefaction, landslides, tsunamis.

What is EQ intensity and how is it measured?

Effect of the earthquake on the surface. Roman numerals w/ mercalli intensity scale. Very subjective

What is EQ magnitude and how is it measured?

Amount of movement and strength of rocks. Seismometer and the Richter (Magnitude) scale.

Name these faults.

Normal, Reverse, Stike-slip.

What are the two sides of the normal and reverse fault called?

Hanging wall and footwall.

What is the difference between earthquake forecasting and prediction? Which one is done mostly today?

Forecasting: range of probability

Prediction: No range, just exact time and date.

Forecast is done more often today. Can rely on it more.

What is seismic gap?

A section of a normally active fault that hasn’t slipped in a while.

Paleoseismology?

Study of earthquakes. They gather data along faults to study earthquakes and their intervals

Name 5 mitigation strategies for earthquakes.

Drills, disaster exercises, reinforced buildings, pipeline on rails (structure and foundational stuff), literature.

What is resonance and how does it affect buildings?

When an earthquake frequency matches a buildings sway. It makes the shaking worse.

How does a seismic warning station work?

Seismometer measures activity > sends signal to cell tower > sends signal to satellite > sends data to user of the system.

What are some major events surrounding the Great Kanto EQ?

Fire and racial fallout.

Describe new Madrid EQ’s. What is the probability and risks of it happening again?

Intraplate EQ, 50% of magnitude 6 by 2050. No buildings have been tested, higher population density.

Name 3 lava types, their silica content, and viscosity.

Basaltic: 45-50%, low viscosity

Andesitic: 55-65%, mid viscosity

Rhyolitic: 70-80%, high viscosity

What type of eruptions are most common for each lava type?

Basaltic = effusive

Andesitic = pyroclastic

Rhyolitic = explosive

Difference between strato and shield volcanoes?

Strato: More pointy, mountain like, not super huge. Andesitic or rhyolitic eruptions.

Shield: Large, gentle slopes like hills. Basaltic lava flows.

What is an ophiolite sequence and what does it tell us about rocks near MORs?

Ocean floor volcanic rock gets obducted onto the overriding plate. It tells us what types of rocks are under.

Describe 5 volcanic hazards.

Ash, Lahars, Lava, Pyroclastic Flows, Gas Release.

Describe 5 eruption warning signs.

EQs, small eruptions, changes in temp, shape, and chemistry of ash and steam. Maybe some animal behavior.

How do geologists estimate recurrence intervals of eruptions.

By using paleoseismology. Dating ash layers, lahars, and rock fragments from previous eruptions.

What did a town in Iceland do to approaching lava? Results?

They sprayed water on the lava flow as it got near their town. It kind of worked.

Describe events leading up to Mt.St.Helens. What challenges did officials face trying to forecast the eruption?

Earthquakes, frequent small eruptions, the bulge.

People were skeptical, media broadcasts didn’t help. Logging companies wanted to work.

Main hazard that Mt.Rainier poses?

Lahars.

5 natural service functions of volcanic activity.

Atmospheric cooling, land formation, soil fertilization, geothermal energy, new raw materials.

What effect did a volcano forecast have on Long Valley, CA?

People left, all tourism stopped, 4-6mo period. Ski resorts lost business.

What threat does Yellowstone pose?

Massive eruption. Ginormous ash cloud. Massive EQ.

3 possible causes for flooding.

Snow melt, dam failure, coastal flooding via storm surge.

What is a drainage basin (watershed)

Land area drained by a stream system.

Name the watersheds in the Cookeville area, smallest to largest.

Breeding Mill Branch, Pigeon Roost Creek, Falling Water River, Caney Fork River, Cumberland River.

Deranged water pattern

Glacial area

Explain how flash floods and river floods are different.

Fast rising, minutes to hours

Slow rising, days to weeks

Q = AV.

Flow (m3/s) = area of stream (m2) \* velocity (m/s)

What is the purpose of a river gauging station?

To save time and avoid danger in trying to get data from a river. It monitors the river 24/7.

What 2 variables does a stage rating curve have?

Stream discharge vs. Stage (height)

Acoustic Doppler Current Profiler measures…

discharge of a river.

Which factors go into calculate the shear stress of fluid flowing through a channel?

Fluid density, gravity, depth, slope.

Define bedload, and suspended load

Bedload: When sediment is drug across the bottom of a stream/channel.

Suspended load: When sediment is transported by turbulence (suspended in water)

What is the Rosgen System used for?

To classify different types of channels

Why use T = (n+1) / m?

To find recurrence interval. T = RI. (n+1) = number of years + 1. m = rank order of discharge.

What is the probability of a 100 year flood, 50 year flood?

1%, 2%.

Name 5 flood mitigation strategies.

Levees and flood walls, dams and reservoirs, channelization, channel diversion, floodplain zoning.