question

How many Mass Extinctions have there been? In what eras? What is their relationship to relative timescale?

answer

There have been 5 - two in the Paleozoic, one between the Paleozoic and the Mesozoic, one in the Mesozoic, and one between the Mesozoic and the Cenozoic. They are related to relative time scale as the mass extinctions typically signal a large change in speciation and life on Earth at that time

question

What was the Ordovician-Silurian Extinction?

answer

It was the first mass extinction, happened during the Paleozoic era, about 80% of marine species became extinct over about 20 mil years, likely associated with cooling of the global climate

question

What are some of the consequences of cooling the planet?

answer

More water stored in ice sheets, less continental shelf which is bad because ocean life likes shallow seas, changes in ocean chemistry, less food for heterotrophs

question

What was the Permian-Triassic Mass Extinction?

answer

Third mass extinction, happened between the Paleozoic and Mesozoic eras, 95% of all species became extinct, likely caused by a massive eruptive event (likely the Siberian Traps, which is a large region of volcanic rock in Russia), type of eruption that produces flood basalts (the result of a giant volcanic eruption that covers large stretches of land or the ocean floor with basalt lava), 3 million cubic km of lava, covered the land of two Alaskas

question

What are some of the consequences of catastrophic volcanic eruptions?

answer

Release of lots of CO2 and SO2 into the atmosphere, greenhouse effect causes global warming, acid rain dissolves carbonates like the shells of microorganisms

question

What was the Cretaceous-Paleogene Mass Extinction?

answer

Fifth mass extinction, happened between the Mesozoic and the Cenozoic eras, also called the KT extinction (with K being Cretaceous and T being Tertiary somehow), 75% of all species died out, end of the dinosaurs, left a "KT" layer of iridium in rocks which was first found in Italy (separates Mesozoic and Cenozoic rocks, previously only typically found in extraterrestrial material), the amount of iridium found all over the world tells us the asteroid was at least 10 km in diameter

question

What would the effects of a giant asteroid impact such as the one in the Cretaceous-Paleogene extinction do?

answer

6 million times more explosive than the Mt. St. Helens eruption, tsunamis half a mile high, sun would be much less bright for years, flood basalts on the antipode, impact was likely in India

question

Can we have a Sixth Extinction?

answer

Yes, the Anthropocene event might be the uncontrolled population growth and resource consumption by an industrial species

question

What is Geobiology?

answer

Geobio focuses on the large-scale interfacing between the Earth systems and the biosphere

question

What is the Biosphere?

answer

The Earth system that includes all living organisms, not just plants and animals but also insects and bacteria, material and energy are always flowing in and out from other Earth systems so it is not static

question

What is an Ecosystem?

answer

What the biosphere is organized in, open systems of life and its surroundings (open here is a word which means the constant exchange between organisms and its environment)

question

What is the difference between an autotroph and a heterotroph?

answer

An autotroph generates its own food whereas heterotrophs eat autotrophs

question

What is metabolism?

answer

The chemical processes involved in the exchange of energy and nutrients (food) with the environment

question

How do autotrophs generate energy?

answer

Most commonly through photosynthesis which creates food from CO2 and sunlight, though when sunlight isn't available other reactions are possible

question

How do heterotrophs generate energy?

answer

Through respiration which is the breakdown of carbs into CO2 and energy

question

What is biogeochemistry?

answer

tracking a chemical through Earth's systems and interactions

question

What is the Phosphate Cycle?

answer

Phosphates are an essential nutrient for life to be formed (if a limiting nutrient is missing, then no new life is formed), rocks contain phosphates, this has to be found during the erosion process, can be carried by soil or by river, taken up by plants, animals eat the plants, animals release it back into the soil

question

What is a sink and what is a source?

answer

A source is where something is released to be used, a sink is where it's being taken in and fixed in place, interactions in biogeochemistry are defined as sources or sinks

question

What is the organic carbon cycle?

answer

Plants are eaten by animals and metabolized back to CO2, the burning of biomass yields CO2, the combustion of coal oil and gas yields CO2

question

What is the inorganic carbon cycle?

answer

CO2 dissolved in rain will form soluble bicarbonate, organisms use dissolved bicarbonate to make shells of calcite, shells accumulate to form limestone, subduction carries carbonate rocks into mantle (CO2 recycled in subduction related magmatism), continental collision causes metamorphism and melting in the crust, CO2 released and recycled back into the atmosphere

question

What is an extreme metabolism?

answer

A metabolism that does not depend directly on sunlight and photosynthesis (chemosynthesis), practiced by extremophiles

question

What are halophiles, acidophiles, and thermophiles?

answer

Halophiles survive in salt (like the Dead Sea), acidophiles survive in acid, and thermophiles survive in extreme temperatures (like hydrothermal vents at the bottom of the ocean, black smokers near mid-ocean ridges, and circulation of ocean water near hot magma)

question

How did life start?

answer

Conditions on Earth had to be just right (atmosphere rich in CO2, N2, and SO2, liquid water), the atmosphere was a "prebiotic soup" as experimented by Stanley Miller in the 50's who found it could create life

question

What are the origins of life?

answer

building blocks like NH3, HCN, amino acids and hydrocarbons, earliest organisms had self-replicating molecules like RNA and assembled in shallow water

question

What are the three domains of life and what makes composes them?

answer

Bacteria, archea, and eukarya make up the tree of life, bacteria and archea were only ever single-celled, eukarya is all multi-celled organisms, animals take up only one small branch

question

How did photosynthesis evolve?

answer

in a non-oxygenated atmosphere, perhaps around 3.5 ga, progressively modified earth's atmosphere, earliest preserved evidence of life is microbial mate (stromatolites)

question

What are stromatolite?

answer

ancient and modern, algal mats build up carbonate mounds in warm shallow seas such as Shark Bay, Australia, similar structures are found in rocks as old as 3500 ma

question

What was oxygen's relationship with early life?

answer

it was a poison and there were lots of anaerobic organisms, organisms developed methods to sequester oxygen, banded iron formations may be an example of this (reaction of oxygen with iron in seawater)

question

What was the great oxygenation event?

answer

photosynthesis continued and oxygen sinks became saturated which released oxygen into the ocean and atmosphere which likely killed many anaerobic organisms, which would later factor into the evolution of multi-celled organisms

question

What was the Cambrian Radiation?

answer

It was an evolutionary Big Bang around 540 mya, gave us organisms with hard body parts, huge increase in the diversity of species, also called the Cambrian Explosion

question

What was the Age of the Reptiles?

answer

Dinosaurs appearing at 240 MA and dominating for about 150 million years

question

When was the evolution of flowering plants?

answer

Radiation in the mid-Cretaceous

question

What was the Age of the Mammals?

answer

Mammals rapidly diversifying following the extinction of the dinosaurs

question

What did diversity of life look like over time?

answer

Not a straight shot up at all, varied up and down in number of species as life evolved and the earth changed

question

What are the types of extrusive rock?

answer

Low viscosity magma (basalt) like pahoehoe, aa, and pillow lava. High viscosity magma (andesite-rhyolite) like tuff (ash) and pyroclastic breccias

question

What is the difference between Aa and Pahoehoe lava?

answer

Aa is blocky lava and pahoehoe is ropy lava

question

What defines andesitic-rhyolitic lavas?

answer

Much more viscous than basaltic lava, flows much more slowly and the pressure can build much higher before it erupts, phreatic eruptions with volcanic ejecta and pyroclastic flows, like Mount St. Helens

question

What is welded tuff?

answer

Stronger than regular tuff (ash), ash particles still partly molten and soft when they were deposited so they flatten and become welded together

question

What are the types of volcanoes?

answer

Shield, volcanic dome, cinder-cone, stratovolcano, caldera

question

What defines a shield volcano?

answer

large, low angle, large broad shape, low-viscosity basaltic lava slides down and builds the volcano out over a very large area

question

What defines a volcanic dome?

answer

high viscosity rhyolite lava, building up the volcanic edifice over successive eruptions but builds up higher than a shield volcano because the lava flows slower so you get a diff shape

question

What defines a cinder cone?

answer

They call it a cone because the top of it looks chopped off, every time it erupts you have higher viscosity magma driving the volcano, gets up enough pressure to pop the top off of it, vent may be filled with volcanic debris

question

What defines a stratovolcano?

answer

Mount Shasta in North California, has distinctive strata or layers, pyroclastic, alternate between lava flows and pyroclastic layers with welded tuff and breccia, can be due to a volcano with medium viscosity lava, the explosive eruptions usually happen at the top whereas on the sides you have the lava flows

question

What defines a Caldera?

answer

A volcano that exploded so largely that there was no volcano left after, leaves a crater that usually fills with water, usually inactive but there may still be volcanic activity below, like Crater Lake, Oregon

question

What is a fissure eruption?

answer

More or less a dike that gets exposed at the surface, so it occurs in a line, which reflects the geometry of the dike, can sometimes be along a riff zone where you are pulling apart of seeing extension, material may get close to the surface and erupt

question

How does volcanism interact with the hydrosphere?

answer

They are a major heat source and drive thermal circulation of fluids through convection, as with geysers or geothermal springs

question

How does volcanism interact with the biosphere?

answer

It responsible for black smokers which is responsible for hydrothermal circulation near mid-ocean ridges, it is a source of life at the bottom of the ocean and contributes to ocean chemistry as much as all freshwater rivers

question

How does volcanism interact with the atmosphere?

answer

Volcanic ejecta (solids and gasses) go into the atmosphere and form aerosols (CO2 and SO2), which block sunlight, thus large volcanic eruptions can cause global cooling. For example Mt. Pinatubo in the Philippines lowered global temp by 1 degree for 15 months.

question

Where are volcanoes?

answer

Anywhere plate tectonics are

question

What is the difference between hazard and risk?

answer

Hazard is something that can cause harm, risk is the CHANCE that the hazard will cause someone harm

question

What are some volcanic hazards?

answer

Lava flows, ash falls, pyroclastic flows, lahars (the most dangerous - volcanic mud flow), volcanic gases, tsunamis

question

What are pyroclasts?

answer

Chunks of magma/lava and the lid (host rock) of the volcano that are part of the explosion

question

What is a pyroclastic flow?

answer

Hot ash, gases, and pyroclasts rolling downhill, because everything is hot and buoyant there is very little resistive friction so they flow VERY fast (>60 mph), an ex. is Mt. Pinatubo in 1991, flows are produced by a lateral blast from a side vent or the collapse of a vertical ash cloud erupting from a central vent

question

What are lahars?

answer

The most dangerous of the volcanic hazards, like a pyroclastic flow but wet, can occur when a pyroclastic flow hits a river/snow/ice

question

What effect can volcanic gasses have on the environment?

answer

Mass amounts of CO2 can kill vegetation around the area, such as the tree kill area near Mammoth Mountain, CA near a caldera

question

How can tsunamis occur from volcanoes?

answer

During the eruption there is lots of mass in movement, if next to a body of water this can cause a tsunami, as seen in Krakatoa

question

What volcanic hazard kills the highest number of people?

answer

Pyroclastic flows

question

How did they know that Mt. St. Helens was going to blow? What was the complication?

answer

There was a physical bulge outward at the top of the volcano, an earthquake triggered a landslide, which caused the volcano to laterally blast even though they thought it was going to be a central blast, launching pyroclastic flow into Yakima

question

How can we reduce volcanic risk?

answer

Don't live near them. Also, understand the dynamics of volcanic hazards so we can mitigate risk (such as not building in likely lahar pathways), also geophysical monitoring of volcanoes to take the pulse of the volcano (this worked in the Mt. Pinatubo eruption and they were able to evacuate tens of thousands of people)

question

How can we harness volcano's heat?

answer

Through geothermal heating. Heat is transferred by circulating water that is heated underground (like with hot water radiators)

question

What is geothermal power?

answer

If water is hot enough it can drive steam turbines and generate electricity, the geysers geothermal power plant north of SF generates 600 megawatts of electricity, as much power as a nuclear power plant

question

What do you do during an earthquake?

answer

Drop, cover, hold on

question

What is the big unsolved question of earthquakes?

answer

can they be predicted

question

What are the basic properties of earthquakes?

answer

Location of faulting (origin time, epicenter, and focal depth), type of faulting (normal, reverse, or strike-slip), size of faulting (magnitude), intensity of shaking (dependence on fault properties and distance from fault), secondary effects (tsunamis and landslides and liquefaction)

question

What are the three types of plate boundaries?

answer

Transform fault (lateral motion - strike slip), spreading center (divergent motion - sea floor spreading), subduction zone (convergent motion)

question

What is normal faulting?

answer

Caused by tensional forces, hanging wall moves downward, footwall moves upward (footwall is the one you can walk up)

question

What is a reverse fault?

answer

A thrust fault, compressional, hanging wall moves up and foot wall moves down, shallow dipping plane (less than 45 degrees)

question

What is a strike-slip fault?

answer

Moves laterally left or right (whichever is moving towards you is how you know), caused by horizontal shearing, characterized by offsets in geographical features like rivers and streams, dated through radioactive dating of sedimentary rock

question

What causes earthquakes?

answer

A sudden slip (movement) on a fault that has reached its breaking strength

question

What is elastic rebound theory?

answer

Stress builds up along faults and when you let go it will snap off, earthquakes happen when this snap happens and releases all the stress that it has built up, the points when it snaps are the high points on the graph, in between is the recurrence interval (this is because the amount of stress released varies can be impacted by earthquakes nearby, mining, etc.), rock and wooden fence example

question

How do foreshocks and aftershocks interact with earthquakes?

answer

Before the earthquake foreshocks may act as warnings, but they can also happen a lot and then not have an earthquake so they are not a reliable predictor. Then there is a slip along the fault that is the actual earthquake. Then after things are displaced and that causes aftershocks which are lots of little earthquakes induced because of the slip, decreases with time (dependent upon the magnitude as to how long they will last)

question

How do we measure earthquakes?

answer

used to seismograph, which is created by attaching a ball with a pencil to a spring on a piece of metal and letting it scribble as it shakes (with a downstroke indicating that the earth moved up and vice versa), come in both vertical and horizontal (this tells us how the Earth moved in more of a 3D model), we don't really use this way anymore and instead use electromagnets that masure the magnetic field and the amount of electricity generated when they move

question

What are the types of body waves?

answer

P waves and S waves

question

What is a P Wave?

answer

Primary wave, moves faster, smaller than the S wave, compressional, travels faster in rocks that are very hard and less compressible

question

What is a S Wave?

answer

Secondary/Shear wave, arrives later, smaller than the surface waves, travels faster where the resistance to shear is greater (in harder rocks), oscillates up and down not in the direction that it is traveling

question

What are surface waves? What are the types?

answer

They travel across the surface of the Earth and arrive quite a bit later, larger than both P and S waves and faster, surface waves are destructive, speed depends upon rock properties about one wavelength beneath the surface, exist because of the interaction of air with hard rock, there are Rayleigh waves and Love waves

question

What are Rayleigh and Love waves?

answer

Surface wave, elliptical motion just like a wave, sorta like a P wave and an S wave in the nature of their motion, Love waves are side-to-side motions, these happen at the same time

question

How do you locate an earthquake?

answer

You measure the arrival times of the P and S wave and then use a travel-time difference to estimate distance from epicenter to station, triangulate to find epicenter

question

What is the difference between intensity and magnitude? What do they measure?

answer

They measure earthquake size. Intensity measures the ground shaking on the Mercalli scale and magnitude measures the size of the rupture on a fault, intensity is subjective bc it depends on the person reporting the shaking whereas magnitude is objective and all observations of one earthquake point to a unique magnitude

question

What is an isoseismal?

answer

Lines on a map showing where an earthquake was experienced and with what intensity

question

If you increase an earthquake's magnitude by 1, will everything else increase proportionally?

answer

NO, earthquake magnitude is NOT linear, it's logarithmic

question

What are some examples of seismic hazards?

answer

Primary hazards include surface faulting and ground shaking, secondary hazards include landslides, liquefaction, tsunamis, and fire

question

How is seismic hazard measured?

answer

By maximum intensity of shaking expected over the long term. Can be plotted on a map.

question

How is seismic risk measured?

answer

By the loss of lives and property expected over the long term The problem of seismic risk is described on the slide as risk = probable loss (lives and dollars) = hazard x exposure x fragility ÷ resiliency

question

How are tsunamis generated?

answer

Uplift of the seafloor during thrust faulting produces a surge of water that moves outward as a long sea wave, a tsunami is only a few centimeters high in the deep ocean but can increase to many meters high close to shore

question

Carbon is stored in the form of carbonate in pelagic clays. This is an example of a:

answer

Sink in the carbon cycle

question

Warming of the global climate system would:

answer

Increase the rate of evaporation in the ocean

question

If there was an increase to the rate of evaporation in the ocean, what would happen?

answer

Produce more clouds from water vapor

question

If more clouds were produced by water vapor what would happen?

answer

It would lower the heat received from the sun

question

Global warming increasing the rate of evaporation in the ocean, leading to more clouds, leading to lower heat is an example of what?

answer

A negative feedback loop

question

How can we explore the Earth's deep interior?

answer

Direct sampling in boreholes and mines, samples brought to the surface by tectonics, deeply eroded ancient mountain belts, constraints on chemical composition from meteorites, seismic imaging (tomography), lab experiments on rocks at high pressures and temps, observations of Earth's gravity field (geoid), observations of Earth's magnetic field

question

What is Earth's chemical layering?

answer

Layering of dense materials of different compositions throughout the Earth. Crust and mantle are very similar, and outer and inner core are quite similar, but they are vastly different from each other. Jumps from mostly oxygen to mostly iron

question

How does the earth cool?

answer

Conduction (dominates in the lithosphere and other thermal boundary layers) and convection (dominates throughout convecting mantle and core with the core convecting as a liquid and the mantle convecting as a solid). Convection is much more efficient than conduction in transporting heat.

question

What are the melting curve and geotherm?

answer

Small change in temperature within depth. On the other side of the melting curve, materials are liquid. On the other side of the geotherm, they are solid.

question

How does heat flow while conducting compare to heat flow while convecting?

answer

Cools much, much more slowly due to it being inefficient. It takes 200 years to cool a layer 100 m thick, so if a square was 100 Km thick it would take 1 million years to cool

question

What is the thermal structure of the oceanic lithosphere?

answer

Conductive cooling occurs through oceanic lithosphere that thickens as the square root of its age, the depth to the seafloor is proportional to lithospheric thickness according to the principle of isostasy, therefore depth increases as the square root of age

question

What is seismic imaging?

answer

The best constraints that we have of the deep Earth, measured through propagation of body waves and surface waves, P wave and an S wave travel through the body of the Earth (I'm confused on this so double check this with the book or another source)

question

What is a shadow zone?

answer

A place in which the P or S wave does not reach as it travels outward through the Earth from the epicenter. S Waves are like a snake and based on shearing material so they do not travel through the liquid outer core. P waves shadow zone laterally, they move in a web and then straight lines going through the Earth, they move like a slinky and _can_ travel to the other side because liquid can be compressed.

question

What is the structure of Earth's Deep Interior?

answer

It has a radial structure (crust, lithosphere, asthenosphere, mantle, outer core, inner core). 3 Basic parameters: P wave speed, S wave speed, and density

question

What are the components of earth's deep interior?

answer

Solid crust and mantle (silicate rocks, solid-state convection causes plate tectonics), sharp core-mantle boundary (2900 km in depth, decrease in seismic velocity, increase in density), liquid outer core (conducting iron-nickle alloy, convection creates geodynamo system), solid inner core (1250 km radius)

question

What is seismic tomography?

answer

The construction of 3D images of the Earth's interior from seismograph stations that record waves from many earthquakes. These measurements give you an idea of how fast the wave is traveling, and you can map from there (for example, if it arrives early, you know it went through a dense, cold spot on the Earth). You can figure this out based on average speed and stations around you as well as the average global viscosity model for the Earth (which says at any given point how fast you can expect things to travel in what part of the Earth). You can also build tomographic maps this way of the mantle because the waves act as a CT scan. The deeper you go the more the map changes.

question

What is the structure of the upper mantle?

answer

Lithosphere (crust, uppermost mantle with high seismic velocities), the asthenosphere (low-velocity zone), solid-solid phase changes occur (which we can prove by taking material exhumed through tectonics and we put it under very high pressure and we compress it on a tip, if its from the asthenosphere it should turn from one mineral into another with much tighter packing between atoms, if you kept the pressure on it should turn into an even denser material)

question

What are the two type of mantle convection?

answer

Whole mantle and stratified convection. In stratified they are different cells and there is little connection between the two convections, seems to be a theory

question

What is the geoid?

answer

Earth's surface perpendicular to gravitational force, defines sea level and the shape of Earth, can be mapped by satellites, constrains mass distribution inside the mantle (consistent with seismic tomography)

question

What are some properties of Earth's magnetic field?

answer

At the surface it looks like a simple dipole (two pole) magnet but true north is actually off by 11.5 degrees, magnetic poles wander as the field changes, generated by geodynamo in the liquid iron outer core, direction of the poles spontaneously flips at irregular intervals (gets weaker before it flips)

question

How can magnetic mapping measure help date seafloor spreading and volcanoes?

answer

Assuming there is a more or less constant rate of sea floor spreading, if you measure how positive or negative the polarity is you can get an idea of time. Then you can make a map of all the polarities. You can match this polarity map against a core drilled from a volcano, and it gives you a way to date the volcano.

question

What is the geomagnetic time scale?

answer

A timeline arranged by the polarity of Earth at that time, organized into chrons and subchrons

question

What is thermoremanent magnetization?

answer

It was the first example of people realizing that you could capture magnetic fields from the past. They would heat up the rocks enough that the magnetic field was no longer stable, and when the rock cooled back down it captured the new magnetic field of the time of the fire. So now if we saw the rocks we would know when the fire was

question

What is depositional remanent magnetization?

answer

Some sediment falling to the bottom of the river has magnetic minerals, when the particles are falling they will align with the magnetic field, when it turns to sedimentary rock it will capture that alignment

question

What is magnetic stratigraphy?

answer

This is a little unclear, but I believe it is the mapping of the polarization of volcanic or sedimentary rock into chrons over large timescales (like eons)

question

How is the Earth's actual magnetic field different than the model expected?

answer

Instead of the south pole being in Antartica, it's right under Australia. There are also anomalies in the shape.

question

What happens when looking at the magnetic field of the core-mantle boundary over time?

answer

Secular variation. Some changes but not a lot. This makes sense because convection in the outer core is not in a steady state and is moving, thus the heat driving the magnetic field isn't stable, thus the magnetic field isn't stable.

question

What are surface processes controlled by?

answer

Interactions of the atmosphere and hydrosphere with the lithosphere Physical and chemical interactions, redistribution of material, and creation of landscapes

question

What is the sedimentary rock cycle?

answer

Weathering, erosion, sediment transport, sedimentation (deposition), lithification

question

What are the two kinds of weathering?

answer

Weathering is the breakdown and fragmentation of solid rock by surface processes. There is chemical weathering and physical weathering.

question

What are the properties of chemical weathering?

answer

Action of water (silicates in water producing clay), action of oxygen (oxidation of sulfides produces sulfuric acid), action of CO2 (dissolution of carbonate rocks), dissolution of rocks by organic and inorganic acids in soil

question

What are some of the products of chemical weathering?

answer

Rock and mineral fragments (detritus), clay, iron oxides/hydroxides, dissolved solids

question

What is wedging?

answer

A type of physical weathering that can occur in frost, roots, or along joints. It is when something (water, roots, other rock material) work their way through a solid rock and breaks it apart

question

What is thermal exfoliation?

answer

Type of physical weathering. It is when the outer shell heats up and cools down more than the inner part of it, so it sheds the outer layer in a large sheet of rock all at once

question

What is soil?

answer

A product of weathering. Starts with bedrock which gets gradually broken up, then things are grown on top of it and roots break it up, too, also contributes to weathering itself by containing chemicals and growing things that break other things down. Topsoil holds water and generates humic acids, calcium aluminum or iron oxides may be precipitated in subsoil.

question

What is talus?

answer

Product of physical weathering. Wedging, wind, water.

question

What is the difference between weathering and erosion?

answer

Weathering is the breaking down of products, erosion is the removal of the products from the surface.

question

What are some agents of erosion?

answer

gravity (mass wasting), wind (main driver in deserts), running water (canyons), waves, glaciers (scrape as they go by and carry things with them, leave scars on the bedrock)

question

What controls weathering?

answer

duration (longer), parent rock (the more stable the mineral the less weathering), temp (the hotter the climate the less physical weathering and more chemical weathering), precipitation (the more the more weathering), acidity (the more the more chemical weathering), topography (the steeper the slope the less chemical weathering and more erosion)

question

How does CO2 in the atmosphere contribute to weathering in the form of a negative feedback loop?

answer

Reduced weathering rate, increase in CO2, climate warming and increased weathering, weathering reduces CO2 in atmosphere, lowered CO2 cools, lower temps and lower CO2 leads to reduced weathering

question

What is mass wasting?

answer

Large-scale motion of rock or soil down slopes under gravity.

question

What characterizes mass wasting?

answer

Velocity (how fast material is moving), runout (how far material travels), and water content

question

What is a rock fall?

answer

A free fall of rock at very high velocity, low runout

question

What is a rock avalanche?

answer

Air mixed in with the flow of materials and more or less a dust cloud flowing down hill, high velocity and high runout, can be caused by an earthquake

question

What is a rock slide?

answer

Low run out, not in free fall and will more or less stay together, can be caused by wedging

question

What is soil creep?

answer

Movement over long time scales, gradual down slope motion of soil under gravity, if you build a house on it it will move, soil on the surface moves faster than soil below it due to amount of pressure

question

What is slump?

answer

Slow slide of water saturated soil. Not big chunks of rock. Can happen suddenly as an event.

question

What is a debris flow?

answer

Rapid flow of rock fragments in a muddy matrix. Rock flow plus water and mud. More material than water.

question

What is a mud flow?

answer

Much more water than material. Unconsolidated sediment that can flood. High velocity high run out. Can be triggered by an earthquake. A lahar is a type of mud flow so it can also be triggered by a volcano. Can also be triggered by rain.

question

What is a debris slide?

answer

o Talus and soil slide down the side of a steep valley o Talus is chunks of rock you get from weathering o High velocity high run out

question

What is the difference between flow, avalanche, and slide?

answer

Flow is with water, avalanche is with air, slide is with neither

question

What influences mass wasting?

answer

Type of material on the slope, amount of water in materials, angle of slope, instability of slope

question

What initiates landslides?

answer

Natural undercutting by rivers or waves, slope denudation by fire or clear cutting, excavation by man for roads, heavy rain or snow, freeze-thaw cycles, earthquakes, volcanoes

question

What is the role of water in slope failure?

answer

Adds weight, lubricates slip surfaces, weakens clay horizons, raises pore pressure and reduces friction

question

WHAT R WE GONNA DO ON THIS TEST?

answer

PASS

USC Geology 105 Midterm 2 Spring 2018 – Flashcards

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