GEOL120 Final

exponential growth

a constant percentage added at each time interval vs a constant number

N=No\*e^kt

sustainability

sustainable development is economically viable, environmentally benign, socially just, and ensures future generations will have equal access to Earth’s resources

freshwater salinization

road salts going into the drinking water supply

nitrogen pollution

fertilizers cause an excess of nitrogen, which is a limiting factor of growth

residence times

a measure of the time it takes for the total stock or supply of the material to be cycled through a system

mass balance approaches

makes it possible to track the amount and sustainability characteristics of circular and/or bio-based content in the value chain and attribute it based on verifiable bookkeeping

pools

deep areas produced by scour, or erosion at high flow, and characterized at low flow by relatively deep, slow movement of water

fluxes

rate of transfer

steady state

a system in which the input is approximately equal to the output, rough equilibrium is established

earth system science

the study of the entire planet as a system in terms of its components; asks how component systems such as the atmosphere, hydrosphere, biosphere, and lithosphere are linked and have formed, evolved, and been maintained

uniformitarianism

“the present is the key to the past”; processes similar in the past, but with different magnitude or frequency

catastrophism

rapid changes linked to large events; local, regional, or planetary scale

Geosphere/lithosphere, atmosphere, hydrosphere, cryosphere, biosphere

what are the 5 spheres of Earth?

consequences of the nitrogen cycle

human activities like the burning of fossil fuels, deforestation, and making fertilizers pollute the air, soil, and water by increasing greenhouse gas emissions and impact biodiversity and ecosystem functioning

scientific method

1. Observation of a phenomenon
2. Development of a hypothesis to explain the observations
3. Testing the hypothesis using carefully considered experiments
4. Evaluating whether the hypothesis remains valid after testing, developing better tests, & modifying the hypothesis as required
5. A hypothesis that passes repeated testing is regarded as theory

it increases the impact on limited resources

why is population growth an environmental problem?

Wegener’s theory of continental drift

he said that the continents looked like puzzle pieces that could fit together, but he didn’t have a mechanism for how this could happen so he was discredited by the scientific community; he believed that the continents were floating and were pushing through the mantle and that mountain belts were on continental edges

seafloor spreading

Hess said that hot material rises at oceanic ridges and leads to high heat flow, volcanic activity, and ocean floor bulging up at the ridges; ocean crust returns to the mantle at the same rate in trenches; combines continental drift with mechanism of convection

we can use seismographs to examine the paths and speeds of seismic waves that travel through the Earth’s interior

how can we use seismology to learn about the internal structure of the Earth?

divergent, convergent, transform

what are the basic types of plate boundaries?

isostasy

the principles whereby thicker, more buoyant crust stands topographically higher than crust that is thinner and denser; the rocks which mountains are formed of are less dense than the rocks of the mantle beneath, so they float

magnetic stripes

the magnetic field is captured in cooling lava; oceanic crust records the changes in the magnetic field; these features are perfectly symmetrical and sit across the ridge axis

subduction zones

when 2 plate boundaries converge and one plate subducts beneath the less dense one; oceanic crust will ALWAYS subduct beneath the continental crust

mid-oceanic ridges

formed from divergent plate boundaries; oceanic plates are generated here; magma is focused at the axis of spreading ridges

hot spots

a place where hot mantle material rises in a stationary and semi-permanent plume, and affects the overlying crust, found far away from plate boundaries

characteristics of Earth’s internal structure

inner core (solid), outer core (liquid), mantle, crust, asthenosphere, lithosphere, crust

p-waves

push-pull wave, like a sound wave; fastest wave and arrives first to the seismograph; body wave travels through Earth’s interior and all media

s-waves

secondary or shear waves; slower waves that can travels through earth’s interior, but not liquid layers; shadow of these waves defines the diameter of the outer core

minerals

solid materials making up rocks

isotopes

atoms of the same element with a varied number of neutrons

atoms

the smallest part of a chemical element that can react or combine with another element; structure dictates their microscopic and macroscopic properties and how they bond dictates what we see in the many minerals in nature

chemical bonding

types include: ionic (a bond formed when electrons are transferred from one atoms to another), covalent (the sharing of electrons between atoms, strongest bond), metallic, van der waals

intrusive igneous rocks

when igneous rocks are crystallized from magma beneath the ground; results in larger crystals

extrusive igneous rocks

when igneous rocks are cooled from erupted lava or pyroclastics; results in small crystals

metamorphic rocks

heat, pressure, and chemically active fluids change mineralogy and the texture of pre-existing rocks; non-foliated: crystallizes into larger grains; foliated: minerals align and form rock cleavage (parallel, layered, banded)

igneous rocks

dictated by the rates of magma cooling, beneath the surface = slower, near/at the surface = faster; slower cooling = coarser mineral particles

sedimentary rocks

are transported, deposited, and lithified; results in either detrital (broken fragments cemented together) or chemical rocks (formed from material from organic or inorganic chemical precipitation)

law of original horizontality, law of superposition, law of crosscutting relationships

what are the major rock laws?

acid mine drainage

water with a high concentration of sulfuric acid that drains from coal mining areas, causing surface water and groundwater pollution; produced by microbial and geochemical reactions when sulfide minerals associated with a coal or metal come into contact with oxygen-rich water near the surface

produces primary igneous rocks

how does volcanism affect rocks?

weathering

turns igneous and metamorphic rocks into sedimentary rocks; the breaking apart or chemical decomposition of material at or near the surface

stable isotopes

isotopes that don’t decay

radio isotopes

unstable isotopes that undergo nuclear decay at a constant rate; can be used to date when the rock was crystallized

solid, inorganic, naturally occurring, chemically defined, crystalline

properties of a mineral

rock

aggregates of one or more minerals, naturally occurring crystalline substances with defined properties

rock cycle

It involves three main types: igneous, sedimentary, and metamorphic. Igneous rocks are formed from the cooling and solidification of magma or lava. Sedimentary rocks are formed from the accumulation and cementation of sediment. Metamorphic rocks are formed from the alteration of existing rocks due to heat and pressure.

subduction

recycles sedimentary and metamorphic rocks back into the mantle, generating new igneous rocks

rock-forming mineral groups

silicates, halides, carbonates, oxides, sulfides, native elements

ways to identify minerals

color, streak, hardness, luster, specific gravity. cleavage, crystal habit, special features

chemical weathering

the dissolution of material by chemical reactions; usually acids

physical weathering

breaks into smaller pieces with no chemical change; microbes, animals, trees

species

individuals capable of interbreeding

communities

populations of different species living in the same areas

ecosystems

communities of organisms and its nonliving environment in which chemical elements cycle and energy flows

keystone species

species that have a strong community effect, with an influence disproportionate to their abundance

climax communities

a community of plants, animals, etc that have reached a steady state because of ecological succession

it’s important for all aspects of life (plants, animals, humans)

why is biodiversity important?

indigenous species

species found in the area where they evolved

exotic species

species brought into an area/region by humans purposely or accidentally

invasive species

exotic species compete with indigenous species, may displace the indigenous species

ecological niches

the role an organism plays in its community

riparian zone

critical interface between soil and stream; demonstrates the ability to prevent pollutant movement from upland land uses into stream and coastal waters; most work on removal of groundwater nitrate in agricultural watersheds; stream restoration: riparian reconnection leads to increased denitrification and improved water quality

controlling biodiversity

habitat loss, invasive species, overexploitation, pollution, climate change associated with global warming

wetlands

the presence of water at the surface or root zone, unique soil conditions, vegetation adapted to wet conditions

stream and river restoration

filling the stream with rocks to slow the flow, planting vegetation on the banks of the stream

denitrification

a key component of the water quality maintenance function of riparian zones; anaerobic and heterotrophic

threats to biodiversity

limited number of habitats and ecological niches, pollution and stresses restrict the flow of energy and nutrients, fragmentation by land use transformation, intrusion of invasive exotic species, habitat simplification or migration barriers

catastrophes

a large amount of damage and life; damages to people, property, or society are sufficient that recovery or rehabilitation is a long involved process

climate change and risks of natural hazards

increases the possibility for more droughts and intense storms; more heat in the atmosphere and warmer ocean temps can lead to increased wind seeds in tropical storms

magnitude

intensity of a natural hazard in terms of the amount of energy released

frequency

recurrence interval of a disastrous event

how to mitigate risks from flooding and climate change

increase stormwater management features, protect floodplains, anticipate “perceive, avoid, adjust”

how risk is determined

the probability of an event x consequences

forecasting

includes range of certainty

prediction

specifying date, time, and size

relationship between population growth and natural hazard risks

positive relationship; pop increase leads to greater loss due to natural hazards

cause of Hurricane Katrina

loss of wetlands. levees broke, regional subsidence faster than appreciated, geographic location played a role (Mississippi and Lake Pontchartrain)

inverse relationship

magnitude and frequency have a _______

mercalli scale

the intensity of an earthquake is measured using observations made by people who felt the earthquake, rather than direct measurements of the earthquakes seismic waves

moment magnitude

calculated by measuring the seismic moment, which is the product of the average amount of slip on the fault, the area of the fault that slipped, and the rigidity of the rock (logarithmic); based on the area of the fault, velocity of rupture, and the strength of the rocks

Richter scale

a measure of the amplitude of seismic waves generated by an earthquake (logarithmic); based on the amplitude of the largest seismic wave

magnitude is amplitude of the largest wave and intensity changes depending on where you’re measuring the earthquake

earthquake magnitude vs intensity

active fault

a fault active within the past 10,000 years

strike slip faults

motion of faults parallel to the strike of the fault; most associated with transform boundaries

dip slip faults

most of the motion confined along the fault plane

reverse fault

block above fault moves up relative to block below the fault (up-dip) common in mountain building

normal fault

block above fault moves down relative to block below the fault (down-dip); common in subduction zones like Japan

focus

the point beneath the Earth’s surface where the seismic energy is released

epicenter

the point of Earth’s surface directly above the focus

p-wave, s-wave, r-wave

types of waves produced by earthquakes

intensity = mercalli scale, magnitude = Richter and moment magnitude scale

how are earthquake intensity and magnitude measured?

based on the observations of people who experienced the earthquake and is measured by the Mercalli scale

how is earthquake intensity characterized?

r-wave

earthquake wave that travels by rolling motion of the ground, slower than the other waves; are the most damaging since they occur on the surface

wind velocity, duration, fetch

what influences wave height?

pushes back the coastline because of sand supply, severe storms, rise in sea level, and human interference

how does erosion shape coastlines?

we can make artificial barriers to attempt to reduce beach erosion

how do we manage coastal erosion and restore coastlines

why coastal areas are at risk for natural hazards

more prone to natural disasters like tsunamis, hurricanes, and flooding

beach nourishment

an artificial barrier that is created to pump sand onto the beach but can be very expensive

jetties

an artificial barrier that is paired at the mouth of an inlet, designed to stabilize the channel, protect the beach from waves, and minimize deposition in channel

groins

an artificial barrier created to deplete the updrift beach of sand, usually in groups perpendicular to the beach