Green Cards Flashcards
earthquake
sudden release of stored energy because of a slippage along the fault in earths crust
big bang
splattered radiation where particles formed to form the galaxy aka Earth (E = mass x speed of light)
biosphere
the ecosystems and biology in atmosphere, hydrosphere and geosphere
baymouth bar
a sand bar that completely crosses a bay, sealing it off from the open ocean
seawalls
Protects shoreline from breaking waves
Primary waves
push-pull motion that changes the volume of the intervening material. Travels through solids, liquids and gases
Secondary waves
shear motion at right angles to their direction of travel. Travels only through solids
whats the deepest below the earths crust
reached by Hamn was 12.3k in the earths crust
Whats the MMI scale used for
used to describe the earthquakes intensity
richter magnitude
measures the amplitude height of the largest recorded wave at a specific distance from the seismic source
Intensity
semi quantitative measure of the observed effects of an earthquake on the natural and human built environment
epicenter
the point where circles of epicentral distance intersect
what formed seafloor spreading
formed concepts of plate tectonics
where are the oldest ridges found
by the edges of the continents
where are the youngest ridges found
along the crest mid ocean ridges
name of Wegners continental drift
PANGEA
seafloor spreading
formation of new areas of oceanic crust. Occurs through the upwelling of magma at mid ocean ridges
water particle motion & wave base
-the molecules that move in circular motion (water particle motion)
-the circular motion disappears once it gets deep (wave base line)
wave height
vertical distance between trough and crest
wave length
horizontal distance between wave crests
shorelines
erosional and depositional processes combine along coasts to create landscapes that undergo rapid change
Spit
elongated ridge of sand that projects from land into the mouth of an adjacent bay
Rayleigh waves and love waves
- move the surface of the earth around in a circle, forward and down then back and up (rayleigh)
-shake the surface side to side (love)
convection
hot mantle rock rises, cools, sinks and drags plates along
S waves minute difference
5 minutes
3 types of plate boundaries
Divergent, Convergent and Transform plate boundaries
Divergent plate boundaries
two plates moving away from each other (new oceanic mantle is formed)
Convergent plate boundaries
two plates approaching each other (mantle is consumed)
Transform plate boundaries
two plates move alongside one another (nothing changes)
ridge push
plates slide down the flank of mid ocean ridges under the downward push of gravity
slab pull
the dense, leading edge of a plate pulls the rest of the plate down into the mantle
earthquake impacts
-surface rupture
-shaking leading to buildings falling and fires
-subsidence
-tsunami waves
Tsunami
tsu=harbour
nami=wave
results from a vertical displacement along the fault located on the ocean floor, a large undersea landslide triggered by an earthquake
Tides
repetitive daily changes in the elevation of the ocean surface due to gravitational attract
notion of mantle convection
if crust is consumed by the mantle in some places and extruded in others, there is a form of cycling within the mantle itself
negatives of groins
sand erodes on the down current side
Lower intensity =
felt observations
Higher intensity=
damage observations
Wave cut cliffs
where erosion dominates over deposition, some distinctive features can be formed by the erosive power of waves
how old is the oldest oceanic crust
4 billion years old
A-P-S time travel graph
the time elapsed between the first arrivals of p and s waves. Can be scaled to an equivalent distance from the recording station and the earthquake epicenter
Isostasy
the equillibrium that exists between parts of the earths crust
How are ocean basins formed in the first place
-heat builds up under the continent
-continental litoshpere warps upward and thins
-Astenosphere rock wells up and melts
-Mafic magma rises to produce oceanic crust in rift valley
Triple junctions
a point where the boundaries of three tectonic plates meet
whats the upper and lower part of the crust made of
upper crust = basalt
lower crust = gabbro
what are some consequences of plate tectonics
-mud deposited offshore
-sand occurs close to shoreline
-classic sediments are derived from wearing down of mountains that owe their existence to the convergence of plates
Foreshore
lower wet part of the beach
backshore
upper part of the beach
as tides rise what happens
flood currents
wind generated waves
provides most of the energy that shapes and modifies shorelines
wave period
the time it takes for two successive waves/crests to pass a given point
when do waves feel bottom
at a water depth equal to half their wave length
which way do sand particles move
zig zag pattern (5-10m per day)
whats a plate tectonic
a rigid slab that connects with other rigid slabs that comprise earths rocky shell
mid ocean ridge
magnetic polarity of magnetite crystals within the ocean floor
magnitude
quantitative measure of the amount of energy released during an earthquake based on seismic wave characteristics
mantle convection
the movement of the mantle as it transfers heat from white-hot core to the brittle lithosphere. The mantle is heated below and cooled from above
atmosphere
the envelope of gases surrounding the earth or another planet
hydrosphere
the water on earth, the planet, underground and in the air
renewable energy sources
-hydroelectric power
-wind energy
-tidal energy
-wave energy
-solar energy
-geothermal energy
geosphere
the rocks and minerals on earth, the solid parts on earth
barrier islands
built up sediment that are separated from mainland by a lagoon
beach nourishment
adding sand to a beach
Inertia
a bulge in the ocean. Develops on both sides of the earth
earthquake intensity is measured by?
measured by the observed effects to natural environments and human built environments
Swash
the sheet of water that moves up the beach after the wave breaks
backwash over swash =
distructive
swash over backwash =
constructive
waves in shallow water
the closer the waves get to shore the smaller the wavelength gets and the higher the wave height will become
how much energy is derived from non renewable
80% worlds energy derived
geothermal energy
-uses natural heat of the earth
-commercial scale systems centred on volcanically active areas
-heat to produce steam to turn turbines to generate electricity
FWWB
fair weather wave base = the maximum water depth affected by normal day to day
Photovaltic cells
silicon conductors convert sunlight to electricity
long term effects
carbon dioxide emissions (greenhouse effect, global warming)
Green house effects
solar radiation reflected from surface some absorbed
Shoreface
mostly sand swept away by fairweather waves
SWB
storm wave base = water depth affected by storm waves
Tidal deltas
-gaps in barrier/island systems that are produced by tidal channels
-allows water to pass back and forth during rising and falling tides
Longshore currents
easily move the fine suspended sand and roll larger sand and gravel along the bottom
