Questions Flashcards
How old is the Earth?
4.6 billion years
The Milky Way contains?
Sun, Earth, planets, hydrogen gas
Most abundant material
hydrogen gas
Elements up to Fe formed
nuclear fusion
Is the earths atmosphere similar to the first?
no
According to condensational sequence hypothesis, the elements that condensed last were
volatiles
the primary source of earth’s early hydrosphere
comet, asteroid, meteorite
moon was formed by
another satellite
most abundant material on Earth
mantle
most abundant gas on Earth
Nitrogen
Magma ocean formed on Earth
early in history
percentage of Earth covered in land
30
Echo sounding is important tool for understanding
the bathymetry of the ocean floor
Primary waves differ from secondary waves (seismic)
it travels through solid and liquid
Gravimeter is an instrument designed to
measure density
Which hemisphere contains the greatest proportion of ocean surface
southern
submarine canyons most likely formed by
turbidity currents
‘the present is the key to the past’ is the principle of
uniformitarianism
Where are MORBS created
along mid-ocean ridges
OIBs such as Hawaii are formed by
mantle plumes
abyssal hills are
blocks of faulted oceanic crust
a transform fault is a tectonic boundary where
plates move horizontally past each other
Mid ocean ridges rise above the adjacent seafloor because it is
Hotter than the adjacent seafloor, supported by upwelling asthenosphere, site of lava eruption and deposition
Which of Earth’s layers is lightest?
continental crust
The Wilson cycle refers to
rifting and assembly of continents and opening and closure of ocean basins
The shallowest part of the continental margin is
shelf
The climax of the last ice age was
18000 years
The Earth’s oldest rocks are found at the ____ of continents
interiors
Pangea was
The one supercontinent was existed 200 million years ago
The deep ocean basin contains
trenches, abyssal plains and oceanic ridges
All plate boundaries are characterised by
narrow belts of earthquakes
magnetic stripes or patterns on the seafloor are
caused by reversals of the Earth’s magnetic field
The age of oceanic crust can be determined from by
marine fossil
magnetic anomaly
Is the East pacific rise part of the pacific ring of fire?
no
The East African rift system represents a _____ plate boundary
divergent
the Andean volcanoes in South America are products of
plate subduction
oceanic lithosphere is younger than continental lithosphere because
plate subduction
faster spreading ocean ridges are
shallower and smoother
the two main types of sediments are
clastics and non-clastics
the formation of atolls is an illustration of
seafloor spreading
oceanic crust becoming denser with age
oceanic volcanoes becoming inactive
a normally graded pile of sediments
fine at the top and coarse at the btttom
terrigenous sediments come from
land
marine sediments on the ocean floor are less than 180 millions years odl because of
plate tectonics
The most widespread type of marine sediment is
biogenous
the term for all physical and chemical processes that transform sediments into rocks is
diagenesis
examples of hydrogenous sediments are
manganese and phosphorite nodules
the most dominant type of sediment in the neritic environment is
terrigenous
greatest volume of marine sediments is located in
continental rises
carbonate sediments are rare in deep-sea sediments because
carbonate shells dissolve in deep water
despite the fact that the equator receives more sun heat than higher latitudes, it is not steadily increasing in temperature primarily because
poleward heat transport by the ocean and the atmosphere
compared to the atmosphere, the ocean can hold
more heat
thermocline is a
region of sharp temperature change between upper and deep ocean
the typical speed of a tsunami to travel is
500mph
tsunamis propagate across the open ocean as
shallow water waves
the restoring force on capillary waves is
surface tension
the earth is shaped like an
ellipsoid due to centrifugal force
how does the geoid change over a larger underwater sea-mount
dome
is cold and fresh, or warm and salty water denser
it depends
in the open ocean northern hemisphere, mid latitude winds tend to blow from west to east, while lower latitude winds tend to blow to east to west. the Ekman transport between them is
convergent
hurricanes in the northern hemisphere are caused by regions of extreme low pressure. they rotate
counterclockwise due to Coriolis force
pressure forces make water want to flow
from high to low pressure
once water starts moving the Coriolis force makes water in the northern hemisphere want to flow to the
right
when pressure force and Coriolis force are combined in north
water flows clockwise around high pressure areas
also if an object in the northern hemisphere moves eastward, the Coriolis force on that object it
southward
if you were hovering over antarctica which way would you see the average winds blowing
clockwise
which direction is the net Ekman transport in the surface waters near Antarctica associated with the wind`
equatorward away from antarctica
as you move northward across the Antarctic circumpolar current from Antarctica, the ocean surface goes
up by 2m
pressure gradient near Antarctica wants to push water
poleward
geostrophic flow around Antarctica flows
clockwise
Ekman transport results from a balance between
wind stress and coriolis
the gulf stream flows from south to north so the sea surface height slopes
sea surface higher to the east
if the wind is blowing northward along the east coast of America, the Ekman current of the ocean flows
away from coast, upwelling
what type of bonds hold H and O together
covalent
what occurs when light is bounced between air and water molecules, dust and other objects
scattering
the more adundant component in a solution is called a
solvent
as salinity increases, freezing point
decreases
after hydrogen and oxygen what is the most abundant constituent of seawater
chlorine
pure water is most dense when at
4C
where do salts in seawater come from
volcanism
weathering
biological processes
is sodium conservative or non conservative
conservative
cold water can hold more or less gas in solution than warm water
more
seawater pH
8
calcium carbonate solubility _____ with depth
increases
the tendency of a substance to resist a change in temperature with the gain or loss of heat is also known as
thermal inertia
a place where water infiltrates into a subspace formation is called
recharge area
the local aquifer is the main source of potable water in SD county
false
examples of desalination process
freezing
distillation
reverse osmosis
what proportion of the pollution entering the ocean comes from human activities on land
75%
what factors determine how dangerous a pollutant is
quantity
toxicity
persistence
spills of refined petroleum products are generally more harmful then those of crude oil
true
