EESA06 MIDTERM QUESTIONS & ANSWERS
Why does oceanic crust sit at a lower elevation than continental crust? - answers -
basalt is denser than the rockd in the continental crust
What is the atlantic ocean an example of? - answers -passive margins
Example of mature ocean basin - answers -the atlantic ocean
Iceland is made by... - answers -the doming of the mid atlantic ridge above a rising
mantle plume
Where is a mid ocean ridge above sea level? - answers -iceland
Hydrothermal circulation - answers -seawater filters down into the crust though faults in
the sea floor where it is heated and expelled back up to the surface which can provide
nutrients that support deep water organisms
T or f: the continents are generally much older than the oceans - answers -true
How do volcanic arcs form? - answers -the subduction slab or oceanic crust descends
into the mantle and triggers melting and magma production
Example of oceanic-continental convergence - answers -the mariana trench and arc
The mariana trench - answers -the deepest feature on planet earth and marks the point
where the pacific and philippine plates meet
T or f: oceanic crust is more buoyant than continental crust - answers -false
Oceanic crust is significantly less buoyant than continental crust
How do we measure the symmetrical nature of sea floor spreading? - answers -
measure the polarity of the magnetic field of magnetite crystals in basalt
How do oceans shrink? - answers -the plate with oceanic crust subducts when met with
a plate with continental crust
Examples of oceanic-continental convergence - answers -much of the pacific ring of
fire, the cascades subduction zone
T or f: earthquakes can't be produced below 700km - answers -true
Below about 700km, rocks begin to deform plastically, rather than fracturing or breaking,
and therefore tend not to produce earthquakes
, Subduction if the pacific plate creates... - answers -the pacific ring of fire (the region of
intense earthquake and volcanic activity)
Where do earthquakes predominantly occur? - answers -plate margins
Where do shallow earthquakes occur? - answers -divergent and transform margins
T or f: convergent margins produce stronger earthquakes than divergent margins -
answers -true
The benioff zone - answers -subduction zones often have a characteristic pattern of
increasing earthquake depth in the direction the plate is sinking
What created the largest mountain ranges on earth? - answers -continental-continental
convergence
Orogeniesa - answers -large mountain belts created by two continental plates
crumpling and welding together in large mountain belts
The mediterranean ocean is the remnant of an ocean basin called... - answers -the
tethys ocean
Which ocean separated europe from africa? - answers -the tethys ocean/the
mediterranean
T or f: the mediterranean is growing - answers -false
The mediterranean has been shrinking through the process of subduction
Examples of continental-continental convergence - answers -the himalayas, the alps,
the appalachians orogen, the grenville orogen
What are the greyish-coloured rocks of the matterhorn made out of? - answers -african
crust which has been thrusted onto the eurasian plate
What are the reddish-coloured streaky looking rocks in the foreground of the
matterhorn? - answers -highly deformed ophiolites rocks, made of a slice of ocean floor
which has been inducted northwards onto the eurasian plate as italy collided with
europe
Lithosphere - answers -a layer made up of the rigid uppermost part of the mantle and
the crust.
T or f: the "crust" of the earth is silica-rich and low-density - answers -true
Why does oceanic crust sit at a lower elevation than continental crust? - answers -
basalt is denser than the rockd in the continental crust
What is the atlantic ocean an example of? - answers -passive margins
Example of mature ocean basin - answers -the atlantic ocean
Iceland is made by... - answers -the doming of the mid atlantic ridge above a rising
mantle plume
Where is a mid ocean ridge above sea level? - answers -iceland
Hydrothermal circulation - answers -seawater filters down into the crust though faults in
the sea floor where it is heated and expelled back up to the surface which can provide
nutrients that support deep water organisms
T or f: the continents are generally much older than the oceans - answers -true
How do volcanic arcs form? - answers -the subduction slab or oceanic crust descends
into the mantle and triggers melting and magma production
Example of oceanic-continental convergence - answers -the mariana trench and arc
The mariana trench - answers -the deepest feature on planet earth and marks the point
where the pacific and philippine plates meet
T or f: oceanic crust is more buoyant than continental crust - answers -false
Oceanic crust is significantly less buoyant than continental crust
How do we measure the symmetrical nature of sea floor spreading? - answers -
measure the polarity of the magnetic field of magnetite crystals in basalt
How do oceans shrink? - answers -the plate with oceanic crust subducts when met with
a plate with continental crust
Examples of oceanic-continental convergence - answers -much of the pacific ring of
fire, the cascades subduction zone
T or f: earthquakes can't be produced below 700km - answers -true
Below about 700km, rocks begin to deform plastically, rather than fracturing or breaking,
and therefore tend not to produce earthquakes
, Subduction if the pacific plate creates... - answers -the pacific ring of fire (the region of
intense earthquake and volcanic activity)
Where do earthquakes predominantly occur? - answers -plate margins
Where do shallow earthquakes occur? - answers -divergent and transform margins
T or f: convergent margins produce stronger earthquakes than divergent margins -
answers -true
The benioff zone - answers -subduction zones often have a characteristic pattern of
increasing earthquake depth in the direction the plate is sinking
What created the largest mountain ranges on earth? - answers -continental-continental
convergence
Orogeniesa - answers -large mountain belts created by two continental plates
crumpling and welding together in large mountain belts
The mediterranean ocean is the remnant of an ocean basin called... - answers -the
tethys ocean
Which ocean separated europe from africa? - answers -the tethys ocean/the
mediterranean
T or f: the mediterranean is growing - answers -false
The mediterranean has been shrinking through the process of subduction
Examples of continental-continental convergence - answers -the himalayas, the alps,
the appalachians orogen, the grenville orogen
What are the greyish-coloured rocks of the matterhorn made out of? - answers -african
crust which has been thrusted onto the eurasian plate
What are the reddish-coloured streaky looking rocks in the foreground of the
matterhorn? - answers -highly deformed ophiolites rocks, made of a slice of ocean floor
which has been inducted northwards onto the eurasian plate as italy collided with
europe
Lithosphere - answers -a layer made up of the rigid uppermost part of the mantle and
the crust.
T or f: the "crust" of the earth is silica-rich and low-density - answers -true
