layers of the earth
name the thickest layer of the earth
the mantle
what is the name of the break or fracture in the ground that occurs when the earths tectonic plates move or shift
fault lines
who proposed the process of seafloor spreading?
Harry Hess
what instrument is used to detect and record earthquakes?
name a place where continental rifting is currently taking place?
east africa
the crust and the upper mantle together form the ____.
lithosphere
name 2 of the types of crust that collide in a subduction zone
oceanic crust and continental crust
or
oceanic crust and oceanic crust
polarity reversal (the earths magnetic field changing direction,) occurs approximately every _____ years.
a. 2 million
b. 22,000
c. 6000
d. 1.7 billion
b. 22,000 (years)
Magma is liquid rock inside a volcano. Lava is liquid rock (magma) that flows out of a volcano.
which of the following is an example of a convergent boundary?
a. San andres fault
b. The rift valley
c. Mid-Atlantic Ridge
d. The Himalayas
d. The Himalayas
state the difference between mechanical and compositional layers
compositional layers- elements in which the layers are composed of
whilst
mechanical layers- how the layers within the earth behave.
name the 4 pieces of evidence that Alfred Wegener proposed to support the theory of continental drift
- coastlines of continents appear to fit together like a jigsaw puzzle
- fossils of the same species have appeared on different continents
- identical rock formations and features were found on different continents
- evidence of drastically changed climates
During subduction between continental plates and oceanic plates, which plate sinks under the other and why?
the oceanic plate sinks due to its higher density and low buoyancy.
what type of rock is formed when magma cools and crystallises?
igneous rock
in which U.S. state can the largest volcano in the world be found?
Hawaii (Mauna Loa volcano)
what are the two main metals the earths core is made up of?
iron & nickel
what are mid-ocean ridges and why does oceanic crust form there?
mid-ocean ridges are underwater mountain ranges formed by tectonic plates, plates are diverging near mid ocean ridges therefore magma rises between the plates.
name the 3 important pieces of evidence supporting Hess's theory of seafloor spreading and state how they .
- sediment thickness; as you move away from the ridges, sedimentary rock layers on the ocean floor become thicker.
- magnetic stripping; majority of rocks contain the mineral magnetite. When molten rock solidifies, all the magnetite particles line up with Earth’s current magnetic field that point in the same direction.
- age of the sea floor; new crust spreads outwards which determines the age of the seafloor.
state the three types of seismic waves discussed and rate them from most to least destructive
- surface waves
- s-waves
- p-waves
(in order of destructiveness)
considering the theory of continental drift ,which 2 plates would have been found sharing coastlines with Australia approximately 200 million years ago?
Antarctic and Indian Plate