EAPS 106 EXAM 1 QUESTIONS WITH VERIFIED
ANSWERS
How did Earth acquire its internal heat?
The process of planet accretion results from lots of collisions, each producing heat. Combined
with heat from the decay radioactive elements, the interiors of all new planets become so hot
inside that they melt.
Earth will never lose its heat prior to the Sun going Red Giant stage
Why is the interior of Earth layered?
When everything was melted, the dense elements like iron sank to the center forming an iron
core, and the lighter elements like silicon and oxygen rise to form a rocky mantle and crust.
Process is called differentiation. (spinning water bottle experiment)
Why is the outer core a liquid and the inner core a solid?
The outer layer is the only layer that remains hotter than its melting temperature. The inner core
is at a higher temperature, but the melting temperature is also higher due to the greater pressure
at the increased depth.
What are the lithosphere and asthenosphere?
Lithosphere is a strong outer shell of the Earth consisting of the cold crust and uppermost mantle.
The breaking of the lithosphere into pieces or "plates" and the manner in which they move
around the surface of the Earth gives rise to the term "plate tectonics".
The asthenosphere underlies the lithosphere and is hot enough to flow like a fluid (even though it
remains a solid). It is the weakness of the asthenosphere that allows tectonic plates to slide
around the surface of the Earth.
What evidence did Wegner use to suggest that the continents drift?
North and South America coastlines fit with Europe and Africa
Identical volcanic flows appear on both sides of the Atlantic
Fossils of non-swimmers found on both sides of the modern oceans
How do we know that our magnetic field has reversed itself many times?
Crystals in lava record the direction to the magnetic poles at the time of each eruption, There are
also magnetic lineations on the seafloor that show new oceanic plates are created at mid ocean
ridges, giving more evidence of continental drift.
Black bands: normal magnetic field
, White bands: reversed magnetic field
Big bands - no volcanic rocks to date
What is a mid-ocean ridge, a subduction zone, and a transform plate boundary
Mid ocean ridges are places where magma comes up and forms new oceanic plates. They're
referred to as divergent margins since the plates move away from each other.
Subduction zones are the most important tectonic feature on Earth. Their relative motion gives
rise to the highest mountains, the deepest valleys, the most active volcanoes, and the largest
earthquakes. Oceanic plates get recycled back into the mantle at subduction zones, allowing
continents to drift over the ocean basins. Subduction zones are referred to as convergent margins
since the plates move toward each other.
Transform plate boundaries are where two plates laterally slide past each other.
What is a passive plate margin?
When a boundary between continental crust and oceanic crust is not a plate boundary, it is
referred to as a passive margin. Passive margins are the locations where a continent split into two
and an oceanic plate grew between them as the two parts drifted away from each other.
What kind of plate boundary is the San Andreas Fault?
Transform plate boundary
Where is Hawaii located relative to plate boundaries?
Hawaii is located on the Pacific plate near the center which is far from the plate boundaries.
Note: Volcanoes exist here because it's a hot spot not because of a plate boundary.
What is a supercontinent?
A supercontinent is many continents joined as one.
How did plate tectonics influence the evolution of whales and dolphins?
The evolution of dolphins and whales appears tied to the shallowing of the Tethys Sea when
India collided into Asia.
What are the basic processes of conduction, convection, and radiation?
Convection: Heat transfer through fluid motions of liquids and gases, as well as solids that flow
like a fluid (which is referred to as solid state convection).
Conduction: Heat transfer through a solid through the spread of vibrations on the atomic scale.
Radiation: heat transfer through electromagnetic waves (light) through a transparent (clear)
medium.
ANSWERS
How did Earth acquire its internal heat?
The process of planet accretion results from lots of collisions, each producing heat. Combined
with heat from the decay radioactive elements, the interiors of all new planets become so hot
inside that they melt.
Earth will never lose its heat prior to the Sun going Red Giant stage
Why is the interior of Earth layered?
When everything was melted, the dense elements like iron sank to the center forming an iron
core, and the lighter elements like silicon and oxygen rise to form a rocky mantle and crust.
Process is called differentiation. (spinning water bottle experiment)
Why is the outer core a liquid and the inner core a solid?
The outer layer is the only layer that remains hotter than its melting temperature. The inner core
is at a higher temperature, but the melting temperature is also higher due to the greater pressure
at the increased depth.
What are the lithosphere and asthenosphere?
Lithosphere is a strong outer shell of the Earth consisting of the cold crust and uppermost mantle.
The breaking of the lithosphere into pieces or "plates" and the manner in which they move
around the surface of the Earth gives rise to the term "plate tectonics".
The asthenosphere underlies the lithosphere and is hot enough to flow like a fluid (even though it
remains a solid). It is the weakness of the asthenosphere that allows tectonic plates to slide
around the surface of the Earth.
What evidence did Wegner use to suggest that the continents drift?
North and South America coastlines fit with Europe and Africa
Identical volcanic flows appear on both sides of the Atlantic
Fossils of non-swimmers found on both sides of the modern oceans
How do we know that our magnetic field has reversed itself many times?
Crystals in lava record the direction to the magnetic poles at the time of each eruption, There are
also magnetic lineations on the seafloor that show new oceanic plates are created at mid ocean
ridges, giving more evidence of continental drift.
Black bands: normal magnetic field
, White bands: reversed magnetic field
Big bands - no volcanic rocks to date
What is a mid-ocean ridge, a subduction zone, and a transform plate boundary
Mid ocean ridges are places where magma comes up and forms new oceanic plates. They're
referred to as divergent margins since the plates move away from each other.
Subduction zones are the most important tectonic feature on Earth. Their relative motion gives
rise to the highest mountains, the deepest valleys, the most active volcanoes, and the largest
earthquakes. Oceanic plates get recycled back into the mantle at subduction zones, allowing
continents to drift over the ocean basins. Subduction zones are referred to as convergent margins
since the plates move toward each other.
Transform plate boundaries are where two plates laterally slide past each other.
What is a passive plate margin?
When a boundary between continental crust and oceanic crust is not a plate boundary, it is
referred to as a passive margin. Passive margins are the locations where a continent split into two
and an oceanic plate grew between them as the two parts drifted away from each other.
What kind of plate boundary is the San Andreas Fault?
Transform plate boundary
Where is Hawaii located relative to plate boundaries?
Hawaii is located on the Pacific plate near the center which is far from the plate boundaries.
Note: Volcanoes exist here because it's a hot spot not because of a plate boundary.
What is a supercontinent?
A supercontinent is many continents joined as one.
How did plate tectonics influence the evolution of whales and dolphins?
The evolution of dolphins and whales appears tied to the shallowing of the Tethys Sea when
India collided into Asia.
What are the basic processes of conduction, convection, and radiation?
Convection: Heat transfer through fluid motions of liquids and gases, as well as solids that flow
like a fluid (which is referred to as solid state convection).
Conduction: Heat transfer through a solid through the spread of vibrations on the atomic scale.
Radiation: heat transfer through electromagnetic waves (light) through a transparent (clear)
medium.
