Chapter 2 Internal Energy and Plate Tectonics
Nuclear fusion
The reaction in which two or more atomic muscles collide and join to form a new type element.
Stony meteorites
The rocks of the mantle have a composition similar to that of ____.
plate tectonics
The study of movements and interactions of the plates.
Curie point
The temperature below which a mineral becomes magnetized is called the ____.
Elastic, ductile, and brittle
The three types of strain are
Sequence of lava flows
The timescale of magnetic reversals was developed by measuring the magnetism in ____.
Lengths of time between
The widths of magnetized sea floor stripes correlate well with the ____ reversals of Earth's magnetic field.
Isostasy
This concept explains how mountain ranges float on the denser mantle and will rise up when erosion removes rock material from the mountains.
Increase
Water depths ____ systematically with sea floor age.
Volcanic island arc
What feature forms when one oceanic plate subduction beneath another?
The sinking of a slab of oceanic lithosphere under less-dense lithosphere
What is subduction?
Impact of the young Earth by a Mars-sized object
What is the melt current hypothesis for how the moon was formed?
Subduction zone
What kind of plate boundary is most commonly associated with deep earthquakes?
He noted that natural processes, such as erosion; were very slow.
What led James Hutton to propose the Earth must be extremely old?
Heat
When radioactive isotopes decay, energy is released in the form of
Where the sea floor is oldest
Where are the deepest parts of the ocean found?
Melting of rock; formation of even larger objects; loss of volatiles to space
Which of the following are consequences of collisions of large objects during the formation of the Solar System?
Radioactive decay; gravitational energy; impact energy; differentiation into layers
Which of the following are sources of heat generated during the formation of the Earth?
Immanuel Kant in 1755
Which of the following astronomers introduced the most widely accepted hypothesis regarding the origin of the Solar System?
Magnetic reversals are generated by random changes in the liquid outer core.
Which of the following statements about magnetic reversals is true?
Volcanic continental arc; oceanic trench
Which of these are features that form when an oceanic plate subduction beneath a continental plate?
Impact energy; gravitational energy; radioactive decay
Which of these are the three sources of the energy that flows from the Earth's interior to its surface?
Oceans
Which of these has the lowest density?
Seafloor spreading
The progressive deepening of the oceans away from the mid ocean ridges is evidence for ____.
Half-life
The rate of radioactive decay is measured by the ____ of isotopes.
Rate of human fingernail growth
The rates of tectonic plate movements are comparable to the
Seafloor spreading
The paleomagnetism timescale and the patterns of magnetism on the seafloor provide compelling evidence of ____.
Hot spot
A place on Earth where a plume of magma has risen up from the mantle and through a plate to reach the surface.
Lithosphere
A rigid layer made up of the uppermost part of the mantle and the crust.
Mantle
A thick layer of dense rock that comprises 83% of the Earth's volume and 67% o its mass.
Actualism
An alternative to the term uniformitarianism. This term is preferred by some scientists because it does not assume that the rate of processes is constant.
Panthalassa
Approximately 220 million years ago, the continents were joined together into one supercontinent known as Pangaea. This supercontinent was surrounded by an ocean named ____.
Thicker
Away from the oceanic ridges the layer of sediment covering the seafloor becomes ____.
200 millions years old
The oldest rocks on the ocean floors are approximately
Subduction
Earthquakes that occur along inclined planes adjacent to deep-ocean trenches are evidence for ____.
Planets
Formed through collisions of particles that fused together, forming larger objects.
1.5
Geologic studies suggest that the outer layers of the Earth were active in the process of plate tectonics by at least ____ billion years ago.
continental drift
The process of the continents moving, spitting, and recombine is known as
Volcanic activity above a hot spot
How did the chain of volcanic islands and seamounts form?
Convection cells
In the mantle form when hit mantle material rises, moves laterally, and then sinks when it becomes cold.
4.4; 3.5
It is likely that oceans and small continents existed on Earth by ____ billion years ago and that life was present by ____ billion years ago.
Collisions of matter within a rotating cloud of gas and dust
It is widely believed that the Solar System formed through
Iron
Minerals that grow as crystals in cooling lava can become magnetized if they contain ____.
Lava
Molten rock erupted from a volcano
The Earth's mantle
Most current hypothesis for how the Moon was formed would suggest that it is mostly made up of material from
At plate boundaries
Most earthquakes occur ____.
65 million years.
Much of the present ocean floor was created during the last
Elastic strain
Occurs when the differences in stress coming from different directions are low.
Yield stress
Permanent strain occurs when the stresses applied to a rock exceed its ____.
Tectonics
Taken from the Greek word meaning "to build," the term describes the building of topography and the deformation and movement within Earth's outer layers.
False
The Earth formed its compositional layers by accretion of first iron-rich materials, followed by rocky materials, and finally by ices.
4.54 billion years
The Earth has existed as a coherent mass for ____.
Iron
The Earth's core is composed mostly of the element ____, which came from meteorites.
Solid; liquid
The Earth's core, which is composed mostly of iron, is divided into the ____ inner core and the ____ outer core.
Hydrogen; helium
The Sun is predominantly composed of the elements ____ and ____.
False
The best fit of the continents to form Pangaea occurs when you match the shorelines.
Strain
The change in shape of a material in response to an applied force is called
5 million years
The collision of Earth with a Mars-sized body that formed our Moon occurred approximately ____ after the Earth is believed to have formed.
Uniformitarianism
The concept that the same laws and processes have been operating on Earth throughout geologic time.
0.1%
The continents make up approximately ____ of Earth's total volume.
Seafloor spreading
The creation of new oceanic lithosphere at an oceanic ridge and its movement away from the ridge is known as ____.
Subduction zones
The deepest parts of the oceans occur in elongate narrow trenches that are associated with ____.
Continental drift
The discovery of sea floor spreading provided the mechanism that was missing in Wegener's hypothesis of ____.
The boundary between low-density continental rocks and higher-density oceanic rocks.
The edge of a continent is found at
Earthquakes
The edges of the tectonic plates can easily be defined by mapping the locations of ____.
Slab pull
The effect of a down-going plate at a subduction zone on the lateral motion of the plates.
Stress
The force per unit area applied to an object.
Mercury; Earth; Mars; Venus
The four inner planets are
Hydrogen, d other frozen materials
The four outer planets of the Solar System are mostly composed of
Spreading centers
The great mountain ranges that extend more than 65,000km across the ocean bottoms are formed at ____.
Impact energy
The heat produced by masses colliding to form the Earth is referred to as
Convection cells
The lateral movement of the tectonic plates occurs as they ride along on top of ____ in the mantle.
Gravitational pull
The lateral spreading of the plates away from the elevated mid ocean ridge is driven in part by ____.
Strengths
The lithosphere, asthenosphere, mesosphere, outer core, and inner core are layers of the Earth that are distinguished from one another by their ____.
The symmetry of the stripes on either side of the volcanic ridge
The most striking feature of the magnetic signature of the sea floor is
Pangaea
The name of the single supercontinent proposed by Wegener.
Grain of Zircon from Australia
The oldest Earth material, dated at 4.37 billion years old, is a
Lavas contain radioactive elements that can be used to date them; lavas become magnetized as they cool below the Curie point
Why are sequences of layered lava flows so useful in the construction of the timescale of magnetic reversals?
The accumulation of sediments over time adds weight to the seafloor; older oceanic crust is denser and thus sits lower on the asthenosphere
Why do ocean water depths increase away from the mid ocean ridge?
Rocks are poor conductors of heat.
Why hasn't all of the heat generated during the formation of the escaped, even after 4.6 billion years of Earth history?
Early Earth rocks are difficult to find due to plate tectonics.
Why is it difficult to study the early history of the Earth?
Early gravitational compaction; great abundance of radioactive isotopes; more frequent meteorite impacts
Why was Earth's Internal Energy higher during its early history?