Geo 303 Final

What is the age of the oldest intact rocks that have been found on Earth? -4.6 Ga (billion years) -4 Ga -2 Ga -10,000 years

How does the Doppler Effect tell us about the motion of galaxies? -Light from distant galaxies is fainter the farther away they are, just like an ambulance siren fading in the distance as it moves away. -Light from galaxies moving away from us has a higher frequency (i.e. looks bluer) than light from galaxies that are moving toward us. -Light from galaxies moving away from us has a lower frequency (i.e. looks redder) than light from galaxies that are moving toward us. -Galaxies make a high-pitched sound as they move toward us, and a low-pitched sound as they move away.

The earliest matter in the universe was composed of mostly: -hydrogen and oxygen -hydrogen and iron -hydrogen and helium -hydrogen and silicon

The earth is referred to as a layered planet because: -progressive accretion of materials of differing composition during the formation of the solar system led to a series of compositional "layers" within the planet -the Earth's atmosphere forms a thin layer surrounding the homogeneous planet -differentiation during and following planetary accretion allowed the materials making up the early Earth to separate based upon their density -plate tectonics produces stratigraphic sequences that look like "layers" in the Earth's surface crust

What is the most probable origin of earth's moon? -condensed from material expelled from a gigantic collision between the proto-earth and a Mars-size impacting body -moon fully made elsewhere in the solar system, and later captured into an earth-circling orbit -the earth already differentiated, and then the moon extracted out of the body of the earth -moon's substance propelled into orbit by massive volcanic eruptions in early earth history

According to current scientific understanding, the age of our universe is: -about three times older than the age of the earth; -similar to the age of the earth based on the similarity between the ages of the earth and meteorites -completely unknown and based only on hypothetical reasoning -infinite

All of the following statements about the atmosphere of the early Earth are correct, except one. Which statement is incorrect? -The earliest atmosphere was probably mainly hydrogen and helium, but the Earth's weak gravity could not keep those gases from escaping. -The early atmosphere is thought to have been blown away by the solar wind. -The development of Earth's magnetic field caused the atmosphere at that time to be driven off. -After the early atmosphere was lost, it was replenished, with the most likely source being gases trapped beneath the Earth surface and released by volcanism.

The Earth's layers are composed of which of the following, from outside to inside: -(Si,Al,O); (Mg,Fe, Al,O); (Fe, Ni) -(Mg,Fe, Al,O); (Si,Al,O); (Fe, Ni) -(Fe, Ni); (Mg,Fe, Al,O); (Si,Al,O) -(Fe, Ni); (Si,Al,O);(Mg,Fe, Al,O)

What information can meteorites provide about Earth? (select in all that are correct) -changes in Earth's orbit -the composition of Earth's core -Earth's age -the average composition of the whole Earth

According to nebular theory, the progression from planetesimal to full-fledged planet is propelled mainly by which of the following? -gravity -nuclear fusion -heat -nucleosynthesis

Alfred Wegner is best remembered for -being the first to put together a hypothesis for continental drift based on a variety of scientific data sources -being the first to prove scientifically that continental drift occurs -being the person to discover mid ocean ridges -all of the above

Which part of the earth do geophysicists think generates its magnetic field? The earth's: -core -mantle -crust -hydrosphere

Which statement about magnetic reversals is correct? -A reversal occurs when the field becomes so strong that it becomes unstable and breaks apart. -Reversals are random; we cannot predict when the next reversal will occur. -On a geologic time scale, reversals occur very gradually. -Today the sun rises in the east, but after a reversal the sun will rise in the west.

Magnetic declination refers to: -the instability and motion of the Earth's magnetic field over time -the fall in the overall strength of the magnetic field right before a reversal -the angular difference between a compass reading at a certain location and the direction of the True, or Geographic North Pole -the angle at which the magnetic lines of the Earth's gravitational field plunge downward

Why can the earth's inner core not act as a permanent magnet? -It is too deep, and under too much pressure -Its temperature is far hotter than the Curie temperature for any magnetic material -Permanent magnets are made artificially, not of natural origin -The inner core, with the shape of a sphere, cannot have magnetic poles because every point on a sphere is like every other point

If a flow of basalt were to cool and crystallize at the magnetic South Pole, what would be the orientation of its locked-in magnetic lines of force? -vertical to the earth's surface -horizontal, pointed N-S -at an angle of 45° to the surface -There is no earth magnetism at the South Pole

Over the past 30 thousand years, what has been the relationship between the North magnetic pole and North geographic (rotational) pole? -The rotational pole has always been in the Arctic Ocean and the magnetic pole has always remained fixed in northern Greenland. -Although the magnetic pole is constantly moving in random directions, it always stays near to the rotational pole. -Although the geographic pole is constantly moving in random directions, it always stays near to the magnetic pole. -There is no systematic relationship; at any given moment, the magnetic pole might be "anywhere."

The geodynamo generates electric currents within the liquid outer core that are responsible for: -generating most of the earth's magnetic field -suspending the inner core magnetically to keep it at the center of the earth -heating the outer core to make it a liquid -heating the mantle to generate lava that feeds volcanoes of the Pacific Ring of Fire

Which one of the following is not a piece of evidence used by Wegner to argue for continental drift? -Fossils of the same species of ancient migratory bird are found on the two continents. -Similar rock types and rock ages are observed across the Atlantic between Africa and South America. -Large-scale structures like faults on either side of the Atlantic would link up if the ocean basin were closed. -magnetic reversals in ocean floor basalts show a mirror imagine across mid ocean ridges

the difference between a theory and a hypothesis is -a hypothesis is well tested -a theory is well tested -a theory has been proven -they are essentially the same

Using the figure above, predict the future location of the red circle. Note that the red circle will move, but the letters will not. -A -B -C -D

As the map below shows, the oldest seafloor is generally less than 200 million years old. Why? -Heat from volcanic activity remelts parts of the ocean floor once it becomes 200 million years old. -All oceanic lithosphere eventually gets subducted beneath the continents by the time it is 200 million years old. -According to geological dating methods, the entire Earth is less than 200 million years old. -When oceanic floor becomes older than 200 million years, it turns into continental crust.

The Mariana Trench is the deepest place on Earth. How was this deep-sea trench created? -subsidence of cold, dense oceanic crust -subduction of the Pacific Plate -creation of a large crater by the impact of an asteroid -spreading of the Pacific Plate along the East Pacific Rise

This diagram shows the South Island of New Zealand. The Alpine fault is a plate boundary that cuts across the land in a northeasterly-southwesterly direction. Gold was discovered in distinctive rocks near Queenstown on the southeast side of the fault. The same distinctive gold-bearing rocks are found on the northwestern side of the fault, but they lie about 480 km to the northeast. Evidence suggests that slip along the fault has been occurring for about 20 million years. Most of the displacement on the fault is strike-slip (only about 10 km of vertical motion has occurred). What kind of plate boundary is this fault? -dominantly divergent -dominantly convergent -dominantly transform

Over 20 million years, the total offset across the fault is 480 kilometers. What is the average rate of motion along the fault? -2400 cm per year -2.4 cm per year -0.000024 cm per year

This image shows the Red Sea, which separates northeastern Africa from the Arabian Peninsula. Currently, the Arabian peninsula is moving northeast relative to Africa. Which of the following processes is responsible for the formation of the Red Sea? -transform faulting -rifting followed by seafloor spreading -thickening of the crust due to collision -subduction

Select statements true of the Hawaiian Hot Spot. -It is no longer active. -It produced the Emperor Seamounts. -It produced the Hawaiian Islands. -It has moved beneath the Pacific Plate over geologic time.