Exam 1 Flashcards
(48 cards)
The interior part of the Earth that is iron/magnesium rich, and has a plastic nature/rheology is the..
asthenosphere
How do we think we know where major physical boundaries are within the earth?
-deepwell drilling
-interpretation of seismic wave data
-calculations based on an ideal earth model
-measurement of the earth’s gravity field.
interpretation of seismic wave data
A large meteorite is proposed to have struck the earth ~65 million years ago, resulting in a mass extinction that killed off ~50% of all species, including the dinosaurs. Regarding this event, which of the following statements is false?
-One piece of evidence for the collision of a meteorite at 65 Ma is the presence of the element iridium in rocks at that time interval, at many locations throughout the world.
-The impact crater has been located off the coast of the Yucatan Peninsula
-Based on the size of the crater, the meteorite is interpreted to have been 10-50 km in diameter.
-It is hypothesized that a dust cloud was ejected into the atmosphere that was present for approximately a million years
-gravity studies of the rocks helped confirm the existence of the crater.
It is hypothesized that a dust cloud was ejected into the atmosphere that was present for approximately a million years.
In the earth’s crust, what is the average increase in temperature per 1 kilometer depth?
25 deg C
Place the following events in the proper order in which they occurred (according to conventional scientific interpretation of the fossil record), from oldest to youngest.
-dinosaurs
-fish
-insects
-bacteria
-mammals
- Bacteria Evolve
- Fish Evolve
- insects evolve
- dinosaurs evolve
- mammals evolve
Which of the following statements about the earth’s crust is false?
-continental crust is thicker than oceanic crust
-continental crust can be much, much older than oceanic crust
-continental crust is more dense than oceanic crust
-continental crust and oceanic crust have different average compositions.
Continental crust is more dense than oceanic crust.
Use the following diagram of the earth’s “Mechanical Layers” to answer the following questions.
E. (earth’s crust) - which layer is rigid and includes the crust and upper mantle
D. (2nd layer) - Which layer is the asthenosphere
C. (3rd layer) - Which layer is NOT the asthenosphere, but part of the mantle.
B. (4th layer) - Which layer is liquid
A. (Core layer) - No option
According to conventional scientific interpretation, the Earth is approximately 4.5 billion years old.
True
According to conventional scientific interpretation, approximately how long ago did the Big Bang occur?
13.7 Ga
What was the immediate significance of the evolution of photosynthesizing organisms?
It resulted in the release of Oxygen in the atmosphere.
What does the abbreviation Ma stand for?
Millions of years
Which of the following statements is false?
-The moon is thought to have been formed when a large meteorite impacted and blasted off a huge chunk of the earth
-The earth rotates around an axis that is tilted ~23.5 deg relative to the ecliptic plane.
-The oldest piece of Earth material that has been scientifically dated is a zircon crystal with an age of 4,404,000,000 yo
-It is thought that the oceans initially formed about 4 billion years ago.
-The first life is thought to have evolved ~600 million years ago.
The first life is though to have evolved ~600 million years ago.
Continental crust sticks up above the ocean’s surface and oceanic crust does not. The only reason for this is the thickness differences of the two different types of crust.
False
(Density differences also play a role. Because of oceanic crust’s greater density it “sinks” further into the mantle than does the more buoyant continental crust. This is the principle of Isostasy.
Match the following locations with their tectonic association.
(Convergent boundary, divergent boundary, or transform boundary)
San Adreas Fault
Himalaya
East Africa Rift
Mid Ocean Ridge
Japan
Blanco Fracture Zone
San Andreas Fault - Transform Boundary
Himalaya - Convergent Boundary
East Africa Rift - Divergent Boundary
Mid Ocean Ridge - Divergent Boundary
Japan - Convergent Boundary
Blanco Fracture Zone - Transform Boundary
Which of the following statements is false?
-Convergent plate boundaries are where two plates collide with each other
-divergent plate boundaries are where two plates move apart from one another
-Transform plate boundaries is where two plates move side by side.
-Hotspots do not occur at plate boundaries
-Hotspots do not occur at plate boundaries
What direction is the plate moving? (refer to map - Basho Island is an active volcano over a hotspot. The other islands, including Nesmith Island, are extinct volcanoes.)
Northeast
Very deep earthquake (>100km) occur where:
subduction zones
Why would oceanic volcanoes and seamounts within tectonic plates tend to form in a line?
The plate they are on is moving over a stationary hotspot.
Which of the following is NOT used as evidence for plate tectonics?
-magnetic reversals on the ocean floor
-Carbon dioxide levels in the atmosphere
-distribution of fossils
-earthquake and volcano distribution
-regional geologic patterns
Carbon dioxide levels in the atmosphere.
Which of the following statements is true?
-Earthquakes beneath subduction zones occur in random locations
-Volcanoes above subduction zones occur in disorganized clusters
-An ocean trench can form at a convergent plate boundary where a subduction plate physically drags down the surface of the earth.
-A subduction zone cannot occur where two oceanic plates converge.
-All of the above are true statements.
An ocean trench can form at a convergent plate boundary where a subduction plate physically drags down the surface of the earth.
Nesmith Island is an extinct volcano ~10 million years old. Appx how fast is the plate moving at this location?
Take distance (measure using scale) divided by time. In this question it was 100 km distance so the answer was 10km/m.y.
Which of the following locations is NOT associated with subduction zones:
The Cascade Mountains
The Andes Mountains
The Aleutian Islands
Hawaii
Philippines
Hawaii (hotspot)
Which of the following is not true:
-The average age of the continental crust is much older than that of the oceanic crust.
-The mantle is more dense than the oceanic crust
-oceanic crust is much thinner than continental crust.
-The oceanic crust is dominantly composed of granite.
The oceanic crust is dominantly composed of granite.
Which scientist was the first person to use geologic evidence to propose that the continents were drifting apart from a supercontinent he called Pangaea?
Alfred Wegener
