#4. Explain why the discovery of the fossil remains of mesosaurus in both South America and Africa, but nowhere else, supports the continental drift hypothesis.
Well mesosaurus were able to swim well enough so they can cross the vast ocean currently separating africa and south America, it remains should be found on other continents. But in the other hand this was not the case since we can tell that south America and africa were once joined during the time period that animals existed.
#9. What are the three major types of plate? Describe the relative plate motion at each of these boundaries.
1st there is Divergent boundaries which are plates are moving apart. 2nd Convergent boundaries where plates are moving together 3rd are transform boundaries where plates slide past one another along faults.
#18. What is the age of the oldest sediments recovered by deep-ocean drilling? How do the ages of these sediments compare to the ages of the oldest continental rocks?
180 million years ago. By 4 billion years old on the continent.
#20. Briefly describe then three mechanisms that drive plate motion.
1st is the Slab which pulls to older slabs of oceanic that are more dense sink into the asthenosphere and pull the trailing plate along. 2nd is the ridge which is a push which casues slabs to move down the flanks of the ridge. 3rd is Whole-mantle convection in which cold crust material sinks into the mantle and stirs the entire mantle causing motion on the surface.
#21. With which of the three types of plate boundaries are following places or features associated: Himalayas, Aleutian Islands, Red Sea, Andes Mountains, San Andreas Fault, Iceland, Japan, Mount St. Helens?
Himalayas- Cont cont convergent. Aleutian islands- Ocean ocean Convergent. Red Sea- Cont cont divergent. Andes Mountains- Ocean cont convergent. San Andreas fault- Cont Cont divergent. Iceland- Ocean Ocean divergent. Japan- Ocean Ocean Convergent. Mount St. Helens- Ocean Cont Convergent.
#7. List the major differences between P and S waves.
P Waves travel through all materials but S are propagated only through solids. P waves travel faster than S waves.
#9. An earthquake measuring 7 on the Richter scale releases about __ Times more energy than an earth quake with a magnitude of 6.
#12. Contrast the physical makeup of the asthenosphere and the lithosphere.
The main difference are locations which asthenosphere is the upper layer while lithosphere is below. Physical properties for asthenosphere is composed of brittle rock and lithosphere is composed of ductile and semi-fluid rock.
#16. Contrast the movements that occur along normal and reverse faults. What type of force is indicated by each fault?
Well normal faults the haginging wall block slides down along the fault surface. In reverse fault movement the hainging wall block slides upward along the flat surface.
#23. What is passive continental margin? Give an example. Give an example of an active continental margin.
North America is a Passive . South america represents a Active. A passive is the zone of the ocean floor that separates the thin oceanic crust from thick contintal crust.
#3. Why is a volcano fed by highly viscous magma likely to be a greater threat than a volcano supplied with very fluid magma?
Well highly viscous magma are more explosive while very fluid magma is less explosive because of the pressurized gases escape with relative ease.
#5. List the main gases released during a volcanic eruption. What role do gases play in volcanic eruptions?
The main gases are water vapor, carbon dioxide, nitrogen, sulfur compounds and small amounts of chlorine, hydrogen, and argon. And they role play by releasing out of the eruption
#9. Compare and contrast the three main types of volcanoes (size, shape, eruptive style, and so forth).
1st shield volcanoes are among the largest on earth. There are quiet eruptions of fluid basaltic lava. Contain very little