Homework 5: Chapters 22 (2-34 EVEN only) and 29 (2-32 EVEN only)
2. Earth science is an integrated science because it is necessary to understand processes that are described in other sciences (physics, chemistry, astronomy & biology).
4. Oceanic crust consists of fine-grained rock called basalt; fine grained, dense and black or dark gray in color. The continental crust is made up of granitic rock, which is lighter and less dense.
6. The asthenosphere is the same composition throughout. It is soft and flows extremely slow; so slow, in fact, that it would look like solid rock if you could see it.
8. Fossils of the Glossopteris plant were found in places that are, today, separated by large oceans. Seeds from these plants are too heavy to have been blown over by the wind. Also, fossils of Mesosaurus, a non-swimming reptile, appeared in South America and Africa and could not have evolved in the same way in these widely separated regions. These fossil findings support Wegner’s hypothesis of continental drift.
10. Wegner used rock matching as evidence to support continental drift. He found rock formations that occurred where 2 continents would meet if the ocean did not separate them. Also, he found, in some places, that mountain chains, that are separated by oceans, have patterns of folds that would be continuous if the mountain chains were brought together. Essentially, the rock matching is when they would fit like a jigsaw puzzles; torn newspaper diagram.
12. Seafloor spreading and continental drift are both caused by plate tectonics.
14. The theory of plate tectonics help us make sense of the earth’s geology. The study of the earth’s plates, how they move, etc. and helps geologist predict earthquakes, volcanic eruptions, and such; as well as explain the ones that occur without notice.
16. The two differ because it was thought that the continents move with the ocean floor not through it.
18. There are three major types of plate boundaries: divergent boundaries, convergent and transform boundaries. Divergent boundaries, plates move part and the gap fills with molten rock; this occurs mainly on the seafloor. Convergent boundaries, plates come together in a slow collision; these plates converge in 3 different ways: Oceanic-Oceanic (creates a denser ocean, Oceanic-continental (denser oceanic plates subducts into mantle, causing magna to rise), and continental-continental convergence (2 plates collide with each other and are pushed upwards).
20. The San Andreas Fault is an example of a continental transform fault.
22. Heavier material goes to the bottom and the lighter material rises to the top.
24. Recordings of seismic waves from earthquakes, was the first clue that the Earth has a liquid outer core. Seismic waves bend and reflect at the inner structure interfaces between different materials.
26. Body waves travel through the earth’s interior and surface waves travel on the surface. The body waves reveal the Earth’s inner structure because those waves travel deep inside Earth.
28. In order to locate the oldest rock on Earth, one would need to get as far away from a spreading center as possible. Rocks continually spread apart and move away from the ridges while fresh molten rock arises and forms new rock at the ridge. Further the rock spreads, the older they get.
30. The second law of thermodynamics states that heat always flows from warmer to cooler places; this is why heat moves from the Earth’s interior to its surface.
32. Convection currents occur when temperatures at the bottom are hotter than at the top, like in a boiling pot of water. Plates sit on the asthenosphere, a very hot layer, that carries the lithosphere of the earth.
33. These deep ocean trenches are occupied by extremophiles, that can…