- Explain why the plastic nature of the asthenosphere and convection currents are important to the theory of plate tectonics.
In order for plates to be able to move, there must be something that permits them to flow. The asthenosphere is semi fluid, almost like a lubricating oil, that allows the movement of the tectonic plates. The mantle’s convection divides the lithosphere into plates, and moves them around the surface of earth. This is what causes the plates to move.
- Which type of plate boundary is:
- Found at mid-ocean ridges?
An underwater mountain range.
- Most often associated with forming mountain belts on continents?
Convergent plate boundaries.
- Associated with the San Andreas fault?
A continental transform fault.
- Is it better to live near a regularly active fault line or an inactive fault line? Explain.
It is better to live near an inactive fault, as those are places that we have identified as being possible locations for earthquakes. An inactive fault either does not have earthquakes, or has a very large one every several thousand years. The odds of you being in an earthquake here are much slimmer.
- Explain why volcanic activity along transform faults is relatively rare.
As no plates separate or come together, there is no crust being recycled into magma, therefore no pressure need to be relieved in the form of volcanic eruptions.
- Use a plate boundary map to explain why Japan and Indonesia should face more earthquakes than anywhere else in the world. (provide the map you used in your post)
Japan and Indonesia is situated at the intersection of several continental plates, namely the Eurasian plate, the Pacific plan, and the Philippine plate. These three are slowly grinding and moving against one another which is in turn building enormous seismic pressure.
- Use a plate boundary map and explain how plate tectonics would affect where you live.
We live in Vancouver, and as a result live on the boundary of several plates. As a result, we are a region that is expected to have many earthquakes. As it would happen, however, Vancouver has not received one in a long time suggesting that a large amount of pressure has built up over time and will be released in a very large earthquake. As a result, all houses and buildings have to be built to a very high standard in order to be able to withstand such an event.
- Use a plate boundary map and explain the relationship between the position of volcanoes, fault lines and plate movement.
As plates diverge and converge, volcanoes are created. This is due to the creation of magma from crust. As time progresses more magma is created, and more pressure as well. This pressure will have to be released eventually, through volcanic activity. This is why we see volcanoes along a fault line, and why they occur due to the movement of the plates.
- Using a plate boundary map and the population density map below,which countries are at risk of having many people affected by earthquakes and volcanic activity?
Japan and Indonesia are both very susceptible to high damages, due to their extremely high population and close proximity to volcanoes and several tectonic converging tectonic plates. The western half of North America is also a high risk, though much of it is not as populated as that of Japan, due as well to their close proximity to volcanoes and converging plates.
- Use the plate boundary map, trace out the plate boundaries on a sheet of paper. Examine the direction that the plates are moving in and sketch what the world would look like in 40 million years from now. (post your sketch)