this is what i have to have...All key elements of the assignment are covered in a substantive way.
· The student distinguishes the types of plate margins and how they move.
· The student discusses why earthquakes are common along plate margins or boundaries.
· The student discusses how the Earth moves when it does quake and shake.
· The student discusses the events that cause the Earth to quake and shake.
· The student discusses earthquake measurements.
· The student briefly describes two types of body waves an earthquake creates.
· The student provides an example of an area prone to earthquakes.
· The paper is 700 to 1,050 words in length.
I only have 431 words right now
i Have this so far: There are three fundamentally different ways in which they can interact. They can move away from each other (diverge); they can move toward each other (converge); or they can slide past each other along a long fracture.
Diverge: also called rifting or spreading centers, occur where two plates are moving apart. They can occur either in continental or oceanic crust.
In East Africa, for example, the African plate is being stretched and torn apart, creating long rift valleys. Eventually a new ocean may form in the widening rift; a modern example of this is the Red Sea. Where oceanic crust is splitting apart, the result is a midocean ridge.
Converge: occur where two plates move toward each other. This leads to different types of margins, depending on whether the boundary is between two oceanic plates, two continental plates, or one of each.
When one continent meets another continent along a convergent margin, they crumple upwards and downwards as the lithosphere thickens, in a collision zone.
Another kind of convergent margin occurs when one or both plates are oceanic. In this case, one plate will typically slide beneath the other plate, plunging into the asthenosphere, where water released from the wet rocks of the seafloor promotes formation of magma.
Transform faults: occur where two plates slide past each other, grinding and abrading their edges as they do so. The San Andreas Fault in California, it separates the northwesterly moving Pacific plate from the adjacent North American plate, which is moving toward the southwest. Transform faults are much more common in the ocean floor, where hundreds of them run perpendicular to the midocean ridges (see Figure 4.10). This causes the plates to have very complicated; jagged boundaries in which spreading centers alternate with transform faults.
Why earthquakes are common along plate margins and boundaries: Earthquakes occur along faults, where huge blocks of rock are grinding past each other. Tectonic motions produce directional pressure, which causes rocks on either side of a large fracture to move past each other. The movement is rarely smooth; usually the blocks stick because of friction, which slows their movement. Eventually, the friction is overcome and the blocks slip abruptly, releasing pent-up energy with a
Huge “snap”—an earthquake.
The actual location beneath the surface where the earthquake begins is called the focus. This should not be confused with the better-known epicenter, which is the point on Earth’s surface that lies directly over the focus. The depths of foci provide useful information about the
Characteristics of the plate margin
I am still trying to work on it more too
sci - SraJMcGin, Sunday, January 11, 2009 at 6:37pm
Although I have not read what you have written, please try the following GOOGLE Search, which may give you more information that you can use:
sci - Ms. Sue, Sunday, January 11, 2009 at 7:17pm
Dawn, you've done a fine job of covering the first two points. Now finish by discussing the last five points.