Part 1 The motion for three cities in California are presented in Table 1. Table
ID: 232053 • Letter: P
Question
Part 1
The motion for three cities in California are presented in Table 1.
Table 1
Please explain why the two cities farthest (500 miles) apart are moving at a similar speed and direction, while the two cities closest together (140 miles) are moving at a very different speed and direction. In your response clearly indicate the tectonic setting for this area.
Part 2
The motion for two locations near Seattle Washington are presented in Table 2.
Table 2
250 miles West of Seattle
Please explain why the two locations are moving at a very different speed and direction. In your response clearly indicate the tectonic setting for this area.
Location Azimuth(cw from N) Speed
(mm/yr) Twentynine Palms 219.61 16.78 San Francisco 215.66 18.37 Los Angeles 297.63 47.72
Explanation / Answer
Plate tectonics describes the motions of the 15 to 20 large rigid and brittle tectonic plates into which the Earth's outermost layer (called the "lithosphere") is broken. The lithosphere of the earth is divided into a small number of plates which float on and travel independently over the asthenosphere, which lies over the mantle.
The relative and absolute velocities can be calculated using the Internet program but the coordinates are crucial, for very different results may be obtained if the coordinates are not correct. Due to various activities on different points on and below the earth's surface, the movement of one plate is not uniform. One plate can have many velocities depending upon the location. I suppose there's no agreeable data because there is probably no real efficient method of measuring all the tectonic plates on earth. There are many factors involved with plate tectonics; they don't just move in one path, but they individually take many different paths. They interact with each other and affect the motions by applying various types of stress and pressure, etc. at different points on the earth. Also, the earth is constantly changing and so there is no exact number to reflect the velocities of the plate tectonics.
AS we know the earth is divided into number of major and minor plates.