The magnitude M of an earthquake is given. a. Find the earthquake intensity I in terms of the zero-level earthquake intensity lo. b. Find the energy released by the earthquake. M = 7.3

On the Richter scale, a magnitude 7.0 earthquake is how many times more powerful than a magnitude 6.0 earthquake? (21.5) (a) 1 (b) 25 (c) 31 (d) 100

Tectonic plates are large segments of Earth’s mist that move slowly. Suppose one such plate has an average speed of 4.0 cm/yr. (a) What distance does it move in 1.0 s at this speed? (b) What is its speed in kilometers pet million years?

If you wanted to live where the chances of a destructive earthquake were small, would you pick a location near a fault zone, near a mid ocean ridge, near a subduction zone, or on a volcanic island such as Hawaii? What are the relative risks of earthquakes at each of these locations?

Over the entire Earth, there are 60,000 km of active rift zones, with average separation rates of 5 m/ century. How much area of new ocean crust is created each year over the entire planet? (This area is approximately equal to the amount of ocean crust that is subducted since the total area of the oceans remains about the same.)

(a) About how many microorganisms are found in the human intestinal tract? (A typical bacterial length scale is one micron = 106 m. Estimate the intestinal volume and assume bacteria occupy one hundredth of it.) (b) Discuss your answer to part (a). Are these bacteria beneficial, dangerous, or neutral? What functions could they serve?

(a) Suppose that a person has an average heart rate of 72.0 beats/min. How many beats does he or she have in 2.0 y? (b) In 2.00 y? (c) In 2.000 y?

The average life expectancy in Japan is 81 years. What is this time in SI units?

What are the standard time and date at (40N, 118W) when the standard time at (35N, 80W) is 6 p.m. on October 8?

From Hawaii to the bend in the Hawaiian-Emperor chain is about 4000 km. Use the speed of Pacific plate motion given in Problem 7 to estimate how long ago the direction of plate motion changed. (Note: It may not be a coincidence that the San Andreas fault became active in what is now Southern California at about the same time.) 7. The Hawaiian-Emperor chain of undersea volcanoes is about 7500 km long, and the Pacific plate is moving 9.2 cm a year. How old is the oldest detectable volcano in the chain? What has happened to older volcanoes in the chain?