代写ESS17-Catastrophes Discussion 1 Disaster Forecasts and Recurrence Interval代写留学生Matlab语言程序

ESS17-Catastrophes

Discussion 1

Disaster Forecasts and Recurrence Interval

For your introductory week, you will discuss the recurrence intervals of catastrophes and attempt to make your own disaster forecast. Please feel free to work in groups, but your work that you turn in at the end of the day should be your own.

Part I: The following table records all Earthquakes above a magnitude of 5.0 that have occurred in Irvine since the year 1900. While many smaller earthquakes occur on a daily basis, large ones are less frequent. Fill in the table and use it to help you answer the questions that follow.

Year	Earthquake Magnitude	Rank (m)	Recurrence Interval (T) (T=n/m))	Annual chance (1/T) [%]
1901	5.1
1916	5.7
1926	5.2
1955	7.1
1963	5.8
1980	6.6
1988	5.3
1999	6.4
2015	5.9
Rank (m) = largest event (1) to smallest event (9) (n) = number of years in record =youngest date- oldest date + 1

1. What is the recurrence interval of a magnitude 7 earthquake for the region?

2. What is the approximate chance that a magnitude 6.5 earthquake will occur this year?

3. What do you think is meant by the term “100 year flood?”

4. What is the difference between a forecast and a prediction?

Part II: From a catastrophes perspective (and Ben Affleck), an asteroid impact would be an Armageddon-type event. In actuality, however, Earth is constantly being bombarded by small impact events. Use the table below to answer the questions that follow.

In the first graph below, plot the size (diameter) of the asteroid vs. the impact interval using the numbers reported in the table (actual size and number of years). In the second graph, plot the same information, but this time using a log scale. It’s ok to use a calculator (your phone will do) for the log scale, but if you are confused about logarithms then now is the time to ask your TA!

1. When might you want to use a log-scale graph? Why?

2. If the size of the dinosaur-impacting asteroid was 10km wide, and it occurred 65 million years ago, what is the % chance that an asteroid that size will hit this year?