Informative Speech Assignment

Date: 02-29-16

Section:

The Road to Shaking

Specific Purpose Statement: To inform my audience about the causes and effects of earthquakes and about the “big one” that Southern California is expecting.

Central Idea: Earthquakes in Southern California are a common occurrence due to the factors that go into the cause of an earthquake, the effects and the frequent activity of our San Andreas fault.

INTRODUCTION

Seismophobia. A word that may be uncommon to some of you, but to me, I know quite well. It is defined as the overwhelming fear of earthquakes. I bear this phobia and I thought that perhaps a good way to overcome this fear was to learn about the way they work—such as their causes and effects. And that is what I am currently doing; this quarter I am taking an Earthquake class called Geology 210: Earthquakes and their effects on society. Today I am here to share with you my knowledge on earthquakes, more specifically the causes of earthquakes, the effects of earthquakes and about how extremely close the San Andreas fault is to us.

(Connective: First off, we will talk about the various causes of earthquakes.)

BODY

1. There are several reasons as to why the earth shakes, the most common causes are ones that you may never have expected.

We can first start off with how our ancestors attempted to explain the occurrence of earthquakes.

1. For example, as stated in David S. Brumbaugh’s 2010 book titled Earthquakes: Science and Society, according to Japanese folklore, “earthquakes were caused by a giant catfish beneath the ground,” and “when the catfish flailed about, the ground shook” (Brumbaugh).

2. Another belief as to why the earth shook came from India, where it was thought that the earth was held up by four elephants that stood on the back of a giant turtle, which in turn stood on a cobra and whenever any of these animals moved, the earth trembled (Brumbaugh).

Now some common causes of earthquakes could consist of the following: explosions, large landslides, the collapse of a cavern or mine, movement of magma underground, a meteorite impact or most commonly, a slip along a fault plane.

1. According to the 2011 Southern California Earthquake Center handbook

titled Putting Down Roots in Earthquake Country, authors Lucile M.

Jones and Mark Benthien state that a fault is defined as “a thin zone of

crushed rock separating blocks of the earth’s crust.”

2. When an earthquake occurs on one of these faults, the rock on one side of the fault slips alongside the other (Lucile M. Jones and Mark Benthien).

3. A slip along a fault is caused by the movement of tectonic plates and when this

occurs, it produces seismic waves which is the proper name for what we call

shaking and for what wakes us up in the middle of the night.

(Connective: Now that we have an understanding as to the causes of earthquakes, we can now delve into the effects.)

I. Earthquakes can have several effects such as the effects on our natural environment, on our buildings and structures and on our society.

One effect that an earthquake can have on our natural environment is it can cause tsunamis and landslides.

1. A tsunami is a series of waves that is produced when a body of water is dislodged by an earthquake; tsunamis can frequently result in a major catastrophe.

An effect that an earthquake can have on our buildings and structures is that they can severely damage our nuclear power plants which could lead to exposure to radioactivity and it can also damage our roads and electrical lines which can lead to the severity of our communication.

C. Another effect an earthquake can have, is on our society which can involve an

escalating death and injury toll as well as an overwhelming wave of homelessness

due to the damage done by severe shaking.

(Connective: The last thing that I wanted to inform you all on was the San Andreas fault and how we are expecting what scientists are calling “the big one.”)

II. The Southern San Andreas Fault is the closest fault to the Inland Empire and we happen to live right smack next to it.

The fault is about 800 miles long, and because of this, the biggest earthquake that can possibly be produced on this fault is around a magnitude 8.25.

1. It is important to know that the last major earthquake on the southernmost San Andreas fault occurred in 1857, more than 159 years ago and there has not been an actual rupture along the southernmost end since 1690, which was about 326 years ago.

2. On average, large earthquakes recur on the San Andreas Fault about every 150 years, so I would say that this this “big one” is approaching very soon.

3. Most of us are unknown to the fact that an earthquake of this size can be very

detrimental to our community.

So that is why in 2008, the California Geological Survey and Southern California Earthquake Center teamed up to create an earthquake scenario called ‘The California Shakeout Scenario’, in which a hypothetical 7.8M earthquake occurred along the southernmost San Andreas fault.

3. The results were devastating and it opened many eyes as to what the effect of an actual earthquake of that size could do Southern California.

4. According to the 2008 narrative titled, The ShakeOut Earthquake Scenario—A Story That Southern Californians Are Writing, written by Suzanne Perry, the results of this size of an earthquake would include roughly 2,000 deaths, 50,000 injuries, 270,000 homeless and over $200 billion in damages.

The goal of the 2008 Shakeout was to increase resiliency of earthquakes and that is what it did, because more than half of our state has signed up on the Southern California Earthquake Center website to participate in upcoming scenarios.

(Connective: In short, the small earthquakes that occur on the San Andreas Fault and that we experience, are nothing compared to what we are expecting in our future, more specifically, in the next 30 years.)

CONCLUSION

In closing, taking this class on earthquakes has seemingly helped me with my seismophobia and I hope that today I have helped some of you that also share the same fear, by sharing with you the causes and effects of earthquakes and about the mysterious, yet inevitable ‘big one’ of the San Andreas fault. I would like to leave you with this quote by Suzanne Perry in the 2008 narrative titled, The ShakeOut Earthquake Scenario—A Story That Southern Californians Are Writing, “The question is not if but when southern California will be hit by a major earthquake—one so damaging that it will permanently change lives and livelihoods in the region.”

References

Brumbaugh, D. S. Earthquakes: Science and Society. Ed. Nicole Folchetti. 2nd Ed. Upper

Saddle River: Pearson Education, 2010. Print.

Jones, L. M., and Benthien, M. Putting Down Roots in Earthquake Country.

California: U of Southern California P, 2011. Print.

Perry, S., et al. The ShakeOut Earthquake Scenario—A Story That Southern Californians Are

Writing. Reston: U.S. Geological Survey, 2008. PDF file.

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