} CAS: Teachers - Plotting Earthquakes

Teachers > Lessons & Kits > Lesson Plans > Anytime Lesson Plan: Plotting Earthquakes

# Anytime Lesson Plan: Plotting Earthquakes

### Abstract

In this activity, students will learn how to plot earthquakes on a map by exploring recent earthquake activity in California and Nevada.

### Objectives

In this activity, students will:

1. learn how to plot earthquakes on a map,
2. explore recent earthquake activity in California and Nevada.

### Materials

• California Map (1 per 4 – 6 students, provided)
• pencils
• rulers
• Map of Fault Lines (provided)
• printout of recent earthquakes in California (provided, or you can use your own)

### Vocabulary

• crust: the outermost and thinnest of Earth’s layers.  The crust is mainly composed of igneous and metamorphic rocks and is divided into plates that move very, very slowly.
• earthquake: a sudden rapid shaking of the ground caused by a rapid release of energy along faults
• epicenter: the point on earth’s surface that is vertically above the focus (hypocenter) of an earthquake
• fault: a break or fracture in a rock mass across which movement has occurred
• longitude:  part of a grid used for describing positions on Earth’s surface, consisting of half circles joining at the poles. A measurement, in degrees, of a place's distance east or west of the prime meridian, which runs through Greenwich, England
• latitude:  part of a grid used for describing positions on Earth’s surface, consisting of parallel circles. A measurement, in degrees, of a place's distance north or south of the equator
• mantle: the thick layer of dense, rocky matter found below the Earth’s crust and surrounding the Earth’s core
• plate tectonics:  the theory that explains the movement and interactions of plates, which are segments of the Earth’s crust.  The plates move slowly and continuously, and their interactions generate earthquakes, volcanoes, and mountains.
• pressure: the application of continuous force on an object

## Preparation

1. Print out California Maps (1 per group)
2. Obtain list of recent earthquakes.  You can use the one provided, or visit USGS for up to date information on recent earthquakes.

## Introduction

Tell students that earthquakes are generally caused by the interaction of the plates on Earth’s surface.  Earth’s crust is fractured into irregular plates that are constantly in motion.  These plates can interact in three main ways: they collide, diverge, and slide against each other.  Where plates converge, or come together, mountains and volcanoes are formed. Where plates diverge, or move apart, new crust is created by rising magma.  Finally, some plates grind past each other, like here in California where the Pacific and North American plates move in opposite directions.

Ninety percent of the world’s earthquakes occur in narrow zones along plate boundaries.  As plates move relative to each other, they build up strain where the plates meet. When the rock finally moves, energy is released in the form of seismic waves, i.e. an earthquake. Scientists can use seismic data to determine where the waves originated and can then use that data to map the locations of the plates – which is what students will do in this activity.

## Procedure

1. Ask students what causes earthquakes? (movement of plates that buildup pressure that is then suddenly released in the forms of seismic waves)
2. Ask students about types of waves and how they are similar and different. (For example, light and sound travel at different speeds. When you drop a pebble in the water the waves radiate out in all directions but when you send a wave through a rope is only travels in one direction )
3. If you have a slinky you can model how waves move through the earth by stretching it out and sending shock waves through the coils to a person on the other end.
4. Divide the class into groups of 4-6 students and hand out the map of California to each group.
5. Once the students have an understanding of earthquakes, show them the map of California and discuss latitude and longitude lines. Each place on earth has a specific value associated with it. The latitudinal and longitudinal lines are similar to addresses that we use for the mail, only these addresses can be found by anyone, anywhere.
6. Working in their groups, practice using latitudinal and longitudinal lines by determining where the major cities on the maps are located. Use rulers to help students line up the text of the lines with the place on the map.
7. Once students have the hang of it, start plotting the recent earthquake epicenters. Either give each group a list of earthquakes or write the latitude and longitude on the board.
8. After students have plotted the epicenters, have them predict where the fault lines in California are.
9. Once their predictions have been made, show them the map of the fault lines in California.

### Extensions

• Pair this activity with one of the Academy’s earthquake preparedness lessons; What Happens in an Earthquake? and Earthquake Preparedness: Thinking Ahead
• Play “Quake Quiz SF” (http://quakequizsf.org/).  Players are given 6 different locations in which an earthquake might take place and then are asked what they should do in each situation.
• Connect this lesson to the Earthquake exhibit.  If you will be bringing your class to the Academy, you can reinforce what they have learned in this activity throughout the exhibit.  Have students find the map of the faults of the Bay Area to review what the faults are and how earthquakes occur.

### Resources

Online

Books

• Blobaum, C. 1999. Geology Rocks!: 50 Hands-On Activities to Explore the Earth. Charlotte, VT, Williamson Publishing Co.
• Skinner, B. 2004. Dynamic Earth. Hoboken: John Wiley & Sons, Inc: UK.

Books in Spanish

• Rosinsky, N.M. (2003) Las Rocas, Duras, Blandas, Lisas, y Ásperas. Mankato, MN, Picture Window Books

### Earth Sciences

• 5a. Students know some changes in the Earth are due to slow processes, such as erosion, and some changes are due to rapid processes, such as landslides, volcanic eruptions, and earthquakes.

### Investigation and Experimentation

• 6a. Differentiate observation from inference (interpretation) and know scientists' explanations come partly from what they observe and partly from how they interpret their observations.

### History and Social Science

• 4.1.1. Explain and use the coordinate grid system of latitude and longitude to determine the absolute locations of places in California and on Earth.

### Earth Sciences

• 1a. Students know evidence of plate tectonics is derived from the fit of the continents; the location of earthquakes, volcanoes, and midocean ridges; and the distribution of fossils, rock types, and ancient climatic zones.
• 1d. Students know that earthquakes are sudden motions along breaks in the crust called faults and that volcanoes and fissures are locations where magma reaches the surface.
• 1e. Students know major geologic events, such as earthquakes, volcanic eruptions, and mountain building, result from plate motions.

### Background

The Earth, our rocky planet, is very active. Earthquakes happen every day. As you are reading this volcanoes are erupting and earthquakes are shaking, mountains are being pushed up and are being worn down, rivers are carrying sand and mud to the sea and huge sections of the Earth's crust called tectonic plates are slowly moving - about as fast as your fingernails grow.

The earth’s crust is composed of 7 major tectonic plates and many minor plates that move around the earth due to cycles of heating and cooling in the mantle (the pliable layer beneath the crust). These plates interact with each other in three separate ways; they can collide, diverge, or slide past each other. When these plate movements happen, we get earthquakes. In California the North American Plate is colliding and sliding past the Pacific Ocean Plate and this causes earthquakes. Sometimes there are catastrophic earthquakes, but more often they are smaller movements. In this activity students will plot recent earthquakes on a map.