Earthquake Machine Lite

Michael Hubenthal - IRIS; Larry Braile - Purdue University; John Lahr - USGS; John Taber - IRIS

Mechanical Modeling to Increase Student

Understanding of Complex Earth Systems

Guiding Question(s)

What is an earthquake?

What is the role of a model in science?

How are scientific ideas constantly changing?

Have you even been outside at night and felt nervous or frightened?

Calvin and Hobbes by Bill Watterson

Will the flashlight help us feel better here?

QuickTime™ and aCinepak decompressor

are needed to see this picture.

QuickTime™ and aCinepak decompressor

are needed to see this picture.

QuickTime™ and aTIFF (Uncompressed) decompressor

are needed to see this picture.

Answer the following question on your sticky note…

What is an Earthquake? What is an Earthquake? ??

????

????

??

??

????

????

?? ??

??

??

Cal

vin

and

Hob

bes

by B

ill W

atte

rson

B

C

EQ Machine - Lite

Top View

CRubber Band

Thin Tape Measure

Wood Block w/ SandpaperTape Measure

Sandpaper

Wood Block Guide

B

C

EQ Machine - Lite

Top View

Bulk of the Plate

Edge of the Plate

Elastic Properties of Earth Materials Plate has Constant

Velocity Here of 1cm/year

Seismic MomentMo = fault length x fault width x displacement x rigidity

Moment Magnitude = Mw = log Mo/1.5 – 10.7

Seismic MomentMo = fault length x fault width x displacement x rigidity

Visualizing magnitude with the model

B

Moment Magnitude = Mw = log Mo/1.5 – 10.7

Distant forces cause a gradual build up of stress in the earth over tens or hundreds or thousands of years, slowly distorting the earth underneath our feet. Eventually, a pre-existing weakness in the earth--called a fault or a fault zone--can not resist the strain any longer and fails catastrophically.

Elastic Rebound Theory