Measuring Measuring EarthquakesEarthquakes

By: Lily and AssulBy: Lily and Assul

EarthquakesEarthquakes

They can release a huge amount of They can release a huge amount of energy or a very little amountenergy or a very little amount

It depends on how much rock breaks It depends on how much rock breaks at a faultat a fault

It also depends on how far rocks shiftIt also depends on how far rocks shift Scientists measure earthquakes in Scientists measure earthquakes in

two ways: intensity and magnitudetwo ways: intensity and magnitude

IntensityIntensity

The measure of the amount of the The measure of the amount of the damage the quake producesdamage the quake produces

Intensity scales depend on Intensity scales depend on observation of earthquake effectsobservation of earthquake effects

The most widely used intensity scale The most widely used intensity scale is the Modified Mercalli scaleis the Modified Mercalli scale

It has intensity numbers that run from It has intensity numbers that run from I (no damage) to XII (almost total I (no damage) to XII (almost total destruction)destruction)

Intensity ScaleIntensity Scale

MagnitudeMagnitude

The amount of energy that an The amount of energy that an earthquake releasesearthquake releases

It is a more precise measure of the It is a more precise measure of the strength of an earthquake than damage strength of an earthquake than damage

Magnitude is based on measurement of Magnitude is based on measurement of the maximum motion recorded by a the maximum motion recorded by a seismograph.seismograph.

Modern seismograph systems precisely Modern seismograph systems precisely amplify and record ground motionamplify and record ground motion

Richter ScaleRichter Scale

Based on seismograph readingsBased on seismograph readings Each increase on the Richter scale is a 10 Each increase on the Richter scale is a 10

fold increase in ground shakingfold increase in ground shaking EX: During a magnitude 6 earthquake, EX: During a magnitude 6 earthquake,

the ground shakes twice as much as a the ground shakes twice as much as a magnitude 5 earthquakemagnitude 5 earthquake

Charles Richter invented the Richter scale Charles Richter invented the Richter scale to measure the magnitude of earthquakesto measure the magnitude of earthquakes

Invented in 1935Invented in 1935

Richter ScaleRichter Scale

QuizQuiz1.1. Who invented the Richter scale?Who invented the Richter scale?2.2. What two ways do scientists What two ways do scientists

measure Earthquakes? measure Earthquakes? 3.3. What is the most widely used What is the most widely used

intensity scale?intensity scale?4.4. What is the Richter scaled based What is the Richter scaled based

on?on?5.5. Why did Charles Richter invent the Why did Charles Richter invent the

Richter scale? Richter scale? 6.6. When was the Richter scale When was the Richter scale

invented?invented?

CreditsCredits

Miffilin. California Science. Badders. 2007. 152. 1/24 /14

Ammon. Measuring effects. EAS-A193. 2011. WEB 1/27/14