Measuring Earthquakes By: Lily and Assul

Earthquakes  They can release a huge amount of energy or a very little amount  It depends on how much rock breaks at a fault  It also depends on how far rocks shift  Scientists measure earthquakes in two ways: intensity and magnitude

Intensity  The measure of the amount of the damage the quake produces  Intensity scales depend on observation of earthquake effects  The most widely used intensity scale is the Modified Mercalli scale  It has intensity numbers that run from I (no damage) to XII (almost total destruction)

Intensity Scale

Magnitude  The amount of energy that an earthquake releases  It is a more precise measure of the strength of an earthquake than damage  Magnitude is based on measurement of the maximum motion recorded by a seismograph.  Modern seismograph systems precisely amplify and record ground motion

Richter Scale  Based on seismograph readings  Each increase on the Richter scale is a 10 fold increase in ground shaking  EX: During a magnitude 6 earthquake, the ground shakes twice as much as a magnitude 5 earthquake  Charles Richter invented the Richter scale to measure the magnitude of earthquakes  Invented in 1935

Richter Scale

Quiz  Who invented the Richter scale?  What two ways do scientists measure Earthquakes?  What is the most widely used intensity scale?  What is the Richter scaled based on?  Why did Charles Richter invent the Richter scale?  When was the Richter scale invented?

Credits Miffilin. California Science. Badders /24 /14 Ammon. Measuring effects. EAS-A WEB 1/27/14