QUIZ 10/281. What does the Richter scale measure?2. What does the Modified Mercalli Scale measure?3. What scale is used to describe the amount of

damage caused by an earthquake?4. How many seismic stations are needed to locate

the epicenter of an earthquake?BONUS 5. Describe the effect of an earthquake with a

9.0 on the Richter Scale. 6. What is a Seismologists?

EQ HAZARDS

• Probability of an EQ is determined by historic

occurrences• Identify EQ hazards help in preventing some damage and

loss of life

Hazards• Structural Failure

• Land & Soil Failure(soil liquefaction) • Tsunami

• Landslides & Fires

Soil Liquefaction

TSUNAMI

• A large ocean wave generated by vertical motions of the seafloor

during an EQ• In deep oceans the waves travel

fast with a height of 1 m • When waves enter shallow water,

height could exceed 30 m

DECEMBER 2004 TSUNAMI

• INDIAN OCEAN EARTHQUAKE • Magnitude 9.0 EQ about 160km west of

Sumatra• A 30 m plus tall wave struck several

nations

• What do you think the Death toll was

225,000

NY Times

EQ Forecasting

Probability of an EQ occurrence based on:

1.History of EQ in an area

2.Rate at which strain builds up in the rocks

EARTHQUAKES WORLD WIDE

• 500,000 detectable earthquakes in the world each year. 100,000 of those can be felt & 100 of them cause damage

• The largest recorded earthquake in the world was a magnitude 9.5 (Mw) in Chile on May 22, 1960

• The world's deadliest recorded earthquake occurred in 1556 in central China killing an estimated 830,000 people

ANY QUESTIONS?