QUIZ 10/28 1.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?