assignment 10/27 1. 1. copy down the notes, cornell style. i have put stars next to the notes which...
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Assignment 10/27Assignment 10/271. Copy down the notes, cornell
style. I have put stars next to the notes which are usually highlighted.
2. Answer the Concept Checks on a separate sheet of paper to be turned in when you return your notes.
3. After you finish taking notes, begin working on the Project at the end of the notes. You will have time the next class to FINISH the project.
Destruction from Destruction from EarthquakesEarthquakes
Chapter 8, Section 3Chapter 8, Section 3
Seismic VibrationsSeismic Vibrations The damage to buildings and other The damage to buildings and other
structures from earthquakes depends on structures from earthquakes depends on several factors. several factors. The three factors include The three factors include the intensity and duration of the vibrations, the intensity and duration of the vibrations, the nature of the material on which the the nature of the material on which the structure is built, and the design of the structure is built, and the design of the structure.structure.
Engineers have learned that unreinforced Engineers have learned that unreinforced stone or brick buildings are the most stone or brick buildings are the most serious safety threats during earthquakesserious safety threats during earthquakes
Liquefaction –Liquefaction – loosely consolidated loosely consolidated sediments are saturated with water and sediments are saturated with water and turned into a liquid that is not able to turned into a liquid that is not able to support buildingssupport buildings
Seismic DamageSeismic DamageLiquefaction – Niigata, Japan 1964
Ground Shaking – Loma Prieta, CA 1989
Concept CheckConcept Check
When does liquefaction occur?When does liquefaction occur?
TsunamisTsunamis Tsunamis –Tsunamis – A large water wave caused by A large water wave caused by
seismic waves seismic waves A tsunami triggered by an earthquake A tsunami triggered by an earthquake
occurs where a slab of the ocean floor is occurs where a slab of the ocean floor is displaced vertically along a faultdisplaced vertically along a fault
A tsunami also can occur when the A tsunami also can occur when the vibration of a quake sets an underwater vibration of a quake sets an underwater landslide into motionlandslide into motion
A tsunami can travel across the ocean at a A tsunami can travel across the ocean at a speed of 500-950 km/hrspeed of 500-950 km/hr
When the wave enters shallow coastal When the wave enters shallow coastal waters, it will slow down and begin piling waters, it will slow down and begin piling on top of itself to reach a height on top of itself to reach a height sometimes greater than 30 meterssometimes greater than 30 meters
TsunamisTsunamis
Tsunami Travel Time to Tsunami Travel Time to HonoluluHonolulu
Indonesia Tsunami – 2004Indonesia Tsunami – 2004
Indonesia Tsunami – 2004Indonesia Tsunami – 2004
Concept CheckConcept Check
At what point does the tsunami gain At what point does the tsunami gain the most height?the most height?
Other DangersOther Dangers The greatest damage to structures is The greatest damage to structures is
from landslides and ground from landslides and ground subsidence, or the sinking of the subsidence, or the sinking of the ground triggered by vibrationsground triggered by vibrations
The violent shaking can cause water The violent shaking can cause water and gas lines to ruptureand gas lines to rupture
Fire is also a threat, as witnessed by Fire is also a threat, as witnessed by the large-scale destruction of San the large-scale destruction of San Francisco when their gas and electric Francisco when their gas and electric lines were cut along with the water lines were cut along with the water lines needed to put out the fireslines needed to put out the fires
Other DangersOther Dangers
Fire – San Francisco, 1906
Landslide – Turnnagin Heights, Alaska, 1964
Predicting EarthquakesPredicting Earthquakes The goal of short-range prediction is to The goal of short-range prediction is to
provide an early warning of the location provide an early warning of the location and magnitude of a large earthquakeand magnitude of a large earthquake
Methods for short-range predictions of Methods for short-range predictions of earthquakes have NOT been successfulearthquakes have NOT been successful
Long-range predictions give the probability Long-range predictions give the probability of a certain magnitude earthquake of a certain magnitude earthquake occurring within 30 to 100-plus yearsoccurring within 30 to 100-plus years
Seismic gap – Seismic gap – an area along a fault where an area along a fault where there has not been any earthquake activity there has not been any earthquake activity for a long period of timefor a long period of time
Scientists don’t yet understand enough Scientists don’t yet understand enough about how and where earthquakes will about how and where earthquakes will occur to make accurate long-term occur to make accurate long-term predictionspredictions
Probability of Earthquakes Probability of Earthquakes Along the San Andreas FaultAlong the San Andreas Fault
Shaking Hazard for Southern Shaking Hazard for Southern CaliforniaCalifornia