330 likes | 493 Views
Science Shake, Rattle, and Roll. Chapter 8. What Causes Earthquakes, and How Can They Be Compared?. Earthquake is a vibration of Earth, caused by release of energy that has been stored along a fault. Most occur along tectonic plate boundaries. Think about this….
E N D
Science Shake, Rattle, and Roll Chapter 8
Earthquake is a vibration of Earth, caused by release of energy that has been stored along a fault. Most occur along tectonic plate boundaries
Think about this… • What do you think happens when an earthquake occurs? • What kind of damage could these events cause?
Guatemala, 197623,000 people killed Mexico , 1985 9,000 people killed
Earthquakes happen on faults.Who can remember the name of the fault line that runs along the length of California?
Aerial photo of the San Andreas Fault 720 miles long
Aftershock- is a shock that occurs after the first shock of the earthquake.
Richter Scale • Are numbers ranging from 1 to 10 that describes the magnitude, or strength, of an earthquake. • Named after American scientist Charles Richter • Minor earthquakes are under 4 • Major earthquakes are over 5
Focus- the point at which an earthquake begins Epicenter- the point on Earth’s surface directly above the focus of an earthquake
What do you call a scientist that studies earthquakes? Seismologists
Predicting Earthquakes • Seismologist have found that there are changes in the earth before earthquakes happen. • So, they watch instruments that measure and record these changes.
How do scientists measure the strength of an earthquake, and how can they predict future earthquakes?
Lesson 1 review • Where do earthquakes occur? • What is an earthquake? • What is the smaller earthquake like activity the happens after the first earthquake? • Who studies earthquakes? • How can you predict an earthquake?
What Happens To Earth’s crust During an Earthquake? How are Earthquakes Located and Measured?
Seismograph Seismic waves are recorded by this instrument
Pendulum seismograph measures side to side movements. Spring seismograph measures up and down movements.
Chinese created the first earthquake detectors known as Chang Heng’sseismoscope in AD132.
Tsunamis Is a seismic sea wave forms when earthquakes hit the ocean floor.
Causes of Tsunamis • Earthquakes on the sea floor • Landslides on the ocean floor • Volcanic eruptions
Tsunami Facts • Can begin at 3ft and can reach a height of 46ft when it strikes land. • Travels at 500 mph
Before After Loss of land Loss of grass/trees
Predicting Tsunamis 1946 the Tsunami Warning System was established to warn people. Two warning centers in the USA near Anchorage, Alaska and near Honolulu, Hawaii. Tsunami sensors that rest of the ocean floor. These sensors are very sensitive and can detect a change in sea level of less than millimeter.
Chapter 8 Review Vocabulary Aftershock Earthquake Fault Richter Scale Seismograph Seismologist Tsunami Magnitude Epicenter focus
Short Answer Questions: • What kind of damage could these events cause? • How do scientists measure the strength of an earthquake, and how can they predict future earthquakes • What three things Happen to Earth’s crust during an Earthquake?
Test Questions: • What is an earthquake? • Where do earthquakes occur? • What is the smaller earthquake like activity the happens after the first earthquake? • Who studies earthquakes? • How can you predict an earthquake? • What causes a tsunami? • What are the two kinds of seismographs and what kind of movements does each measure?
Bonus:1. What is this a picture of?2. What is this called?3. What country did it come from?