Section 19 3 Measuring and Locating Earthquakes 8
- Slides: 12
Section 19. 3 – Measuring and Locating Earthquakes 8 th Grade Earth and Space Science Class Notes
Earthquake Magnitude and Intensity • Richter scale – measures the magnitude (energy) of an earthquake. – Determined by the amplitude (height) of the seismic wave – Each number on the Richter scale corresponds to an amplitude increase of 10 x – Each increase in magnitude corresponds to a 32 x increase in energy
Earthquake Magnitude and Intensity • Moment magnitude – measures the energy released by an earthquake, taking into account the size of the fault rupture, the amount of movement along the fault, and the rocks’ stiffness • Used most often by seismologists • This is what is often reported by news outlets
Earthquake Magnitude and Intensity
Earthquake Magnitude and Intensity • Modified Mercalli – measures the intensity of the earthquake by the type and amount of damage it causes
Earthquake Intensity • The intensity of an earthquake depends primarily on the amplitude of the surface waves generated. • Intensity is highest closest to the epicenter and decreases as you travel further from the epicenter.
Depth of Focus • Earthquakes are classified as shallow, intermediate, or deep, depending on the location of the focus. • Shallow-focus earthquakes are the most damaging.
Locating an Earthquake • An earthquake’s epicenter’s location, as well as the time of occurrence, can be determined using seismograms and travel-time curves.
Locating an Earthquake – Distance to an Earthquake • The distance to an earthquake’s epicenter can be determined by measuring the separation on any seismogram and identifying that same separation time on the travel-time graph.
Locating an Earthquake – Distance to an Earthquake • Scientists identify the seismic stations on a map, and draw a circle with the radius of distance to the epicenter from each station. • The point where all the circles intersect is the epicenter.
Locating an Earthquake – Time of an Earthquake • Seismologists can use a seismogram to gain information about the exact time that an earthquake occurred at the focus. • The time can be determined by using a table similar to a travel-time graph.
Seismic Belts • The majority of the world’s earthquakes occur along narrow seismic belts that separate large regions with little or no seismic activity. • The locations of most earthquakes correspond closely with tectonic plate boundaries.
- Chapter 8 section 2 earthquake measurement answer key
- In what section of earth do earthquakes happen
- Types of jig and fixture
- Recruitment is the process of locating identifying and
- Close packing
- Chapter 8 earthquakes and volcanoes
- Chapter 8 earthquakes and earth's interior
- Chapter 8 earthquakes and earth's interior answer key
- Locating places on earth
- What are the rules in the selection of delta?
- Inductive clamp locating method
- Earth science part d
- Four ways of locating the ethical in you