Storyline

for the Regional Seismicity Module

A graphical version of this storyline is available.

Module Concept: Forces that work on the Earth's crust cause the geological features that we observe and measure.

Section Concept: Forces break the Earth's crust, causing earthquakes.

Subconcept: Earthquakes are movements in the Earth's crust.
Activity #1: Rescue in Pinevale!

Subconcept: Ground motions result from shifts in the Earth's crust along breaks called faults.

Subconcept: Shifting along a fault can be modeled by movements along a plane.

Activity #2: Fault Rupture Analogies

Activity #3: Rupture Models

Subconcept: The properties of faults can be described using a variey of observations.
Activity #4: Strike and Dip

Activity #5: Revealing a Fault Plane with Aftershocks

Activity #6: Scarp Formation

Activity #7: Changing the Dimensions of the Crust

Activity #8: Oblique Slip

Activity #9: Recurrence Interval

Activity #10: Different Data, Different Rates?

Subconcept: The properties of faults in an area depend on the forces in that area.
Activity #11: How Tectonic Forces Affect Faults

Activity #12: "Find That Fault Slip!"

Activity #13: Regional Distribution of Slip

Activity #14: Partitioning Slip

Section 2: The Distribution of Earthquakes

Rates and relations in seismology

Section Concept: Earthquakes occur in clusters.

Subconcept: Earthquakes are clustered in zones where the Earth's crust has been deformed.

Subconcept: The locations of earthquakes are generally associated associated with major faults.

Activity #1: Where Do Earthquakes Happen?

Activity #2: Where Do Large Earthquakes Occur?

Subconcept: The locations of earthquakes are often associated with topographic features.
Activity #3: Does Topography Signal Earthquake Potential?

Subconcept: The locations of earthquakes vary in depth.
Activity #4: An "In-Depth" Look at Earthquake Distribution

Subconcept: Earthquakes are clustered randomly in time.

Subconcept: The rate of earthquakes varies over time.

Activity #5: Seismicity Rates

Activity #6: Is Earthquake Timing Influenced?

Activity #7: Landers Shakes Things Up

Subconcept: Past rates and patterns of seismicity can be used to calculate future probabilities of earthquakes.
Activity #8: The Gutenberg-Richter Relation

Activity #9: Aftershock Sequences

Activity #10: Recognizing Foreshocks

Activity #11: An Earthquake Deficit?

Subconcept: Seismicity rates may be related to properties of the Earth's crust.
Activity #12: Slip Rates vs. Seismicity Rates

Section 3: Measuring Earthquakes

Interpreting our observations

Section Concept: The effects of earthquakes can be recorded, measured, and analyzed.

Subconcept: Energy released by earthquakes can be recorded, measured, and analyzed.
Activity #1: Intensity Maps

Subconcept: Energy is released by earthquakes in the form of seismic waves.

Subconcept: Different types of seismic waves cause the shaking we feel.

Activity #2: Seismic Waves

Subconcept: Seismic waves are sensed by seismometers. The seismic waves are recorded as seismograms.

Subconcept: Earthquakes are located and characterized by studying seismograms.

Activity #3: Locating Earthquakes

Activity #4: The Richter Scale

Subconcept: The nature of the fault rupture that produces an earthquake can affect the amount and distribution of the energy released.