OPENING QUESTIONS:
What is the relationship between p & s wave arrival time and distance to an earthquake epicenter?
What is the magnitude of an earthquake defined to be?
How does magnitude fit into our discussion of earthquake waves?
LEARNING TARGET:
1) I will work with my team to analyze & summarize last Friday's Reading during today's class.
2) I will practice calculating the epicenter of an earthquake using seismograph data during today's class
WORDS O' THE DAY:
- Primary (p) waves - Travel through all types of material and arrive first.
- Secondary (s) waves - Only travel through solid rock (not liquids of any sort) and arrive later
- Surface waves - Only travel along the surface of the earth-- they arrive LAST but are most destructive
- focus - The location of an earthquake inside the Earth
- epicenter - The point on the Earth's Surface directly above an earthquake
WORK O' THE DAY:
We have a BLOCK SCHEDULE today
Please work with your team to write down 2 - 3 word terms/phrases/ideas that you gleaned from The Really Big One. Please take a sharpie and write clearly in large letters (we'll put these on the board in a moment). Each person should *easily* be able to recall 1/2 dozen ideas (at least) from the reading.
When you're done, please sort those strips in ANY particular order that you agree on.
Each person will take turns leading the conversation
Hint: There should be LOTS
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You'll very likely need me to print for you today. Please copy any image you need to your Google drive and place the link HERE and I'll print it for you!
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Remember these?
Here's a *varsity* level assignment. The following images are from seismographic data taken at three different places around the world.
Some aspects of those graphs make your life a *WHOLE* lot easier. Others, well, not so much.
Your job is to use whatever tools you have at your disposal to address our activity question:
Where did this earthquake occur?
Now let's work to calculate the magnitude of that earthquake event using a fairly rough approach. The following to graphics are 'nomograms' that are created using richter scale data.
The problem with Richter data is that it is HUGELY based on Southern California data, which, not at all coincidentally was where Richter lived.
There is no one-size-fits-all nomogram because the geological characteristics of each part of the Earth's crust are different.
However, since we are NOT seismologists, we'll give a whirl with the Richter Nomogram:
If you're feeling rather *mathy* you can always do this:
Where:
-
ML = Local magnitude
-
= Maximum amplitude of seismic waves (in millimeters)
- = Epicentral distance (in kilometers)
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