Real-time, in-class seismic wave demonstrations using laptops

Michael WysessionWashington University

St. Louis, MO

Real-time, in-class seismic wave demonstrations using laptopsFor Mac laptops, go to: http://www.suitable.com/tools/seismac.html

For PC laptops and desktops, go to: http://qcn.stanford.edu/

For additional links, including seismometer lesson plans: http://www.iris.edu/hq/programs/education_and_outreach http://earthquake.usgs.gov/

The Stanford Quake-Catcher Network (QCN):

The QCN seismometer screen:

Step 1: Identify the 3 components

Step 1: Identify the 3 components

Step 1: Identify the 3 components

UP - DOWN

LEFT - RIGHT

FRONT - BACK

Step 2: Figure Out What It Is Measuring

Step 2: Figure Out What It Is Measuring

Step 2: Figure Out What It Is Measuring

Motions are measured as accelerations, with units of “g”It is an Accelerometer (like with car airbags)Applications: Airplanes, Rollercoasters

Step 2: Ask What Students Expect to Happen When the Laptop is Pushed

Step 2: Ask What Students Expect to Happen When the Laptop is Pushed

Probably get an answer something like this:

That’s not what they expected!!

Step 2: Ask What Students Expect to Happen When the Laptop is Pushed

Probably get an answer something like this: Displacement

Step 2: Ask What Students Expect to Happen When the Laptop is Pushed

Probably get an answer something like this: Displacement

How about Velocity?

Step 2: Ask What Students Expect to Happen When the Laptop is Pushed

Probably get an answer something like this: Displacement

How about Velocity?

Step 2: Ask What Students Expect to Happen When the Laptop is Pushed

Probably get an answer something like this: Displacement

How about Velocity?

How about Acceleration?

Step 2: Ask What Students Expect to Happen When the Laptop is Pushed

Probably get an answer something like this: Displacement

How about Velocity?

How about Acceleration?

Step 2: Ask What Students Expect to Happen When the Laptop is Pushed

Probably get an answer something like this: Displacement

How about Velocity?

How about Acceleration?

Yes, It really is Acceleration!

That’s not what they expected!!

Step 3: Have students try to replicate an actual 3-Component seismogram!

Sample of Real 3-Component Seismogram:

Sample 3-Component Seismac Seismogram:

Opportunity to talk about some more complex aspects, like surface wave retrograde motion and dispersion, and mode splitting

Step 4: Seismic Attenuation with Distance