of Earth Science |Northeastern
TO EARTH SCIENCE
Objectives #19 (October 31, 2006)
By the end of today’s class, you should be able to do the
* Describe how a seismograph works, and explain why every
monitoring station actually has three seismographs.
* Tell how P-waves and S-waves differ
in terms of velocity, the way they travel, and whether or not they can
travel through liquids.
* Explain how earthquake waves helped us learn that the outer
core is liquid, using the term S-wave shadow zone.
* Explain the significance of the P-S lag.
* Given the velocity of P-waves and S-waves, calculate how long it
would take each type to travel a given distance (e.g. 100 miles).
* Given data on the arrival times of P-waves and S-waves at several
seismic monitoring stations, calculate the P-S lag.
* Given the P-S lag for an earthquake detected at several seismic
monitoring stations, calculate how far from each station the epicenter
* Given the distance to the epicenter of an earthquake detected at
several seismic monitoring stations, locate the epicenter.
* Explain why it is necessary for you to have measurements from
at least three seismic monitoring stations to find the epicenter of an
#3: Due November
2, it requires you
to use latitude and longitude, and to
know what east and west mean in that context. If
you're uncomfortable with these concepts, you'll need to learn them on
your own before doing the homework. See p. 684-5 in your text.
© 2006 Laura L. Sanders. Last updated October