Locating an epicenter

Even classes, due 3/1/11
Odd classes, due 3/2/11

Finish the Locating the epicenter class work if you did not finish in class.  The figures mentioned are in your text book.

Problem:  Determine the epicenter location and the time of occurrence of an actual earthquake, using the travel time of P and S waves recorded at three seismic stations.

Materials:  figure handout and map, drafting compass (or string and tack), metric ruler

Procedure:

1.       The seismogram in Figure 19-8 shows the arrival time of the first P-wave at 10h, 50min, 32s GMT.  Estimate the arrival time of the first S-wave to the nearest tenth of a minute.

2.       Subtract this S-wave time from the initial P-wave time. What is the P-S separation on the seismogram, in minutes and tenth of minutes?  Enter this value in the Data table for the Berkeley seismic station.

3.       The P-S separation observed on two other seismogram, also listed on the table.  Use the travel-time curves in Figure 19-9 to determine the distances at which the P- and S- curves are separated by the time intervals listed in the data table under map epicenter distances.

4.       Use the scale to determine the map distance (in cm) for the epicenter distances from each seismic station and record these distances in the table.

5.       Use the compass to draw circles around each station on the map with the radius of each circle equal to the map distance in cm, for that station.’

6.       Mark the point of intersection.  This is the epicenter of the earthquake.

7.       Determine the time of occurrence of the earthquake by reading the P-wave travel time from Figure 19-9 for the epicentral distance for Berkeley.  Subtract this from the initial P- wave arrival time at Berkeley, which was 10h, 50mom.  Express this time in hours, minutes and seconds.

AND
Read 511-515 1) according to the reading how do tsunamis occur?  2) Why is the term tidal wave incorrect for describing tsunamis?  3)  do the using math problem on p 513

ND EQ 1

Even classes due 2/18/11

Read 505-510 and describe how seismic waves have provided evidence of the Earth's interior structure and composition.

PERIOD 1, 3, 4 & 6; none of you pointed out that the Mercalli and Richter scales were not part of the previous hw reading.  And I erred by assigning as DSW describing these scales instead of assigning the description as hw.  I will not grade you down for the DSW, you do need to answer the above hw based on the previous HW read and be sure to read p505-510.


Odd classes due 2/28/11
PERIOD 5; a student noted that the DSW on Describing the Richter and Mercalli scales was not in the previous hw reading selection.  In 5th period your DSW was to describe seismic waves as evidential support for Earth's interior structure and composition.  You are to do the reading of p 505-510 and describe the difference between the Richter and Mercalli scales; you do not need to copy the scales.

More deformation

both classes use the text book to diagram the reverse, normal and strike slip fault into you notebooks, label the diagrams. 

NOTE:  earthquake disaster experts need to know the type of fault that causes their EQ and other types of fault beyond the three listed here.

Due:  even 2/16/11; odd 2/17/11

EMP revisits

Even classes your revisits are due by 2/15/11 office hours, come to my room at 3PM.

Odd classes your revisits are due by 2/17/11 in class or at lunch office hours.

Missing WCPs must be turned in before 2/15 to avoid 0 points and strike on academic honesty policy.  Come to office hours if you need more feedback on poster revisits.  Students must contribute to poster revisits to earn more points.

Plate deformation 2

Even classes due on 2/14/11

read 495-504 and make sure you have diagrams of strains and folds in your notebook.

Deformation of plate read

Odd classes, oops and even now

read p. 84-91

Study for EM test

Even classes test Tuesday & Odd classes test Wednesday.

All notebooks considered approved if the notes are in your own handwriting & no loose papers in notebook.

I have advised making the final draft of the Density of Mineral lab as a homeowrk assignment versus completing it (question #4) during the test, see earlier post.

Density of Mineral accepted values and FD info for EM test question

Students have conducted data collection for the lab in class and they have been told they may complete the final draft at home (recommended) or they may do the FD in class during the EM Test (four questions timed at 60 minutes total).

Lab Final Draft requirements (EM test question # 4)

Data Table:  make a ruled data table to record your measurements and observations.


Analysis:

1. Show your calculations for the density of each mineral sample
2. Make a bar graph that compares your calculated density for each mineral sample to the accepted density of the mineral samples provided by your teacher.  Graph the mineral samples from least dense to most dense.
3. Make a diagram that shows the crust, mantle, outer core and inner core of the Earth and label where the minerals identifed in your lab would be found based on Density alone.

Conclusion:  The following are prompts to help you write a conclusion.  Write you conclusion using complete sentences and the rubric.

Frame work: Were you able to identify the unknown minerals by calculating their density?  If not, how did you identify the samples?  Evidence: Compare the accuracy of your density calculations to the accepted densities, USE NUMERIC EVIDENCE.  Logic:  How does your measured mineral densities compare to the class average and the actual densities?  Error:  How did error influence your calculated densities? Mention more then one source of error and its impact on data Next Step:  What could be done to improve/further investigate this experiment and why might this lab be useful to society at large?

Accepted DensityValues (mineral name, density and other properties)

Sulfur 1.96g/cm³    opaque, yellow color smells of rotten eggs

Calcite 2.7g/cm3 colorless, monoclinic crystal clear translucent – yellow-whitish opaque Calcium Carbonate

Granite 2.5-2.89 g/cm³  composite rock with smaller crystals black, grey, white and possible green or pink;  mostly silicate dioxides

Hematite  5.26g/cm³   black – reddish color, may have rust mostly iron oxides

Pyrite   5.1g/cm³ metallic yellow maybe shiny can have cubic crystals iron sulfide compounds

Galena 7.5 g/cm³  shiny metallic silver cubic crystals may have yellow sulfur or black material attached a lead sulfide

Milky quartz ~2.6 g/cm³  clear –white-rosy color, looks like rock sugar

Magnetite   5.2 g/cm³  Black/sparkles-metallic/shiny magnetic (will influence a compass needle)   iron oxides

Garnet 3.4-3.7 g/cm³  red-brown-tawny-white, glassy with conchoidal fracture

Olivine  3.3 g/cm³     green with cubic crystals a silicate

Average density by interior layer

Continental Crust:    2.7 to 3.0

Oceanic Crust:        3.0 to 3.3

Mantle (silicates):   3.3 to 5.7 (increasing with depth?)

Outer Core (liquid):  9.9 to 12.2

Inner Core (solid):  12.6 to 13.0