Finding the Moho

Stephen K. Boss

Universityi of Arkansas

This lab is designed for a first course in geophysics (undergraduate) for geology majors (mainly seniors).
Designed for a geophysics course

Students must have mastered fundamental principles of seismic refraction and have some familiarity with seismology (to the level of understanding that different seismic phases exist and refract through Earth's interior); they must also know that seismograms are records of earthquakes arriving at seismic stations. Students must be able to plot data in spreadsheet software and graphically display these data. Students must know a bit about linear regression (at least to the level of adding a trend line to data in Excel and interpreting the associated linear equation).

This lab follows is offered toward the end of the first third of the course (approximately 5 weeks into semester) and follows previous labs related to seismic refraction. Students should have some familiarity with refraction phenomena and spreadsheet software prior to attempting this lab.

determining time-distance relations from seismograms; plotting first-arrival data from seismograms; attempting to recognize first-arriving energy from different seismic phases.

students must be able to analyze data to determine that more than one seismic phase is present; students must be able to determine time-distance relations for different phases; students must be able to analyze refraction profile data to determine depth to refracting horizon.

Please refer to attached document.
Uses online and/or real-time data
Addresses student fear of quantitative aspect and/or inadequate quantitative skills

All students use the same data, so all plotted data and results should be equivalent allowing for some measurement and round-off error. Depth to the Moho should be determined within a few kilometers of known depth for this region.

Please refer to attached document.