THE CURRICULAR BENEFITS OF A SEISMOMETER IN UTC'S GEOLOGY PROGRAM

The Geology Program (BS Geology) at the University of Tennessee at Chattanooga (UTC) has operated a Guralp CMG-6TD broadband seismometer since July of 2011.

Experiences with the seismometer have contributed enormously to the faculty’s knowledge of seismology and the extent to which seismology and whole-earth structure is taught in UTC's geology curriculum. In Physical Geology, our seismograms for select recent events are used to explain arrivals of P and S and surface waves, in classic fashion, but also to make the student’s place (UTC) relevant to the discussion. In The Dynamic Earth, an upper-level class on plate tectonics and elementary geophysics, relating expressions of seismic signals on 3 axes (vertical, N-S and E-W) to the type of wave (P, S, Rayleigh) and the direction and distance from which it came promotes an understanding of wave mechanics; picking arrivals of different phases encourages use of standard nomenclature (e.g. PP, PKiKP, SKS) and causes students to contemplate the path of the signal and conversions that occur between P and S waves; the combined use of seismic spectrograms and frequency filters demonstrate the frequency content of a signal (0.033 Hz to 50 Hz); and arrival-time calculation provides context for seismic-velocity models of Earth (e.g.IASP91, PREM, AK135).

An arrival-time calculator accommodates picking different phases based on their arrival times. Our calculator conveniently queries earthquake catalogs of the USGS for the day of interest and other criteria. Arrival times for phases from a selected earthquake are calculated using TauP (University of South Carolina, Crotwell et al.1999). Our calculator, available as a web app, was written by UTC computer science students for their capstone project and to satisfy our need for such a utility. Thus, our seismometer has benefited academic programs other than geology.

The seismometer has also contributed to awareness of the geology program. Local media commonly reference our seismic records and request our commentary on newsworthy earthquakes and seismic hazards.

Despite the urban setting of our seismometer and its installation in compacted soil, it provides excellent records of strong to great earthquakes worldwide and of light to moderate earthquakes as distant as Central America and the central and western United States.