# GP130 - Strong Motion Seismology

GP130 is an upper division course originally designed to illustrate the role that seismology plays in the mitigation of seismic hazard. Historically it has been taught with an engineering focus, and in fact the majority of students come from the various civil engineering specialties. GP130 is taught at a fairly rigorous level. Mathematics 50A or 54 are prerequisite courses. Students taking this course should be familiar with calculus, ordinary and partial differential equations, and integral transform methods. It is assumed that the students have not had any exposure to introductory geology, geophysics or seismology although such introductory courses are recommended.

The general course outline covers the aspects of geology and seismology which are relevant to the study and mitigation of seismic hazards. The goal of the course is to provide the students with an understanding of basic seismology and an introduction to the research that eventually leads to seismic design code changes. For example the attenuation of seismic energy with distance is a significant subject of GP130. Here students are introduced to the concepts of geometrical spreading, anelastic attenuation, scattering, empirical attenuation studies, and the influence of crustal structure on the focusing and defocusing of seismic energy. Other topics which receive considerable treatment in GP130 include, spectral analysis methods, seismic source theory, elastic wave propagation and various case histories of recent notable earthquakes such as the 1992 Landers, 1994 Northridge and 1995 Kobe events. Other topics that are covered in GP130 include:

Review of plate tectonics, global seismicity, earth structure
California geology, history of California seismicity
Common fault types
Seismic instrumentation (theoretical development and application)
Analysis of seismograms

earthquake location
earthquake magnitude
Seismic source theory
elastic rebound theory
seismic moment, seismic energy, stress drop
source scaling relationships
source spectrum
radiation pattern - different fault types
directivity
distributed slip
asperities and barriers
case studies
Elastic wave propagation
review of continuum mechanics
elastic wave equation
boundary value problems
refraction, reflection (moho), diffraction
surface waves
free surface amplification (focusing, impedance contrast)
site response
new directions - two and three-dimensional earth structures,
basins and site response
Intensity
Secondary seismic hazards
Earthquake prediction
Near realtime analysis and early warning systems