J.B. Macelwane, SJ, wrote the first seismology textbook in America, "Introduction to Theoretical Seismology". Dr. Hanks has authored dozens of scholarly papers in strong-motion seismology and tectonic geomorphology. Like the present day Geomorphology, Seismology, Topology etc. They can be measured in numerous different ways, including surface heat flow, petrology, and seismology. A seismologist is a scientist who does research in seismology. It is one of a number of seismic sources used in reflection seismology. It is the principal agency responsible for meteorological observations, weather forecasting and seismology. In reflection seismology, an array of seismometers image sub-surface features. Ground shaking is usually measured as peak ground acceleration (PGA) in seismology and earthquake engineering. Reflection seismology is similar to sonar and echolocation. Engineering seismology is the study and application of seismology for engineering purposes. The concept of deconvolution had an early application in reflection seismology. There are two principal components of engineering seismology. The oscillations that have been successfully utilized for seismology are essentially adiabatic. Shear waves in solids usually travel at different speeds, as exhibited in seismology.