Abstract The physical properties of earth materials that control mechanical wave propagation are numerous. A short list would include mineralogy, lithology, porosity, pore fluid, fractures, density, and permeability, as well as large-scale structure and stratigraphy. All of these properties can and do vary from point to point in the earth. To make progress in seismic simulation and processing, a mathematical model is used to approximate wave propagation and understand phenomena. This model can assume the earth is a fluid, a solid, or a porous solid. As with many other topics, we develop the theory of seismic waves in progression from the simplest useful setting to complex models that exhibit most of the wave effects seen in real data.

Abstract The first offshore drilling for oil in Texas occurred along Goose Creek, 21 miles southeast of Houston on Galveston Bay. In 1903, John I. Gaillard noticed bubbles coming to the surface of the water. With a match, he confirmed that the bubbles were natural gas, a strong indication of oil deposits. The discovery well was drilled and hit oil on 2 June 1908, at 1600 ft. In 1916, a well at Goose Creek hit a 10,000-barrels-per-day (bbl/day) gusher at a depth of 2017 ft ( Figure 1 ). Initially, that well produced 8000 bbl/day. The community changed overnight as men rushed to obtain leases, to build derricks, and to drill wells. Within two months, the well leveled off to 300 bbl/day. The largest well of the field was Sweet 16, which came in on 4 August 1917, gushing 35,000 bbl/day from a depth of 3050 ft. This well stayed out of control for three days before the crew could close it. The Goose Creek field is on a deep-seated salt dome with slightly arched overlying beds. When a hurricane hit in 1919, the Goose Creek oil field suffered tremendous property damage. The hurricane's relatively mild 39-mph winds destroyed more than 1450 oil derricks. At the time of the Goose Creek discoveries, the proper equipment for finding new oil fields included a Brunton compass, a K&E stadia handbook with Jacob's staff, a 7-ft stadia rod, a small bricklayer's hammer, and of course a couple of matches. In contrast, this book gives

Abstract Reflection seismology is the science of examining the earth’s interior through the analysis of mechanical waves. Seismic waves are bent, reflected, refracted, diffracted, and scattered. The emitted signal is weakened by these effects as well as geometric spreading and attenuation. Seismic waves are generated by controlled sources and travel through fluids, solids, and porous solids. In this chapter, we consider those properties of waves that do not depend on the kind of material supporting the wave propagation. For example, Snell’s law is a general property of wave motion but differs in detail between reflection of acoustic and elastic waves. In this chapter, when considering a general property such as Snell’s law, we will discuss the scalar (acoustic) wave case.