Dean Clark

The 1980s—boom and bust

In his 1981 Presidential Address, Kevin Barry cited figures that remain, a quarter century later, stunning: 744 seismic crews were active in the United States alone, estimated worldwide spending on geophysical surveys increased by 46% between 1979 and 1980, and was expected to grow by another 25% (to US

Sampling and the Nyquist frequency

4 billion) in 1981, and SEGs revenues for 1981 were US

Basic Seismology 14—Michael Faraday and the eikonal equation

3.5 million (eight times more than a decade earlier).

Kenneth E. Burg

Swiss‐born Leonhard Euler (1707–83), who lived primarily in Germany and Russia, was the most prolific mathematician of all time. Few people, in any branch of science, have even approached his astonishing publication record—a large percentage of which is of the first importance.

Introduction to this special section: Attenuation and spectral decomposition

It will probably surprise some to see the name of Michael Faraday (1791–1867) in this series because he is rarely, if ever, associated with seismology or mathematics. However, some of Faradays concepts provide an effective analog for some fundamentals of exploration seismology. It is also pleasant to revisit Faradays life which is one of the most inspiring stories in the history of science and which itself has some lessons that bear re-examination.

Whither geophysical technology? The views of the vendors

It is ironic that geophysics benefited from the insight of Kenneth Burg, among the first and most on‐target in predicting at least two industry‐wide technological revolutions, because his presence in the profession was due to an astonishingly inaccurate technological assessment by his grandfather.

A wave at a boundary: Reflection, transmission/refraction, and diffraction

Attenuation of seismic waves is one of the oldest areas of concern for exploration geophysicists and spectral decomposition is one of their newest tools but, despite their very different vintages, both are breaking new ground as shown by the four articles in this section.

The oldest continuously operating reflection seismic crew in the world

The first SEG Annual Meeting covered by TLE was in 1982. The biggest computer advertisers (each with a two-page spread in TLEs convention preview issue) were Control Data Corporation, ELXSI, and Sperry Univac. They were gone within a few years, as were some (if not most) of their successors. Cray, the dominating supercomputer presence at conventions in the late 1980s, was mergered into convention semiobscurity in the 1990s. However, in a recent transaction that went virtually unnoticed by the major news media, Cray was resold and might be primed (unlike Prime computers, which failed to make it out of the 1980s) for a convention comeback.

Basic Seismology 13—Huygens' principle

“Give me a place to stand,” Archimedes said, “a lever and a rock, and I will move the Earth.” He very likely was the first scientist to speculate about moving the Earth, but modern exploration geophysicists were probably the first to make such a daring idea the very underpinning of their systematic investigations. For, indeed, moving the Earth — admittedly on a very small scale, nothing like what Archimedes had in mind — is precisely what we must do to generate the seismic waves we need to bring us information about the subsurface.

The 1940s—a decade of consolidation

Exxon Company, USA, then Humble Oil and Refining Company, put its first seismic reflection crew in the field in 1930. Party One, renamed Party Six a few years later, never left, setting a continuous performance record for reflection crews that is believed unequalled. The history of this single party offers, in one compact package, virtually the entire story of the evolution of the reflection method’s field operations.