Seismic Data

Seismic data is displayed as lines (traces) which are georeferenced by the receiver point and adjusted based on the sample strength. For analysis, an option to fill in the wiggles is provided.

Seismic data is acquired by generating a loud sound at one location and recording the resulting rumblings at another location. The source or shot which generates the sound is typically an explosion or vibration on land or at sea. Typically, a line of shots is fired. If one line is recorded, the data is a 2D survey. If more than one line is recorded, the data is a 3D survey. Each shot is recorded by many receivers. The object of recording is to infer geological subsurface structure from the strength (amplitude) of the recorded signal at different times in the recording.

Seismic data is almost always stored as a sequence of traces, each trace consisting of amplitude samples for one location (physical or logical).

A trace begins life as the recording from one receiver. The recording is sampled at some discrete interval, typically around 4 milliseconds, and lasts for some duration, typically 5 or more seconds. After the initial recording, the traces can be processed in a number of ways. This processing usually changes the absolute amplitudes such that amplitude units are irrelevant, and only relative amplitudes are significant. Also the trace may reflect a logical ordering different from the original (shot,receiver) pair.