An image of seismic line which was originally encoded in the SEG Y format.

The SEG Y file format is one of several standards developed by the Society of Exploration Geophysicists for storing geophysical data. It is an open standard, and is controlled by the SEG Technical Standards Committee, a non-profit organization.

The format was originally developed in 1973 to store single-line seismic digital data on magnetic tapes. The specification was published in 1975,[1] and has since been named as the rev 0 specification. However, since its release, there have been significant advancements in geophysical data acquisition, such as 3-dimensional seismic techniques and high speed, high capacity recording.

The most recent revision of the SEG Y format was published in 2002, named the rev 1 specification.[2] It still features certain legacies of the original format, such as an optional SEG Y tape label, the main 3200 byte textual EBCDIC character encoded tape header and a 400 byte binary header.

SEGY file byte stream structure.svg

This image shows the byte stream structure of a SEG Y file, with the Revision 1. added Extended Textual File Header records.

Many SEG Y programs do not totally follow the specification. For example, ODEC uses the opposite byte order and adds 320 bytes to tail of each trace.[3]

See also


  1. Script error
  2. Script error
  3. "SIOSEIS DISKIN Documentation". Paul Henkart. Retrieved 2009-02-09.