Background
The Standard for the Exchange of Earthquake Data (SEED) was adopted by the FDSN in the 1987 and served as the dominant standard for seismological research data archiving and exchange for many decades.
The previous specification of miniSEED, latest 2.4, is defined as a subset of SEED that contains only data records.
Changes relative to 2.4
An overview of significant changes between miniSEED 2.4 and this specification:
Adoption of FDSN Source Identifiers, replacing independent SEED codes (network, station, location, channel).
Incorporate critical details previously in blockettes (actual sample rate, encoding, microseconds) into the fixed section of the data header
Increase sample rate/period representation to a 64-bit floating point value
Increase start time resolution to nanoseconds
Specify fixed byte order (little endian) for the binary portions of the headers and define a byte order for each data encoding
Drop legacy data encodings and reserve their values so they are not used again in the future
Add a format version
Add a data publication version
Add CRC field for validating integrity of record
Add a “mass position off scale” flag
Add “Recenter” (mass, gimbal, etc.) headers
Add “ProvenanceURI” header to identify provenance documentation
Replace the blockette structure with flexible extra header construct:
Specify a reserved set of extra headers defined by the FDSN, provide schema for validation
Previous flags and blockette contents defined in reserved extra headers
Allow arbitrary headers to be included in a record
Remove the restriction on record length to be powers of 2, allow variable length
Near complete preservation of miniSEED 2.4 data. Information that is not retained is limited to: clock model specification per timing exception (current specification only allows a single clock model specification per record), Blockettes 400 (Beam) & 405 (Beam Delay) and Blockette 2000 (Opaque Data).