NCSN Data Y2K Compliant

October 21st, 1999

October 21, 1999

The traditional formats used for archiving and distributing the NCSN earthquake catalog, phase, and focal mechanism data at the NCEDC were not Y2K compliant, as they contained only a 2 digit years. On October 21, 1999 the NCEDC started distributing the data in an updated Y2K compliant format. You can find documentation on the new Y2K compliant format on our documentation page.

The CNSS and UCB formats for catalog and phase data have not been changed, as they are Y2K compliant.

NCSN Byteorder problem resolved

October 20th, 1999

October 20, 1999

We have corrected the byte order problem that was detected earlier this year in a number of NCSN grm (waveform) files at the NCEDC. See the announcement: Byteorder problem detected in some NCSN waveform files for details.

A few (~ 500) of these events were determined to have possible problems, and will be reloaded from tape in the near future.

BK Network data available in SEED format

October 4th, 1999

October 4, 1999

As of October 4, 1999, the NCEDC can distribute all data for the entire BK network in SEED format with complete multi-stage instrument responses. This includes all seismic channels (broadband and strong motion), electric and magnetic field channels, and other geophysical channels from temperature and microbarograph sensors. The BK network includes the sparse broadband array known as the Berkeley Digital Seismic Network (BDSN) and the borehole sites of the Northern Hayward Fault (and, as of 2002, the borehole sites of the Mini-Plate Boundary Observatory Project).

Prior to this date, only a subeset of the BK network was available in full SEED format, and the instrument responses for the BDSN stations were described by a single-stage response which were not compatible with evalresp.

Most of the BK data channels are acquired from broadband seismic instruments, strong motion seismic instruments, electric field, or magnetic field sensors, and are described using multi-stage responses that are compatible with IRIS's evalresp program. However, selected channels, such as the temperature channel LKS and microbarograph channel LDS do not have responses can be represented with standard poles and zeros used for seismic sensors. These channels are described with a new POLYNOMIAL blockette which is currently not evalresp compatible.

IRIS has released a new version of RDSEED which will properly generated the response files for these channels, which is available from the IRIS DMC.

You may request BK data in SEED format by any of several methods.

  • You may query the BK data inventory at the NCEDC or generate and submit a NETDC request using the SEED Request form
  • You may send a NETDC request to

Note: on November 15, 2001, a new tool was added for querying the inventory of SEED data at the NCEDC.

If you have any problems with the new SEED volumes or SEED instrument responses, please contact us at

New 2.5 TeraByte Mass Store

April 1st, 1999

February 1, 1999

The NCEDC has upgraded its mass storage system for seismic and geophysical data sets to a 2.5 TeraByte storage system.

With funding from the USGS and BSL, the NCEDC purchased in mid-1998 a DISC jukebox which with capacity for 500 magneto optical (MO) platters, a small AIT tape jukebox, and the SAM-FS Hierarchical Storage Management (HSM) filesytem software. The initial DISC configuration housed two 2.6 GByte MO disk drives, and was upgraded in spring 1999 to four 5.2 GByte MO drives and 5.2 GByte media. The DISC jukebox in its current configuration can store up to 2.5 TBytes of data.

Data stored at the NCEDC is automatically written to both the MO disk platters for near-online storage and to the 25 GByte AIT tape system. The AIT tapes are removed from the jukebox when full and stored at an offsite facility.

Byteorder problem detected in some NCSN waveform files

March 12th, 1999

We recently discovered that we loaded 33,933 grm files onto the NCEDC in the WRONG BYTE ORDER. These events were inadvertently stored in VAX byte order instead of Sun byte order. The list of eventids can be found in the file


The grm file have now been renamed with a ".unknown" suffix on the jukebox until we can correct this error. In the meantime, if you have downloaded any of these events, the data will be in the wrong byteorder. We apologize for this SNAFU.

Note: this problem was resolved on October 20, 1999.

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