Help and Documentation
Click on each topic below to expand to more information.
The NCEDC provides online search capabilities for the northern California earthquake catalogs of the USGS and BSL,
for the worldwide earthquake catalog of the ANSS,
and for the Enhanced Geothermal Systems (EGS) catalog.
Through SeismiQuery, you may check the inventory of the NCEDC, seeing what stations or channels are available for different time periods.
SeismiQuery was developed by the IRIS Data Management Center to provide a simple interface for making information queries and reviewing data holdings. The NCEDC has implemented SeismiQuery as a tool for querying the waveform archives. However, this interface is NOT currently configured to retrieve waveform data.
Help using SeismiQuery is available here.
Retrieving waveform data
The NCEDC has created a new set of FDSN-compliant web services to access data at the NCEDC. Web services provide simple functions that can be used from a web browser, command-line programs such as curl and wget, dedicated clients, and through programming languages such as perl, python, shell scripts, or MATLAB.
The FDSN web services provide a common specificiation to access common FDSN data types such as event information, station and information, and waveform data. The FDSN web services specification serves as a baseline level of compatibility, allowing data request tools to work with any FDSN data center that implementing these services.
Why web services? Web services at the NCEDC use a RESTful (Representational State Transfer) design to provide a simple stateless query and data retrieval system. RESTful Web services use the HTTP protocol and normally communicate with clients using TCP port 80, which is the default port used by web servers. Using HTTP and standard web server ports minimizes interference from firewalls, and allows you to use web services anywhere you can use a web browser -- from behind most firewalls, and through web proxies.
The NCEDC FDSN web services are designed to be compatible with the FDSN web services implemented at other FDSN data centers such as the IRIS DMC Web Services. Please visit the NCEDC Web Services Web Page for a complete list of NCEDC Web services and descriptions.
Web Services retrieve data in miniSEED format (no instrument response metadata). Instrument response metadata can be retrieved through web services as dataless seed (readable with rdseed), resp file format, or station XML. Full network IR metadata is available in our network directories
SWC retrieves data in miniSEED format (no instrument response metadata). Instrument response metadata can be retrieved through web services as dataless seed (readable with rdseed), resp file format, or station XML. Full network IR metadata is available in our network directories
DART (Real-Time Data)
DART (Data Available in Real Time) is a buffer of real-time telemetry MiniSEED data that is accessible through SWC or Web Services, or through a filesystem accessible through the web. miniSEED format has no instrument response metadata. Instrument response metadata can be retrieved through web services as dataless seed (readable with rdseed), resp file format, or station XML. Full network IR metadata is available in our network directories
Catalog and phase files at NCEDC are stored and retrieved in different formats for each data set. Overviews are available for the following catalogs:
These are the current formats supported by the NCEDC:
There are two commonly used time series file formats used by the the seismological community: SEED/miniSEED and SAC.
SEED format and the rdseed program:
As much as possible, waveform data archived at the NCEDC are made available in SEED (Standard for the Exchange of Earthquake Data) format.
The Standard for the Exchange of Earthquake Data (SEED) is an international standard format for the exchange of digital seismological data. SEED was designed for use by the earthquake research community, primarily for the exchange between institutions of unprocessed Earth motion data.
SEED files normally contain the digital timeseries as well as station and channel information describing the complete instrument response for each time series.
SEED is defined and developed by the FDSN Working Group on data exchange.
IRIS has developed and freely distributes the program rdseed which will read SEED files, extract station/channel instrument responses, and convert the seismograms to other standard user format such as AH, SAC, CSS, and miniSEED formats. The rdseed program is available from the IRIS DMC
Our newer services retrieve data in miniSEED format. miniSEED does not include instrument response metadata. Instrument response information can be retrieved as dataless seed (readable with rdseed), resp file format, or station XML.
- Station XML format response metadata can be retrieved through web services' fdsnws-station via a targeted query.
- Dataless seed format response information (readable with rdseed) can be retrieved through web services' ws-dataless via a targeted query.
- Resp file format response information (rdseed not needed) is available in our network directories by network (larger file with response information for all stations, all channels, for all time). A targeted query through web services' ws-resp is also available.
When you use data from this data center, please acknowledge both the
Northern California Earthquake Data Center (NCEDC) and the organization(s)
that contributed the data to the NCEDC.
Table of contributing organizations
The NCEDC has a developed a schema for earthquake data in collaboration with partners in southern California.
Information about the operation of the NCEDC is available from the
of the Berkeley Seismological Lab.
|Agency/Network||Catalog File Formats|
|BSL Northern California and surrounding areas: hypocenters, magnitudes, phase and amplitude readings, 1910-present (hypo and mag), 1984-present (phase and amp)[Now merged with USGS catalog)|
|USGS Northern California hypocenters and magnitudes, phase and amplitude readings, first-motion mechanisms, 1967-present (now merged with BSL catalog)|