SAFOD Pilot Hole data available at the NCEDC

January 15th, 2005

January 15th, 2005

The NCEDC is pleased to announce the availability of seismic waveform data from the San Andreas Fault Observatory at Depth (SAFOD) Pilot Hole in Parkfield. SAFOD is one component of the EarthScope Major Research Initiative funded by the National Science Foundations (NSF).

The SAFOD pilot hole is a separate, 2.2-km-deep scientific drilling experiment at the same surface location as SAFOD. This site is ~ 1.8 km SW of the San Andreas fault near Parkfield, CA, on a segment of the fault that moves through a combination of aseismic creep and repeating microearthquakes. It lies just north of the rupture zone of the 1966, magnitude 6 Parkfield earthquake, the most recent in a series of events that have ruptured the fault five times since 1857. The Parkfield region is the most comprehensively instrumented section of a fault anywhere in the world, and has been the focus of intensive study for the past two decades as part of the Parkfield Earthquake Experiment. The pilot hole is a collaborative effort between the International Continental Drilling Program (ICDP), NSF and the U.S. Geological Survey (USGS).

The first available SAFOD Pilot Hole data consists of ~ 5600 triggered events from 2002/09/13 through 2004/05/30. The data were recorded on 96 data channels (32 3-component sensors) at various depths at sample rates of either 250 Hz, 500 Hz, 1000 Hz, or 2000 Hz. Continuously recorded data surrounding the magnitude 6.0 Parkfield earthquake on 2004/09/28 will be available shortly.

For more information on SAFOD data available through the NCEDC, see the NCEDC SAFOD web page.

The NCEDC is a joint project of the University of California, Berkeley and the USGS. Please send us email at ncedcinfo@ncedc.org or fill out our comments form if you have questions or comments about these changes.

STP service available at the NCEDC

December 4th, 2004

December 4th, 2004

The NCEDC is pleased to announce the availability of STP (Seismic Transfer Program) service, originally developed by the Southern California Earthquake Data Center (SCEDC). STP is a client-server system that provides timeseries data in various data formats such as SAC, MiniSEED, and V0 (engineering) format. In the future, the NCEDC STP server will also provide earthquake catalog information and related phase data.

An STP client can request timeseries by either channel name(s) and time interval or by eventid. When timeseries are requested by eventid, only those waveforms directly associated with the eventid by the NCEDC will be provided.

A command-line STP client program, tested under Solaris (Unix) and Linux, can be downloaded from the directory

http://www.ncedc.org/ftp/pub/programs/stp/

Users should be be aware that the STP server performs some transformations on the raw timeseries. The STP server converts the raw timeseries into a uniformly sampled timeseries when delivering the timeseries to the STP client. If the STP server detects missing data or a time gap in the timeseries, it will supply a user-specified "missing value" to fill the gap in the timeseries. If the timeseries contains a negative timejump in the timeseries, the STP server may discard samples to create a uniformly sampled timeseries. STP may be best used to download event timeseries or relatively short segments from continuous timeseries.

A Web-based STP interface will be added in the future.

The NCEDC is a joint project of the University of California, Berkeley and the USGS. Please send us email at ncedcinfo@ncedc.org or fill out our comments form if you have questions or comments about these changes.

FISSURES framework implemented at the NCEDC

November 11th, 2004

November 11, 2004

We are pleased to announce that the BSL has implemented the FISSURES/DHI framework at the NCEDC. FISSURES is an IRIS project, led by the University of South Carolina.

Several FISSURES/DHI services have been implemented at the NCEDC and are available now:

Seismogram Service: (Waveform Information)

  • NCEDC_DataCenter
    • Continuous waveforms for BK,BP,CI,NC,NN,UL networks
    • Coming soon! Event waveforms for NCSN network (BK,CI,LA,NC,NN,NP,WR network codes)

Event Services: (Parametric Information)

  • BDSN_EventDC
    • BDSN catalogs from January 1984 to Present.
    • Coming soon! Historic BDSN catalogs from 1910 to 1984
  • NCSN_EventDC
    • NCSN catalogs from July 1966 to December 2002.
    • Coming soon! Current NCSN catalogs from 2003 to Present.

Network Service: (Instrument Responses)

  • NCEDC_NetworkDC
    • Instrument responses for networks AZ,BK,BP,CI,LB,NC,NN,NP,UL,US.
    • Coming soon! Instrument responses for WR network and completion of NN network

The NCEDC implementation supports the following FISSURES clients:

  • FISSURES

and in various IRIS newsletters:

  • Data Handling Infrastructure at the DMS
  • DMS Node Focus: University of South Carolina
  • Data Handling Interface for FISSURES
  • JEvalResp and JPlotResp versions 1.0 Released
  • FISSURES-Matlab interface

The NCEDC is a joint project of the University of California, Berkeley and the USGS. Please send us email at ncedcinfo@ncedc.org or fill out our comments form if you have questions or comments about these changes.

EVT_FAST now supports SEED format

November 11th, 2004

November 11, 2004

The NCEDC is very pleased to announce the availability of SEED and mini-SEED format output from the EVT_FAST data request tool. EVT_FAST is an email and Web-based tool for requesting event data recorded primarily by the Northern California Seismic Network.

The EVT_FAST email interface has been updated to support SEED and miniSEED output in addition to the original SAC binary, SAC ascii, and AH data formats. In addition, you may requests only selected data channels from these events on the basis of the SEED Station, Network, Channel, and Location codes. The EVT_FAST Web-based interface has also been updated to handle these enhancements.

The NCEDC is a joint project of the University of California, Berkeley and the USGS. Please send us email at ncedcinfo@ncedc.org or fill out our comments form if you have questions or comments about these changes.

NCSN data available in SEED format

November 11th, 2004

November 11, 2004

The NCEDC is very pleased to announce the availability of NCSN event waveform data in SEED format.

As a result, NCSN waveform data recorded since 3/1984* and associated metadata are now available through NCEDC tools such as:

In the near future, the NCSN event data will also be also be available with its SEED channel names through:

During 2003-2004, the NCEDC and NCSN finalized the CUSP-to-SEED channel mapping for the NCSN waveform. All of the hardware tracking and response information has been entered into the NCEDC database for the sites operated by the NCSN. Complete SEED responses for all of those data channels are now available from the NCEDC.

Additional work is required to collect, assemble, and verify the the instrument responses for data channels recorded by the NCSN at shared stations from contributing networks such as CA DWR, UNR, and SCSN. Until we have the correct instrument responses from the contributing networks, the NCEDC will provide a minimal SEED response that identifies these channels only as digital counts with unity gain so that timeseries data for these channels can be distributed in SEED format.

Completion of the NCSN SEED data coversion project has been a long, hard process. This project would not been completed without significant effort from USGS personnel Fred Klein, Gray Jenson, Bob Somera, Will Kohler, and David Oppenheimer and BSL/NCEDC personnel Doug Neuhauser and Stephane Zuzlewski. We are very grateful for their contributions to this project.

*Note:
The NCSN waveform archive consists primarily of earthquakes recorded and processed by the USGS CUSP system for the period 1984-2004. Earthquakes detected by systems other than the CUSP system result in phase and catalog entries at the NCEDC, but without waveforms. Waveforms should be available at the NCEDC for earthquakes with following range of NCSN event ID#'s:

         1  -30,999,999 
60,000,000 - 69,999,999

In addition to these event triggers, continuous data from the broadband stations operated by the NCSN are also available. The NCSN continues to perform Q/C on historic waveform data. If you find an event in the above range without waveforms, please send email at the address below.

The NCEDC is a joint project of the University of California, Berkeley and the USGS. Please send us email at ncedcinfo@ncedc.org or fill out our comments form if you have questions or comments about these changes.

Availability of Parkfield data

September 28th, 2004

September 28, 2004

The NCEDC is gathering data related to the 2004 Parkfield earthquake and making them available for researchers. Data are coming in now and will continue to be collected over the next few days and weeks.

Information about the available data is here:

2004 Parkfield earthquake data

The NCEDC is a joint project of the University of California, Berkeley and the USGS. Please send us email at ncedcinfo@ncedc.org or fill out our comments form if you have questions or comments about these changes.

BDSN HH & HL data now continuous

September 25th, 2004

September 25, 2004

As of September 25, the NCEDC is archiving continuous data from the BDSN HH and HL channels. In the past, we had archived waveform snippets or triggers for events for the HH and HL channels, while archiving BH and lower data rates continuously (with a few exceptions such as after large earthquakes such as the Denali and San Simeon events).

With this change in policy, the NCEDC will archive all data transmitted to the BSL. In general, we will not make efforts to fill in missing data from the HH and HL channels, unless the gaps occur in a record of interest. Our usual efforts to provide continuous data for the other channels will be the same.

The NCEDC is a joint project of the University of California, Berkeley and the USGS. Please send us email at ncedcinfo@ncedc.org or fill out our comments form if you have questions or comments about these changes.

BDSN BH channels changed to 40 Hz sampling

June 15th, 2004

June 15, 2004

The BSL converted most - but not quite all - of the BDSN BH data streams from 20 samples per second to 40 samples per second at the beginning of the GMT day on June 15th (day 167). This change affects: BDM, BKS, BRIB (broadband sensor only), CMB, CVS, FARB, HOPS, HUMO, JCC, JRSC, MHC, MNRC, MOD, ORV, PACP, PKD, POTR, RFSB (surface strong-motion only), SAO, SCCB, WDC, and YBH. Stations BRK, KCC, and WENL will be converted at the beginning of day 168.

As a result of this upgrade, stations CMB and SCCB are currently down, but we anticipate that they will be back up shortly.

This change in sampling rate was made in order to be consistent with the USArray specifications. USArray is part of the Earthscope project to study the structure and evolution of the North American continent.

At this time, we do no intend to change the sampling rate of the BP channels associated with the BSL borehole networks - the NHFN, MPBO, and HRSN.

June 16, 2004 - update

We completed the migration of the remaining BDSN stations today - BRK, KCC, and WENL. In addition, both CMB and SCCB have been brought back online.

The NCEDC is a joint project of the University of California, Berkeley and the USGS. Please send us email at ncedcinfo@ncedc.org or fill out our comments form if you have questions or comments about these changes.

Discrepancy in magnitude from database search

June 14th, 2004

June 14, 2004

We have discovered an inconsistency between the magnitudes reported in the new database search of the UC Berkeley earthquake catalogs (http://www.ncedc.org/db/Search/PI/dbselect.html) and the older, flat file search ( http://www.ncedc.org/ncedc/catalog-search.html). The inconsistency arose during the conversion of the catalog from an older PC-based database. The magnitudes currently reported in the database search were computed using a older set of station adjustments and thus differ from the magnitudes reported in the flat file search.

We are currently looking into the best way to resolve this inconsistency. For the present, we advise users for whom magnitude is a critical parameter to use the flat file search.

The NCEDC is a joint project of the University of California, Berkeley and the USGS. Please send us email at ncedcinfo@ncedc.org or fill out our comments form if you have questions or comments about these changes.

Calpine/LBL Geysers data added to the NCEDC

April 3rd, 2004

The NCEDC is pleased to announce the availability of seismic phase and waveform data from the Calpine/Lawrence Berkeley Labs seismic network that monitors seismicity in the vicinity of the Geysers geothermal field. The phase data begins 2003/04/04. Calpine/LBL stations can be recognized with their network code of "BG".

The BG data lowers the magnitude detection threshold for earthquakes at the Geysers and improves the location accuracy. For example, for the month of January, 2003 the NCSN located 248 earthquakes at the Geysers geothermal area. In that same period in 2008 we located 1,014 earthquakes, representing a four-fold increase. The large number of earthquakes that occur at the Geysers exceeds the reviewing capabilities of the NCSN staff. Consequently, only earthquakes above M1.0 at the Geysers are reviewed by analysts. Smaller magnitude events at the Geysers that are automatically detected by the CISN software are also in the catalog, but generally not reviewed.

The dense BG network allows detection of earthquakes at the Geysers with magnitudes lower than 1.0. The algorithm to compute coda durations was not designed for “short” codas (i.e., less than 7 sec). Therefore, earthquakes with magnitudes smaller than 1.0 typically have few, if any coda durations. Consequently, these small events have Md values of zero, which represents “no magnitude”. We anticipate developing a method to compute amplitude magnitudes for earthquakes below M3.0. We will then retroactively apply this method to all historic data. We have no estimated date for completion of this effort.

There is a temporary gap in BG phase data starting 2006/11/29 when the NCSN and UCB networks migrated to CISN processing software. On 2007/07/23 the NCSN established telemetry to the Calpine data acquisition system at the Geysers. This allowed the NCSN to integrate BG data into the CISN system in near real time. We have the BG phase and waveform data for this time gap, but we have no plans to integrate it into the catalog.

We expect event waveform data from the BG network for the period 2003/04/04 – 2006/11/29 to be online by the end of 2009. BG waveform data after 2007/07/23 is available, but as events only. The bandwidth of continuous waveform data recorded by the Calpine/LBL network exceeds the bandwidth of the communications link into the NCSN system. Therefore, continuous BG data is not available at the NCEDC.

The California Integrated Seismic Network greatly appreciates the cooperation of Calpine and Lawrence Berkeley Labs in monitoring earthquakes in California and their willingess to make this data set available to the public.


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