============================================================================== Interim Access to HRSN triggered data Last updated: 2006/05/17 General Information: This directory ftp://www.ncedc.org/pub/parkfield contains the following data: 1. The original HRSN data in LBL/segy format from 1987 - 1998. The source for the program segy2ms, which can convert these files to MiniSEED, can be found in the directory ftp://www.ncedc.org/pub/quanterra/ucb You will need the qlib2 library tar file in addition to the seg2ms tar file. 2. Event triggers from the HRSN and temporary PASSCAL broadband network (PASO-I) in Parkfield. Because of limited bandwidth between Parkfield and UC Berkeley, continuous data from the HRSN are transmitted to a central site at Parkfield for event detection. These event triggers are relayed to the BSL over a dedicated communication link. At present, the HRSN triggering system also retrieves data from the temporary PASSCAL deployment, but these data are not used for determining trigger times. The central triggering system was originally deployed in late 2000. Triggers from this date and from the first few months of 2001 are dominated by false events, as the HRSN experienced numerous problems with high noise levels. By late June 2001, most of the noise sources had been identified and steps had been taken to reduce noise levels. We anticipate culling the earthquakes from this set of triggers and creating a true catalog. 2. Event triggers: Triggers are listed in the files "redi.event.log.????", corresponding to different time periods: redi.event.log.2000 redi.event.log.2001.1 redi.event.log.2001.2 redi.event.log.2002 redi.event.log.2003 redi.event.log.2004 redi.event.log.2005 The break in the 2001 corresponds (roughly) with improvements of centralized detector. The entries in the log file are of the form 2001.284,23:44:57.0000 35.9452 -120.5416 0.00 0.00 No 0 0 0.00 100 0 65005476 11 km WNW of Parkfield, CA Currently, the triggering system assigns the event location to the center of the HRSN and uses this fixed location to extract waveform data. In the log files, the first entry in each line (e.g., 2001.284,23:44:57.0000) is the time of the trigger. The 8-digit number (e.g., 65005476) located at the beginning of column 82 is the event identifier and is the key to finding the corresponding waveforms. 3. Interim event waveform data: The waveforms may be found in the directories prelim.2000/ prelim.2001/ prelim.2002/ prelim.2003/ prelim.2004/ prelim.2005/ depending on the year of interest. The waveforms are stored in gzipped tar files, named with the event id. As an example, to find the waveforms corresponding to the event above, look for the file EQ.0065005476.tar.gz The tar files are created with the GNU gzip comamnd, and may be unzipped using the GNU gunzip command (e.g., gunzip EQ.0065005476.tar.gz) and the tarfile may be unpacked with the tar command (e.g., tar xvf EQ.0065005476.tar). This will create an event directory (EQ.0065005476) with the waveform data in MiniSEED records, as well as a few additional ascii files related to the triggering and extraction of waveform data. PLEASE NOTE: The location identifed with the trigger is FIXED and is NOT related to the true location of an earthquake. Starting on day 2003.355 (2003/12/21), the NCEDC started to archive continuous 250 Hz data as well as continuous 20 Hz data from the HRSN. The event files after this time contain only trigger information but no waveforms. All waveforms after 2003.355,00:00:00 are available by normal data retrieval methods from the NCEDC. Please see: http://quake.geo.berkeley.edu/ncedc/seed-waveforms.html Waveform inventory info is available at: http://quake.geo.berkeley.edu/SeismiQuery 4. Interim event waveform file format: The waveform files are in MiniSEED format, and are named with the SEED code prefix station.network.channel.location The HRSN network code is BP. The PASSCAL broadband array deployment uses the IRIS-assigned temporary network code XN. The program ms2sac can be used to convert the MiniSEED data files into SAC format. The source to ms2sac is available in the directory: ftp://quake.geo.berkeley.edu/pub/quanterra/ucb You will need both the ms2sac and qlib2 tar files. 5. Processed event waveform data As of October 2002, we are beginning to review and process the events and their waveform data. The first change that you will notice is that event data is being moved from the prelim directories to the following: For triggers that appear to be seismic events: imported.2000/ imported.2001/ imported.2002/ For triggers that are clearly not seismic events: deleted.2000/ deleted.2001/ deleted.2002/ Eventually these false triggers will be deleted from the system. For the time being, the processed event data will be accessed in the same way as the preliminary data. 6. Continuous waveform data While the event triggering algorithm is being tuned, continuous HRSN waveform data are being archived at the NCEDC. These data may be queried and retrived through the SEED data request mechanism http://quake.geo.berkeley.edu/ncedc/seed-waveforms.html 7. Miscellaneous directories: Very recent files may be found in the directory get/ and are moved periodically into the prelim directory. The directories temp/ bin/ are only used for data transport and administrative programs. No files should be accessed from these directories. 8. More information For more information on the HRSN, see http://quake.geo.berkeley.edu/hrsn/ ==============================================================================