UCB.CATALOG(5) Headers, Tables, and Macros UCB.CATALOG(5) NAME UCB.CATALOG, ucb.catalog, UCB.PHASE, ucb.phase - description of UC Berkeley phase and catalog file format DESCRIPTION The UCB phase and catalog format is an ASCII format used to store information about events that were located and cataloged by the Seismological Laboratory at UC Berkeley. The catalog file contains a single summary line per event, while the phase file contains the event summary line as well as optional phase, scalar moment, and comment lines for each event. UCB CATALOG SUMMARY LINE FORMAT (catalog and phase files) Column Format Contents _________________________________________________________________________ 1-4 4d Year of event 5-6 2d Month of event 7-8 2d Day of event 10-11 2d Hour of event 12-13 2d Minute of event 14-20 7.4lf Second of event 22-29 8.4lf Latitude of event (decimal degrees, N is positive) 31-39 8.4lf Longitude of event (decimal degrees, E is positive) 41-48 8.4lf Depth of event (kilometers) 50-53 4.2lf BMAG - Magnitude calculated from 14-kg Benioff records 55-57 3d Number of observations used to calculate the BMAG 59-62 4.2lf MLT - Traditional ML magnitude calculated from photographic or synthetic Wood-Anderson records, mostly at ARC, BKS, MHC, or MIN 64-66 3d Number of observations used to calculate the MLT 68-71 4.2lf MLN - Network ML magnitude calculated from synthetics from any BDSN station 73-75 3d Number of observations used to calculate the MLN 77-80 4.2lf Mw - Moment magnitude calculated from BDSN broadband records 82-84 3d Number of observations used to calculate the Mw 86-94 5.3le Scalar moment of event (dyne-cm) 96-98 3d Number of observations used to calculate scalar moment 100-102 3d Number of observations used to calculate hypocenter 104-106 3d Maximum azimuthal gap (degrees) 108-113 6.2lf Distance to nearest station (kilometers) 115-121 7.4lf Error in origin time (seconds) 123-129 7.4lf Error in latitude (kilometers) 131-137 7.4lf Error in longitude (kilometers) 139-145 7.4lf Error in depth (kilometers) 147-153 7.4lf RMS residual of phases used in location 155 c Quality of event hypocenter (A-D, _ if no quality) 157 c Event felt flag (F = felt, _ not reported felt) SunOS 5.5.1 Last change: 09 February 1995 1 UCB.CATALOG(5) Headers, Tables, and Macros UCB.CATALOG(5) UCB PHASE LINE FORMAT (phase file only) Column Format Contents _________________________________________________________________________ 1-4 s Phase card identifier ($PHS) 6-9 s Station name 11-14 s Instrument type ('x' if unknown) 16 c Component ('x' if unknown) 18 c Phase onset (0-4 for GS phases, e or i for UCB phases) 20-27 s Phase name ('x' if unknown or no phase) 29 c Ground motion (c/d, +/-, 'x' if unknown or no information) 31-34 4d Four-digit year of phase pick 35-36 2d Two-digit month of phase pick 37-38 2d Two-digit day of phase pick 40-41 2d Two-digit hour of phase pick 42-43 2d Two-digit minute of phase pick 44-50 7.4lf Seconds of phase pick 52-59 8.4lf Distance from station to epicenter (km) 61-66 6.2lf Azimuth from epicenter to station (degrees) 68-73 6.2lf Amplitude associated with phase pick (in mm, if any) 75-78 6.2lf Associated coda duration (seconds if any, zero if none) 82-89 4.2le Magnitude associated with phase pick (if any) 91 c Flag for phase used in location (if used = 'Y', else = 'N') UCB AMPLITUDE LINE FORMAT (phase file only) Column Format Contents _________________________________________________________________________ 1-4 s Amplitude card identifier ($AMP) 6-9 s Station name 11-14 s Instrument on which amplitude pick was made ('x' if unknown) 16 c Component ('x' if unknown) 18-21 s Amplitude type (see below for explanation) 23-28 6.2lf Amplitude (mm) 30-35 6.2lf Associated coda duration (seconds if any, zero if none) 37-44 4.2le Magnitude calculated from amplitude UCB SCALAR MOMENT LINE FORMAT (phase file only) Column Format Contents _______________________________________________________________ 1-4 s Scalar moment card identifier ($SMO) 6-9 s Station name 11-14 s Instrument ('x' if unknown) 16 c Component ('x' if unknown) 18-21 s Moment identifier (always 'MO') 23-28 6.2lf Amplitude (mm) 30-35 6.2lf Associated coda duration (seconds) 37-44 4.2le Scalar moment calculated using Bolt-Herraiz method (dyne-cm) SunOS 5.5.1 Last change: 09 February 1995 2 UCB.CATALOG(5) Headers, Tables, and Macros UCB.CATALOG(5) UCB COMMENT LINE FORMAT (phase file only) Column Format Contents _________________________________________________ 1-4 s Comment card identifier ($COM) 6-157 s Comment SUMMARY END OF EVNET LINE FORMAT (phase file only) Column Format Contents _________________________________________________ 1-4 s Comment card identifier ($END) DETAILS LOCATIONS The procedure used to compute locations has evolved through time. For events before 1960, locations were computed by drawing arcs on a map. Beginning in the early 1960s, computer procedures were implemented. These have been updated through time. Currently, the location procedure used is called RELP (Regional Earth- quake Location Program), written by Robert Uhrhammer. This code uses P and S readings hand-timed from BDSN broadband instruments and Calnet P readings. For further details, contact Dr. Robert Uhrhammer. E- mail addresses are given at the end of these manual pages. MAGNITUDES The catalog contains four different magnitude types, BMAG, MLT, MLN, and Mw. The first three magnitudes are all 'local magnitudes', based on the magnitude scale defined by Richter in 1935 (Richter (1935), Gutenberg & Richter (1942)) and updated in 1942. This scale is based on the maximum trace amplitude of the event on a standard Wood- Anderson torsion seismograph. The differences between the three 'local magnitude' measures are as follows: BMAG is calculated from 14-kg Benioff records at several UCB short-period stations, and has been calibrated against the Richter magnitude (ML) from the Berkeley catalog. MLT is the Richter magnitude calculated from Wood- Anderson records primarily at Arcata (ARC), Berke- ley (BKS), Mount Hamilton (MHC), and Mineral (MIN). Prior to January 16, 1993, these magni- tudes are calculated from readings obtained from photographic records. After January 16 1993, these SunOS 5.5.1 Last change: 09 February 1995 3 UCB.CATALOG(5) Headers, Tables, and Macros UCB.CATALOG(5) magnitudes are calculated only from Wood-Anderson records synthesized from broadband recordings made at these sites. Some early MLT magnitudes may have used readings from other Berkeley Wood- Anderson stations, such as Berkeley (BRK), San Francisco (SFB), Palo Alto (PAC), and Vineyard (VIN). MLN is the Richter magnitude calculated from synthetic Wood-Anderson recordings generated from records made by BDSN broadband instruments. Thus, these magnitudes are determined from stations in addi- tion to ARC, BKS, MHC, and MIN. These magnitudes start on January 1, 1993, with scattered earlier events having MLN as well. Mw is the moment magnitude determined using broadband records acquired from the BDSN (Berkeley Digital Seismic Network), TERRAscope, and IRIS. There are three methods used at UC Berkeley for calculating regional Mw: a full waveform inversion procedure developed by Dr. Douglas Dreger, a near-field body-wave inversion procedure developed by Dr. Robert Uhrhammer, and a surface wave inversion code developed by Michael Pasyanos and Dr. Barbara Romanowicz. For any event for which any one or all three of these methods can be applied, a 'best' moment tensor is calculated. This is the solution from which moment magnitude (Mw) and scalar moment are calculated. There are very few magnitudes listed for events prior to 1931, and magnitude listings are spuratic until 1948. Prior to 1984, only one magnitude value was cal- culated for any event. All magnitudes in the catalog before 1984 are located in the MLT field, although a small number of these magnitudes may actually be BMAG magnitudes. For further information regarding moment magnitudes, please contact the author of the code in which you are interested. E-mail addresses are given at the end of this document. MOMENT The catalog contains a field for scalar moment. His- torically, there have been two methods used to calcu- late scalar moment. Starting in 1984, scalar moment was calculated based on a duration- amplitude-distance method derived by Bolt & Herraiz (1983). In 1992, moments were determined for some scattered events based on the moment tensor inversion techniques listed above, SunOS 5.5.1 Last change: 09 February 1995 4 UCB.CATALOG(5) Headers, Tables, and Macros UCB.CATALOG(5) and starting in 1993, these moments became much more regular. For further information, see the list of references at the end of these manual pages. QUALITY and FELT The catalog contains columns for felt information and a quality descriptor. If the felt flag is given as 'F', the event was reported felt by at least one person. If the felt flag is given as '_', no information that this event was felt was received by the UC Berkeley Seismo- logical Laboratory. The quality descriptor is mainly used in events prior to the early 1960s, when the UCB short-period network was installed. The descriptor was intended as a meas- ure of the accuracy of the location, but it was only a subjective measure based on the intuition of the person locating the event. The scale runs from A-D, with A being highest quality and D being lowest quality. AMPLITUDE TYPES The UCB catalog contains amplitudes measured on a number of different instruments. The codes to identify the various amplitudes are outline below: WA traditional photographic Wood-Anderson torsion seismograph. (Gain: nominally 2080X) WAS synthetic Wood-Anderson HGWA High Gain W-A, a traditional W-A sent through a phototube amplifier and recorded on a helicorder. (Gain: nominally 14000X) LGWA Low Gain W-A, a traditional W-A sent through a phototube amplifier and recorded on a helicorder. (Gain: nominally 700X) 100X photographic W-A run with a gain of 100X. All these amplitudes are used to determine magni- tudes. The HGWA and LGWA are used only to calcu- late the BM magnitude. The WA, WAS, and 100X amplitudes are used to calculate ML, and the WAS amplitudes are also used to calculate MLN, the synthetic ML from the entire network. SEE ALSO CATALOG(5), eqselect(1). SunOS 5.5.1 Last change: 09 February 1995 5 UCB.CATALOG(5) Headers, Tables, and Macros UCB.CATALOG(5) Bolt, B.A., and Miguel Herraiz (1983). Simplified estima- tion of seismic moment from seismograms, _B_u_l_l. _S_e_i_s_m. _S_o_c. _A_m., 73, pp.735-748. Gutenberg, B., and C.F. Richter (1942). Earthquake magni- tude, intensity, energy, and acceleration, _B_u_l_l. _S_e_i_s_m. _S_o_c. _A_m., 32, pp.163-191. Richter, C.F. (1935). An instrumental earthquake magnitude scale, _B_u_l_l. _S_e_i_s_m. _S_o_c. _A_m., 25, pp. 1-32. CONTACTS For further information regarding any of the following sub- jects, please contact the corresponding people as listed below: SUBJECT CONTACT _______________________________________________________________________ Locations Dr. Robert Uhrhammer bob@perry.berkeley.edu Magnitudes Rick McKenzie rick@perry.berkeley.edu Dr. Robert Uhrhammer bob@perry.berkeley.edu Moment Tensors: Body Wave Dr. Douglas Dreger dreger@perry.berkeley.edu Near-Field Dr. Robert Uhrhammer bob@perry.berkeley.edu Surface Wave Michael Pasyanos mike@perry.berkeley.edu Dr. Barbara Romanowicz barbara@perry.berkeley.edu General Questions Rick McKenzie rick@perry.berkeley.edu Analyst bdsn@perry.berkeley.edu BUGS Every effort has been made to avoid introducing error to the catalog entries. However, no method is 100% foolproof. If you find what you feel may be an error, please document it (i.e. what entry is in error, etc.) and send electronic mail to bdsn@perry.berkeley.edu. AUTHOR Greg Anderson, UC Berkeley Seismological Laboratory SunOS 5.5.1 Last change: 09 February 1995 6