PICKFILE(UW) PICKFILE(UW)



NAME
Pickfile - Format of Earthquake Pickfiles at UW

SYNOPSIS
For each earthquake processed by the UW seismic network,
there is a file, called a pickfile, that contains informa-
tion about the earthquake, including P and S arrival
times, amplitudes, hypocenter parameters, and magnitude.
They are located (and usually ``archived'') in subdirecto-
ries named after the year and month in which the earth-
quake occurred. For example, all pickfiles for the events
in February, 1988 are in the directory ~seis/P/8802. Each
pickfile has a twelve-character name that begins with 11
digits giving, to a precision of 10 seconds, the date and
time at which recording of seismic signals from an event
began. A suffix specifying the region in which the event
occurred is appended to the date-time to create the pick-
file name. The pickfile printed at the end of this docu-
ment is named 89011713551p, indicating that recording
began in 1989, on Jan 17, within ten seconds after
13:55:10 UT, and it was located in the Puget Sound region.
The pickfile contains information in several formats,
keyed by the symbol in column 1 of the line. The first
line of a pickfile is called the header, and it starts
with the letter 'A' in column 1. Each subsequent line in
the file begins with a different upper case letter or
blank in column 1. The information in these lines and the
formats of the lines are described below, arranged by the
character that appears in column 1:

--------------------------------------------------
A in column 1 -
A header line begins with an 'A' in the first column and con-
tains the date and time of occurrence of the event as well as
a location, magnitude and some quantities indicating the qual-
ity of the hypocenter determined.

A code for event type appears in column 2. The approved types
are: X- Known explosion, P- Probable explosion, F- Felt event,
T- Teleseism, H- Hand picked (other `types' take precedence),
L- Low frequency volcanic, R- Regional earthquake (outside net-
work), 8- Earthquake information from another source and event
occurred between 1800 and 1899, 9- Earthquake information from
another source and event occurred between 1900 and 1999.

Because the origin time of an event is always given by tabulat-
ing the number of seconds the event occurred after the date
given by the first ten digits of the pickfile name (described
above), it is possible, in some cases, for the seconds to be
given as a negative quantity or a positive quantity greater
than 60. A sample header for the pickfile named 89011713551p
is shown below. It indicates that the origin time was 28.82
seconds after 13:55 UT. However, if the earthquake had
occurred at 13:54:50.18, ie 9.82 seconds before 13:55 UT the
first few columns of the header card would have been
AF8901171355 -9.82...... In both cases, the digits 1355 would
be used in the header line and the pickfile name because the
recording of the data began in the minute following 13:55 UT.

An explanation of the other quantities in the header line is
given in any of the Quarterly Network Reports.

Events with locations have header lines with 75 characters.
Unlocated events have header cards with only 14 characters.
Header format for located events-
Type,Year,Month,Day,Hour,Min,Sec,LatDeg,NS,Latmin*100,LongDeg,EW,Lonmin*100
Depth,Fix,Magnitude,Numsta,numphase,Gap,Mindelta,RMS,ERR,Q1,Q2,Velmodel
FORMAT('A',A1,5I2,F6.2,I3,A1,I4,I4,A1,I4,F6.2,A1,F4.1,I3,'/',I3,I4,I3,F5.2,f5.1,2A1,1x,A2)
ATYYMMDDHHMM SS.SS LLNMMMM LLLWMMMM DD.DD* M.M NN/0NN GGG DD R.RR EE.EQQ VV
Example:
AF8901171355 28.82 47N3919 122W1143 1.53 3.3 38/042 51 8 0.24 0.9BB P3

Header format for unlocated events-
Type,Year,Month,Day,Hour,Min,Region_code
FORMAT('A',A1,5I2,1x,A1)
ATYYMMDDHHMM C
Example:
A 8901171355 p

--------------------------------------------------
blank in column 1 -
A phase line has a blank in column 1 and can include arrival
time and amplitude data from any number of phases. For each
phase, the following are specified: phase type (P or S), first-
motion polarity (example - C, D, +, -, Ce, +n, -?), arrival
time (sec), use_code (see below), weight (0 to 4, with 0 being
full weight. A phase with a weight of 4 is not used in the
location), reading uncertainty for phase in seconds, and
arrival time residual (sec). A phase line may end with peak-
to-peak amplitude in digitized counts read from the station.
Station names usually have only 3 upper case characters
although some may have 4. Presently, the fourth character is
either Z, N, or E for stations having more than one seismome-
ter, each of which is sensitive to a different component of
ground motion (Z=vertical, N=north-south, E=east-west). The
station name is followed by the coda duration in seconds and
may be zero if no duration is read. The first phase is usually
a P phase but it need not be. An S-phase, if included, will
always follow a P-phase, if it is present. An amplitude field
will follow any phase fields, but may be entirely missing if
there are no amplitude data. A line containing a station name
only indicates that the trace-data for the station were saved
on magnetic tape but no phases were picked, usually because of
low signal-to-noise ratio.

Phase card Format-
Staname,Duration,type,Pol,Sec,Use_code,Weight,Reading Uncertainty,Residual,(amplitude-field)
Format(' ',A4,I4, (P info field),(S info field),(Amp. Info field) )
Specifically,
Format(' ',A4,I4, (1x,A1,A2,F6.2,A1,I1,F5.2,F5.2), ..., (1x,A1,1x,I4,1x,A1,1x,I4,1x,A1) )
NNNN DDD PCe SS.SSUW E.EE R.RR S SS.SSUW E.EE R.RR A PPPP W SSSS W
Example:
BHW 97 PD 33.23 0 0.01-0.15 S 37.26 2 0.07 0.33 A 23 1 120 1















Information for each phase is listed in a phase field of 22
characters. The phase field lists type of phase, polarity,
time, use_code, weight, reading uncertainty, and time residual
associated with the phase. The 'use_code' character is a blank
if the phase was used in the location specified on the header
card. Any other character means this phase was NOT used in the
current location, and the character indicates why the phase was
not used: X - pick weight too low , D - distance to station too
great, R - residual too large, N - S-waves are not used in this
location, S - pick was weighted out in the velocity model
(assigned a 4 weight). The pick weight is usually determined
by the uncertainty in the arrival time of a phase by program
ping. Weights 0, 1, 2, 3, and 4 correspond to uncertainties
<0.03, <0.06, <0.15, <0.30, and >0.30 seconds respectively.
However, the weight may be changed independently by the ana-
lyst.

The amplitude field has 16 characters and is made up of five
parts:
A PPPP W SSSS W
The `A' is the amplitude field code, PPPP is the Peak-Peak
amplitude in digital counts of the P-wave, SSSS is the same for
the S-wave, and W is a one letter quality code for each of the
amplitudes preceding it. It may be an underscore character `-'
if the amplitude was not read. For stations SEE and SEN, the
maximum peak-to-peak amplitudes of P and S are recorded,
regardless of when the maxima occurred. Amplitudes at these
stations are used to determine Wood-Anderson magnitude.

--------------------------------------------------
E in column 1 -
Indicates error line for summary of statistics of location.
See the detailed manual for the location routine spong for the
meanings of these fields.

Error line format-
Vel,RMS,MeanRMS,SDabout0,SDaboutMean,SSWRES,NDFR,FIXXYZT,SDx,SDy,
SDz,SDt,Mag,MeanUncert
FORMAT('E',1x,A2,f6.2,3f6.3,f8.2,i4,a4,5f5.2,5x,f4.2)
E VV RR.RR M.MMM S.SSS S.SSS WWWW.WW NNN XYZT D.DD D.DD D.DD D.DD M.MM U.UU
Example:
E P3 0.24 0.173 0.251 0.298 153.88 38 0.31 0.35 0.87 0.09 3.27 0.06


--------------------------------------------------
S in column 1 -
Indicates a magnitude line summarizing magnitudes other than
the coda magnitude (which appears in header-line). One or more
magnitudes may appear. Each occupies a field of 8 spaces. Mag-
type is a two letter code like ML, MB, MS, MO, MW, MD indicat-
ing that the preceding number is a local-, body-, surface-,
moment-, or duration-magnitude. Source is a source-code. a=
UW (used only for SEE/SEN synthetic Wood-Anderson - do man
magit for more info); b= UW (used only for standard Wood-Ander-
son at UW (presently recorded on Helicorder in Johnson Hall at
half standard gain, ie 1400 rather than 2800); c= UW (general
use); u= USGS - National Earthquake Information Service; n=
Newport; p= Pacific Science Geocenter, Victoria

Format for extra magnitudes line-
mag1,magtype1,source1, mag2,magtype2,source2, etc.
FORMAT('S', (f5.2,A2,A1), (f5.2,A2,A1), .....)
Sxx.xxCCSxx.xxCCSxx.xxCCSxx.xxCCS .......
Example:
S 3.27MLa 3.32MLb 3.40MBu

--------------------------------------------------
I in column 1 -
Indicates an intensity line summarzing felt information.

Intensity line format-
MaxI,Area,L-source,Hyp-source,Mag-source,Scale,DupFlag,Comments
FORMAT('I',1x,A4,1x,I6,1x,A2,1x,A2,1x,A2,1x,A2,1xA1,2x,A)
I IIII AAAAAA LL HH MM SS D Comments...

--------------------------------------------------
C in column 1 -
Indicates a comment card having any ASCII characters and any number of comments following the letter C.

--------------------------------------------------
D in column 1 -
Used to list dead stations for this event on the data acquisition
computer in fields of four characters.

--------------------------------------------------
M in column 1 -
The character M is reserved for focal mechanism cards.
M-cards are created during routine seismic processing using program
focal which, in turn, uses program fpfit.
If several solutions are possible, several M-cards may be placed in the
pickfile.
The format for the M-card is as follows
(do man fpfit for more information):

Plane#1,Plane#2,Pole#1,Pole#2,P-axis,T-axis,Source,FIT,quality,
velmod,Fault_plane_indicator
Example:
M F 50 40 G 304 77 U 230 50 V 124 13 P 276 23 T 162 44 fp-fit 0.08 B|A E3 00
General Form:
M F AAA PP G AAA PP U AAA PP V AAA PP P AAA PP T AAA PP Source Fit Q|Q VV In

F and G are the two possible nodal planes. U is the pole to
plane F and V is the pole to plane G (U is also the slip vector
if G is the fault plane and V is the slip vector if F is the
fault plane). P and T are maximum and minimum stress axes. An
azimuth (AAA) and dip (PP) are given for each of these six
quantities. For example, following the letter F on the card
are its azimuth and dip; following the letter G are its azimuth
and dip, and so forth for U, V, P, and T. Note that for
the planes F and G the azimuth (AAA above) refers to the
AZIMUTH OF THE DIP VECTOR (degrees measured clockwise from
north) defining each plane, not its strike. PP is the dip
(degrees) of the plane measured downward from the horizontal.
For a plane with a strike of N55E and dip of 30 to the SSE,
AAA=145 and PP=30. A plane striking N55E but dipping 30
degrees to the NNW has AAA=325 PP=30.

Source is usually an indicator of the source of the focal mech-
anism solution. For production focal mechanisms the label "fp-
fit" will occur here. FIT takes on a value 0.0 (perfect fit) to
1.0 (worst possible fit). See man fpfit or USGS Open File
Report 85-739. quality gives two quality factors for the the
solution, for example A | B. Both factors range from A (best)
to C (worst). See man fpfit or USGS Open File Report 85-739.
velmod is the velocity model used. For example, L0 indicates
a linear increase with depth. P3 indicates that the layered P3
velocity model was used, etc. The layered model is used by
default. fault_plane_indicator identifies whether a particular
plane (F or G) is identified as the preferred fault plane, 1 if
F is the preferred fault plane or -1 if G is the preferred
fault plane. The default is 0, ie no preferred fault plane.


EXAMPLE
(note: To save space, many stations have been removed in this
example of pickfile 89011713551p)

AF8901171355 28.82 47N3919 122W1143 1.53 3.3 38/042 51 8 0.24 0.9BB P3
E P3 0.24 0.173 0.251 0.298 153.88 38 0.31 0.35 0.87 0.09 3.27 0.06
SEN 0 P 31.48X4 0.04 1.00 S 34.56R4 0.00 2.78 A 0 _ 4032 1
SEE 0 P 31.39X4 0.02 0.91 S 34.89R4 0.19 3.11 A 0 _ 6112 3
SEV 0 P+n 31.34 1 0.04 0.06
SPW 107 PD 31.77 0 0.03-0.08
BHW 97 PD 33.23 0 0.01-0.15 S 37.26 2 0.07 0.33
HTW 106 PC 35.09 1 0.05 0.03 S 39.46 2 0.10-0.47
PGW 107 PD 35.59 0 0.01 0.10
RMW 141 PD 35.39 1 0.03 0.01
GMW 129 PC 36.91 1 0.05 0.20
GSM 0 P 38.81 2 0.08 0.00
MEW 0 P 40.03 2 0.09 0.30
JCW 115 PD 39.52 0 0.03 0.18
HDW 121 P-? 39.39 0 0.01-0.13 S 46.04R4 0.05-1.82
GHW 0 P+e 40.43 1 0.04 0.26 S 50.32R4 0.09 1.29
SHW 0 P 54.54D1 0.06-0.12
OTR 0 P 58.24R2 0.06 2.84
RVW 0 P 55.69D1 0.04-0.25 S 77.58D4 0.07 0.49
OFK
YEL
D REM EDM HSR CDF JUN STD LVP MTM MOX
S 3.27MLa 3.32MLb 3.40MBu
C FELT
C felt in Kirkland
C 2 later, smaller events slashed out





SEE ALSO
files(uw), ping(uw), spong(uw), punt(uw), magit(uw),
mcard(uw) focal, focu, focm



March 19, 1992 PICKFILE(UW)