EARTHQUAKE TIME HISTORY FILES (otherwise known as seismograms!)

The files in this directory contain 3 minutes of data from the 
Berkeley Digital Seismic Network station SAO for the moment magnitude 
(Mw) 5.2 earthquake which occurred near San Juan Bautista, CA, on 
August 12, 1998. 

Location from the Berkeley Seismological Laboratory
(courtesy of Bob Uhrhammer)

Date        ->    08/12/1998
Origin Time -> 14:10:25.4054   ( 0.0382)
Latitude    ->      36.76570   (  0.110)
Longitude   ->    -121.43290   (  0.337)
Depth       ->         9.538   (  0.151)
Std Error   ->         0.148

The numbers in paranethesis are the "nominal" uncertainties
in the earthquake location.  SAO is approximately 1 km W 
of the epicenter of the event.   For additional information
on this earthquake, visit the Web page:

http://www.seismo.berkeley.edu/seismo/eqw/eqw_98.08.12.html

The data streams are for the Vertical (Z), North (N) and 
East (E) components of a forced balance accelerometer 
(Kinemeterics FBA-23). The data is in digital counts 
and is proportional to ground acceleration. The sample rate is 80
samples-per-second. The data has been converted from mini-SEED into ASCII 
format. The sensitivty is 54,840 counts/(m/s**2) on the Z-component,
54,307 counts/(m/s**2) on the N-component, 
and 54,914 counts/(m/s**2) on the E-component.

The three files:

SAO.BK.HLZ.98224141000
SAO.BK.HLN.98224141000
SAO.BK.HLE.98224141000

contain the data:

SAO HLZ: rate=80 (1998.224 14:10:00.0121 to 1998.224 14:13:00.0123) : 
14400 points, 0.3 msec correction, (min,max,max_step = 0.0,0.3,0.1 msec)

SAO HLN: rate=80 (1998.224 14:10:00.0121 to 1998.224 14:13:00.0123) : 
14400 points, 0.3 msec correction, (min,max,max_step = 0.0,0.3,0.1 msec)

SAO HLE: rate=80 (1998.224 14:10:00.0121 to 1998.224 14:13:00.0123) : 
14400 points, 0.2 msec correction, (min,max,max_step = 0.0,0.2,0.1 msec)

where HLZ is the vertical component, HLN is the
north component, and HLE is the east component.


There are two images in this directory made with "snapshot". The
first (SAO.3min) shows the whole 3-minute record. The second (SAO.4.5.sec)
shows the largest amplitude 4.5 seconds of the revent. Close examination
of the data following the main shock shows about 1/2 dozen small aftershocks
that occurred in the 2+ minutes after the event.  The images are
in Sun raster files.

Rick McKenzie
Staff Research Associate
Berkeley Seismological Laboratory