Southern California Seismographic Network#
The earliest seismographic stations in Southern California were installed by the Carnegie Institution of Washington. The seven-station network established in 1929 was transferred to the California Institute of Technology in 1937. The Caltech Seismological Laboratory operated the SCSN jointly with the US Geological Survey beginning in the early 1970s. The network grew during this time in response to the occurrence of large damaging regional earthquakes. Currently, the modern network operates 254 broadband seismographs with an average spacing of ~23 km.
The network has been well documented throughout its operational history.
Data is available through the Southern California Earthquake Center Data Center.
Stations#
From 1932-1992, the SCSN recorded close to 1000 channels of data from stations primarily in the southern California region in the United States with a few stations in Nevada.
See the SCECDC website for a complete list of analog stations available in their archive.
Instrumentation#
Wood-Anderson (WA)
Press-Ewing
Benioff
30-90
1-90
WWSSN SP & LP
Recording Medium#
Light sensitive paper (30x92cm)
ink on paper
Data Availability#
California Department of Water Resources
The original paper records, ~ 1 million, from 1928-1992 including special collections are currently maintained by the California Department of Water Resources in West Sacramento, California.
IRIS DMC
Select images (~70,000) from 1926, 1928-1932, 1937-1938 and special collections were scanned by Google in collaboration with UC Santa Cruz in 2009-2010 as part of the Google Books project.
As only a small part of the collection could be scanned, the images sent to Google were prioritized as follows (Brodsky & Kanamori, 2011):
- The Special Collection was scanned in its entirety. The Special Collection contains records collected by Caltech seismologists for their study on significant historical events. These records are predominantly from the Pasadena long‐period Press‐Ewing seismometers, but the collection is extremely heterogeneous and includes copies of records from a number of historical sites.
- The Southern California Seismic Network short‐period records were scanned with highest priority going to the earliest records. Records that were deemed too brittle to run through the scan apparatus were skipped.
More information can be found on the Seismo Archives website.
Special collections and records from 1926-1938 can be downloaded from the IRIS DMC spud database.
no. available |
format |
dpi |
color |
|---|---|---|---|
jpeg |
400 |
rgb |
Caltech Seismological Laboratory / SCECDC
Scanned images from pre-digital analog recordings of M>3.5 southern California earthquakes and several significant teleseisms recorded in Southern California between 1963 and 1992 are available from 5 stations and include Wood-Anderson (WA) records.
no. available |
format |
dpi |
color |
|---|---|---|---|
12,223 |
jpeg, tiff |
~400 |
1 bit and grayscale |
Event list and records can be downloaded through SCECDC.
The table below shows stations (3 components) installed before 1936 which data may be available through IRIS DMC. Listed Components shown below are what may be available through SCECDC from 1963-1992.
Region |
Location |
Code |
Latitude |
Longitude |
Timespan |
Components |
|---|---|---|---|---|---|---|
California |
Barrett Dam |
BAR |
32.68005 |
-116.67215 |
1932-2001 |
WA (N), 1-90 (NE,Z) |
Goldstone |
GSC |
35.30177 |
-116.80574 |
1961-2002 |
LP NZE (WWSSN) |
|
Haiwee |
HAI |
36.13664 |
-117.94753 |
1932- 1974 |
||
La Jolla |
LJC |
32.86340 |
-117.25414 |
1932-1952 |
||
Mount Wilson Observatory |
MWC |
34.22362 |
-118.05832 |
1932-2008 |
||
Pasadena |
PAS |
34.14844 |
-118.17117 |
1932-2001 |
WA (2), 1-90, 30-90 (3) |
|
Riverside |
RVR |
33.99351 |
-117.37545 |
1932-2007 |
WA (2), 1-90 (3) |
|
Sand Canyon |
SND |
35.14264 |
-118.30286 |
1933-2002 |
||
Santa Barbara |
SBC |
33.99351 |
-117.37545 |
1932-2001 |
||
Tinemaha |
TIN |
37.05422 |
-118.23009 |
1932-1992 |
WA (2), 1-90 (3) |
Contact#
For more information about this collection, please contact: < blank >
References#
Brodsky, E. & Kanamori, H. (2011). Scans of the Caltech Archives. http://ds.iris.edu/seismoarchives/projects/Caltech_Seismograms.htm (last accessed 26 April 2020)
Goldstein, J. & Roberts, P. (1985). Filming seismograms and related materials at the California Institute of Technology, EOS 66, 737-739.
Hutton, K., Woessner, J., & Hauksson, E. (2020). Earthquake Monitoring in Southern California
for Seventy-Seven Years (1932-2008), Bull. Seismol. Soc. Am. 100, 423-446, doi:10.1785/0120090130.
Photo Credits: Courtesy of the Archives, California Institute of Technology.