USGS Professonal Paper 1096 - IRIS

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PUERTO RICO--Continued
Cayey, PR
INSTRUMENTATION--Continued
Seismometer Galvo Typ. Magnification Remarks
Code Typ. Component T o (sec) Ig(sec) recorihng .E I
0
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SJP: Wenner--------------- NS,EW 12.0 Paper
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Benioff-------------- Z 1.04 .5 --do-------
VQS: Bosch-Omori---------- NS,EW 25.0
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Timing system:
IOOIB .nd IRIG-E signals recorded directly with
• Geotech TG-110 used " • backup.
System response curves: SJGnsee tl-gure I, p. 363. All Geotech S-13 syslemsnsee hgute 10, p. 306.
SHORT HISTORY
This network i" used principa 11 y to determine th, regional .nd local seismicity of Puerto Rico .nd to assess the seismic
hazard.
The S.n Juan Magnetic Observatory WO" established by the USC&GS in 1903, first ot VQS .nd then .t SJP.
VQS was established in September 1903 at Fort Isabel Segunda, Vieques Island, Puerto Rico (1S008.9' N. , 65°26.4' W. elevation,
40 m) . In ilardi 1907 it .. as ma"ed Lo 18 0 eS.8' II., 65°26.9' 11., (de. atiaR 29 m) . This statitOHl pas discontinued on
December I, 1924, • nd the instruments were moved to SJP .
SJP was equipped with two Bosch-Omori seismographs, 8-sec periods, which began operating in January 1926. A destructive
hurricane in September 1928 rendered the station inoperative; it resumed operation in November 1930 with two horizontal Wenner
instruments. In November 1950 the vertical Benioff WO" added.
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