USGS Professonal Paper 1096 - IRIS

ALASKA
Sitka, AI(
GENERAL INFORMATION
Operated by:
Address:
U.S. Geological Survey
u.s. Geological Survey
Box 158
Sitka, AI( 99835
Telephone: 907-747-3332
Address to obtain records:
National Geophysical .nd Solar-Terrestrial Data Center
NOAA/EnS, Do2
Boulder, CO 80302
SITE INFORMATION
Code
Station name
Latitude Longitude Elev Date Date Founda tion; geologiC
(degN.) (deg W.) (meters) opened closed
.g.
BID Biorka------------------ 56.8517 135.5583 61 6/08/67 5/70 Hornblende-biotite granodiorite;
Cretaceous.
SIT Sitka------------------- 57.0569 135.3244
l'
1940 Open-- Sitka Graywacke; L3Le jUrass1c and
Early Cretaceous.
INSTRUMENTATION
Seismometer Galvo Typ. Magnification
Code Typ. Component To(sec) Tg(sec) recording .t T
0
Remarks
BID Geotech S-13--------- Z 1.0 0.2 Helicorder 50 K Telemetered to SIr and
PMR.
SI'I' Eegjoff 4681A-------- Z 1.0 .2 Pen and ink 25 K Telemetered to PMR.
Weuner--------------- NS,EW 7.0 15 .0 Photo paper Uncalibrateo ---
Tilling system: Sprcognether T5-100 Crystal Chronomete r.
System response curves: SIT--see figure 4, p. 364.
SHORT HISTORY
Recording in Sitka began in 1904 at the Astronomical Observatory using a two-component horizontal Bosch-Omori. Wenner
horizontal components replaced the Bosch-OmOri in 1932; they were refurbished in 1941-42. Th. instruments were moved to the
PI'@UlDt SII Jocatjon j[l September 19!tO ~ Wilson-Lamison short-~eriod vertical instrument was added in 1956. Th. Benioff
mentioned above was installed in January 1972 and is recorded concurrently at the Alaska Tsunami warn1ng Center.
BIO was founded in 1967 to enhance the regional capabilities of Sitka, but it proved to be too noisy.
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