XSC1
Slack Canyon Creepmeter

On March 6, 1997, the transducer for this instrument
was replaced. The transducer had started to fail in
early 1997. In addition, critical micrometer measurements
were lost. The tie between the measurements prior
to March 6, 1997 is tentative; users should treat
the data gap as a potential offset.

Around Jan 23, 2007, the DCP and electronics amplifier were
changed. Noted that the old electronics, for some reason
"saturated" or 'hit the rail' when output of electronic exceeded
about 3.7 volts (or the micrometer exceeded 20 mm or so).
Inspection of micrometer log reveals that during operation of
this instrument, that has never happened. With new DCP
and electronics, telemetry voltage range now 0-5v; scale factor 
is now 119 counts(mv) per mm fault slip (creep).

July 1, 2011 -- Recalculate scale factor base upon comparison of
digital measurements with aperiodic micrometer measurements. scale factor
changed by 4.5%.  This is reflected in the archival data.

Possible times of Offsets:
N 201401292250 Wire reset (AS)
T 201403011900 Rain storm effect (AS)
N 201409172230 Wire reset (AS)
T 201502090410 Rain response (AS)
T 201502091240 Ditto (AS)
N 201504222040 Wire Reset (AS)
N 201510082300 Wire Reset (AS)
N 201605252000 Wire Reset (AS)
N 201705032030 Wire Reset (AS)
N 201804252110 Ditto
N 201904102240 Wire reset (TE) 
S N 2021j1662200  Wire reset micrometer offscale; wire reset by 35.71 mm -- 40.08 mm creep

Site off-line since Nov 18, 2022

For more information, please consult:
Open-File Report 2024-1011, “Summary of Creepmeter Data from 1980 to 2020—Measurements Spanning the Hayward, Calaveras, and San Andreas Faults in Northern and Central California” https://pubs.usgs.gov/publication/ofr20241011

and
Open File Report 89–650, "Catalog of creepmeter measurements in California from 1966 through 1988" https://pubs.usgs.gov/publication/ofr89650

Many people have contributed to this project including:
Roger Bilham
Robert Burford
Sandy Schulz
Andy Snyder
Kate Breckinridge
Todd Erickson
Rich Liechti
Vince Keller
John Langbein

For questions, contact John Langbein (langbein@usgs.gov)