CWN1

Cienegia Winery

Drift between micrometer and electronic telemetried data may be due to
potentiometer problem. 


June 4, 2003;  site visit;  tighten bolts holding 'Pacific plate'
anchor; may have displaced instrument by 2 mm as revealed by telemetry;
Micrometer measurements were not recorded to cover possible offset; JL
used telemetry results to infer micrometer reading.

Oct 5, 2004:  Noted that bolts securing creepmeter to 'Pacific plate'
had sheared.

Mar 9, 2005;  Replaced bolts and reattached creepmeter to 'Pacific Plate'.

Inference is that data between Mid Aug, 2003 and March 9, 2005 are bad
and are deleted.  

May 2008 swap-out electronics and DCP for a new version; Telemetry 
voltage range still 0-5v with Cal-Tech potentiometer setup; scale factor is 
now 134 counts(mv) per mm fault slip (creep).

April 20, 2012 --  Noticed that creepmeter was "bumped" by Winery
operations and shaft was bent; Site visit removed bend but may have
created an artifical offset in the micrometer data.

March 19, 2013 -- Rod had to be replaced, but may have
created an artifical offset in the micrometer data.

Feb 16, 2022 --  removed original poteniometer sensor and replaced with a
LVDT with a 1/2 inch range.

N 201401232240 Rod reset (AS)
N 201504212130 Ditto
N 201611012140 Rod reset (AS)
N 201711080050 Rod reset (AS/TE)
N 201711080100 Rod reset (AS/TE)
N 2020j2472215 Rod reset and Change resolution and timing interval
N 2020j2632230 site visit to fix grounding problem
N 202201282300 site visit
N 2022j0341800 site visit to repair broken bolts
N 2022j0472110 site visit to change sensor from poteniometer to lvdt
N 202202232000 site visit to change lvdt
N 2022j0571800 site visit to improve temperature compensation
N 2022j0891930 site visit to improve temperature compensation


Interval  July 1 2013 to Feb 16, 2022 --  Rescaled telemetry data of creep
to better match the micrometer measurements -- This assumes that the calibration
changed over time, but with the aperiodic micrometer measurements, that serves as
a means to re-calibrate the resistive sensor.

CWC3

Creepmeter is more or less unreliable since 2000; bolts holding the
creepmeter to floor have stripped.

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