The initial characterization period ended in 1997. During that period,
the NHFN sensors provided signals to on-site, stand-alone Quanterra Q730
and RefTek 72A-07 dataloggers, and manual retrieval and download of
data tapes was required. Also in that year, the long-term monitoring
phase of the project began, involving the installation of 24-bit data
acquisition and communication platforms and data telemetery to the BSL
archives for a backbone of the initial NHFN stations.
Over the years, CalTrans has provided additional support
for the upgrade of two non-backbone sites to backbone operational status and
for the addition of several new sites to the monitoring back-bone. These
expansion efforts are ongoing. Also since the transition to the long-term
monitoring phase, the 5 stations of the MPBO project have been folded into
the NHFN.
Of the 28 stations now considered part of the NHFN history, 14 of the
stations are currently operational, with telemetered data streams
flowing continuously into the BSL's BDSN processing stream with
subsquent archival in the Northern California Earthquake Data Center
(NCEDC) archive. These include the 5 MPBO sites. Nine of the original
28 are non-backbone stations that have not been upgraded to continuous
telemtry. Though collection of data from these sites has been
discontinued, their borehole sensor packages are still in place (having
been grouted in), and efforts to find funding for upgrade of these sites
with Quanterra Q4120, Q730 or Q330 dataloggers and continuous telemetry
continues. The remaining 5 sites are in the process of being added to
the NHFN backbone. Four of the sites have been drilled and
instrumented and are awaiting installation of their electronics and
infrastructures. Equipment has been purchased for the 1 remaining
site, which is awaiting final land-use agreement from the Regional Parks
district and drilling by CalTrans.
Installation/Instrumentation:
The NHFN Sensor packages are generally
installed at depths ranging between 100 and 200 m, the non-backbone
non-operational Dumbarton bridge sites being exceptions with
sensors at multiple depths (Table 3.5).
The five former MPBO sites that are now part of the NHFN have
3-component borehole geophone packages. Velocity measurements for the
MPBO sites are provided by Mark Products L-22 2 Hz geophones (Table
3.6). All the remaining backbone and non-backbone NHFN
sites have six-component borehole sensor packages. The six-component
packages were designed and fabricated at LBNL's Geophysical Measurement
Facility and have three channels of acceleration, provided by
Wilcoxon 731A piezoelectric accelerometers, and three channels of
velocity, provided by Oyo HS-1 4.5 Hz geophones.
The 0.1-400 Hz Wilcoxon
accelerometers have lower self-noise than the geophones above about
25-30 Hz, and remain on scale and linear to 0.5 g. In tests performed
in the Byerly vault at UC Berkeley, the Wilcoxon is considerably
quieter than the FBA-23 at all periods, and is almost as quiet as the
STS-2 between 1 and 50 Hz.
All 14 NHFN backbone sites have Quanterra dataloggers with
continuous telemetry to the BSL. Signals from
these stations are digitized at a variety of data rates up to 500 Hz at
24-bit resolution (Table 3.7).
The dataloggers employ causal FIR filters at high data rates and
acausal FIR filters at lower data rates.
Data Rates and Channels:
Because of limitations in telemetry bandwidth and disk storage, 8 of
the 9 (excluding VALB) six-component NHFN stations transmit one channel
of geophone data continuously (i.e., their vertical geophone channels)
and an additional 3 channels of triggered data in 90 sec. snippets. A
Murdock, Hutt, and Halbert (MHH) event detection algorithm (Murdock and Hutt, 1983) is operated independently at each station on
500 sps data for trigger determinations. Because of they are quieter,
the 3 triggered channels are taken from the Wilcoxon accelerometers
when possible. However, there is a tendency for these powered sensors
to fail and in such cases, geophone channels are substituted for the
failed accelerometers. Station VALB also transmits data from only 4
channels; however, all channels are transmited continuously.
Continuous data for all channels at reduced rates (20
and 1 sps) are also transmitted to and archived at the BSL. The five
MPBO sites transmit their 3-component continuous geophone data streams
at 100, 20 and 1 sps, which are also archived at BSL.
Table 3.5:
Stations of the Hayward Fault Network. Each HFN station is listed with
its station code, network id, location, operational dates, and site
description. The latitude and longitude (in degrees) are given in the
WGS84 reference frame. The elevation of the well head (in meters) is
relative to the WGS84 reference ellipsoid. The overburden is given in
meters. The start dates indicate either the upgrade or installation
time.
The abbreviations are:
BB - Bay Bridge;
BR - Briones Reserve;
CMS - Cal Memorial Stadium;
CB - Carquinez Bridge;
DB - Dumbarton Bridge;
MPBO - mini-Plate Boundary Observatory;
RFS - Richmond Field Station;
RSRB - Richmond-San Rafael Bridge;
SF - San Francisco;
SMB - San Mateo Bridge;
SMC - St. Mary's College;
and, YB - Yerba Buena.
The * for station PINB indicates that this station name has been requested
but has not yet been approved and may change. The * in the Date column
indicates the stations that have recorded data from an earlier period of
manually retrieved tapes, but that are currently
off-line.
| Code |
Net |
Latitude |
Longitude |
Elev (m) |
Over (m) |
Date |
Location |
| VALB |
BK |
38.1215 |
-122.2753 |
-24 |
155.8 |
2005/11 - current |
Napa River Bridge |
| PETB |
BK |
38.1189 |
-122.5011 |
-30 |
113 |
in progress |
Petaluma River Bridge |
| CRQB |
BK |
38.05578 |
-122.22487 |
-25 |
38.4 |
1996/07 - current |
CB |
| HERB |
BK |
38.01250 |
-122.26222 |
-25 |
217.9 |
2000/05 - current |
Hercules |
| PINB* |
BK |
38.0113 |
-122.3653 |
tbd |
tbd |
in progress |
Point Pinole |
| BRIB |
BK |
37.91886 |
-122.15179 |
219.7 |
108.8 |
1995/06 - current |
BR, Orinda |
| RFSB |
BK |
37.91608 |
-122.33610 |
-27.3 |
91.4 |
1996/01 - current |
RFS, Richmond |
| CMSB |
BK |
37.87195 |
-122.25168 |
94.7 |
167.6 |
1994/12 - current |
CMS, Berkeley |
| SMCB |
BK |
37.83881 |
-122.11159 |
180.9 |
3.4 |
1997/12 - 2007/06 |
SMC, Moraga |
| SM2B |
BK |
37.8387 |
-122.1102 |
200 |
150.9 |
2007/06 - current |
SMC, Moraga |
| SVIN |
BK |
38.03325 |
-122.52638 |
-21 |
158.7 |
2003/08 - current |
MPBO, St. Vincent's school |
| OHLN |
BK |
38.00742 |
-122.27371 |
-0 |
196.7 |
2001/07 - current |
MPBO, Ohlone Park |
| MHDL |
BK |
37.84227 |
-122.49374 |
94 |
160.6 |
2006/05 - current |
MPBO, Marin Headlands |
| SBRN |
BK |
37.68562 |
-122.41127 |
4 |
157.5 |
2001/08 - current |
MPBO, San Bruno Mtn. |
| OXMT |
BK |
37.4994 |
-122.4243 |
209 |
194.2 |
2003/12 - current |
MPBO, Ox Mtn. |
| BBEB |
BK |
37.82167 |
-122.32867 |
-31 |
150.0 |
2002/05 - current |
BB, Pier E23 |
| E17B |
BK |
37.82086 |
-122.33534 |
|
160.0 |
1995/08 - current * |
BB, Pier E17 |
| E07B |
BK |
37.81847 |
-122.34688 |
tbd |
134.0 |
1996/02 - current * |
BB, Pier E7 |
| YBIB |
BK |
37.81420 |
-122.35923 |
-27.0 |
61.0 |
1997/12 - current * |
BB, Pier E2 |
| YBAB |
BK |
37.80940 |
-122.36450 |
|
3.0 |
1998/06 - current * |
BB, YB Anchorage |
| W05B |
BK |
37.80100 |
-122.37370 |
tbd |
36.3 |
1997/10 - current * |
BB, Pier W5 |
| W02B |
BK |
37.79120 |
-122.38525 |
-45 |
57.6 |
2003/06 - current |
BB, Pier W2 |
| SFAB |
BK |
37.78610 |
-122.3893 |
|
0.0 |
1998/06 - current * |
BB, SF Anchorage |
| RSRB |
BK |
37.93575 |
-122.44648 |
-48.0 |
109.0 |
1997/06 - current * |
RSRB, Pier 34 |
| RB2B |
BK |
37.93 |
-122.41 |
tbd |
133.8 |
2003/07 - current * |
RSRB, Pier 58 |
| SM1B |
BK |
37.59403 |
-122.23242 |
|
298.0 |
not recorded |
SMB, Pier 343 |
| DB3B |
BK |
37.51295 |
-122.10857 |
|
1.5 |
1994/09 - 1994/11 |
DB, Pier 44 |
| |
|
|
|
|
62.5 |
1994/09 - 1994/09 |
|
| |
|
|
|
|
157.9 |
1994/07 - current * |
|
| DB2B |
BK |
37.50687 |
-122.11566 |
|
|
1994/07 - current * |
DB, Pier 27 |
| |
|
|
|
|
189.2 |
1992/07 - 1992/11 |
|
| DB1B |
BK |
37.49947 |
-122.12755 |
|
0.0 |
1994/07 - 1994/09 |
DB, Pier 1 |
| |
|
|
|
|
1.5 |
1994/09 - 1994/09 |
|
| |
|
|
|
|
71.6 |
1994/09 - 1994/09 |
|
| |
|
|
|
|
228.0 |
1993/08 - current * |
|
| CCH1 |
NC |
37.7432 |
-122.0967 |
226 |
|
1995/05 - current |
Chabot |
| CGP1 |
NC |
37.6454 |
-122.0114 |
340 |
|
1995/03 - current |
Garin Park |
| CSU1 |
NC |
37.6430 |
-121.9402 |
499 |
|
1995/10 - current |
Sunol |
| CYD1 |
NC |
37.5629 |
-122.0967 |
-23 |
|
2002/09 - current |
Coyote |
| CMW1 |
NC |
37.5403 |
-121.8876 |
343 |
|
1995/06 - current |
Mill Creek |
|
Table 3.6:
Instrumentation of the HFN as of 06/30/2007. Every HFN downhole
package consists of co-located 3-component geophones and
accelerometers, with the exception of MPBO sites which have only
3-component geophones and are
also collecting tensor strainmeter data. Six HFN sites (5 of the SHFN and
1 of the NHFN) also have dilatometers (Dilat.). Currently, 14 NHFN sites
have Quanterra dataloggers with continuous telemetry to the BSL. The
remaining backbone sites are either still being developed with support
from Caltrans or are being upgraded to Quanterra dataloggers. The 5
SHFN sites have Nanometrics dataloggers with radio telemetry to the
USGS. The orientation of the sensors (vertical - Z, horizontals - H1
and H2) are indicated where known or identified as "to be determined"
(TBD).
| Site |
Geophone |
Accelerometer |
Z |
H1 |
h2 |
datalogger |
Notes |
Telem. |
| VALB |
Oyo HS-1 |
Wilcoxon 731A |
TBD |
TBD |
TBD |
Q330 |
|
FR |
| PETB |
Oyo HS-1 |
Wilcoxon 731A |
TBD |
TBD |
TBD |
TBD |
|
TBD |
| CRQB |
Oyo HS-1 |
Wilcoxon 731A |
-90 |
251 |
341 |
Q4120 |
|
FR |
| HERB |
Oyo HS-1 |
Wilcoxon 731A |
-90 |
TBD |
TBD |
Q4120 |
|
FR |
| PINB |
Oyo HS-1 |
Wilcoxon 731A |
TBD |
TBD |
TBD |
TBD |
|
TBD |
| BRIB |
Oyo HS-1 |
Wilcoxon 731A |
-90 |
79 |
349 |
Q4120 |
Acc. failed, Dilat. |
FR |
| RFSB |
Oyo HS-1 |
Wilcoxon 731A |
-90 |
256 |
346 |
Q4120 |
|
FR |
| CMSB |
Oyo HS-1 |
Wilcoxon 731A |
-90 |
19 |
109 |
Q4120 |
|
FR |
| SMCB |
Oyo HS-1 |
Wilcoxon 731A |
-90 |
76 |
166 |
Q4120 |
Posthole |
FR |
| SM2B |
Oyo HS-1 |
Wilcoxon 731A |
TBD |
TBD |
TBD |
Q4120 |
|
FR |
| SVIN |
Mark L-22 |
|
-90 |
298 |
28 |
Q4120 |
Tensor. |
FR/Rad. |
| OHLN |
Mark L-22 |
|
-90 |
313 |
43 |
Q4120 |
Tensor. |
FR |
| MHDL |
Mark L-22 |
|
-90 |
TBD |
TBD |
Q4120 |
Tensor. |
FR |
| SBRN |
Mark L-22 |
|
-90 |
347 |
77 |
Q4120 |
Tensor. |
FR |
| OXMT |
Mark L-22 |
|
-90 |
163 |
253 |
Q4120 |
Tensor. |
FR |
| BBEB |
Oyo HS-1 |
Wilcoxon 731A |
-90 |
TBD |
TBD |
Q4120 |
Acc. failed |
Radio |
| E17B |
Oyo HS-1 |
Wilcoxon 731A |
-90 |
TBD |
TBD |
None at present |
|
|
| E07B |
Oyo HS-1 |
Wilcoxon 731A |
-90 |
TBD |
TBD |
None at present |
|
|
| YBIB |
Oyo HS-1 |
Wilcoxon 731A |
-90 |
257 |
347 |
None at present |
Z geop. failed |
FR/Rad. |
| YBAB |
Oyo HS-1 |
Wilcoxon 731A |
-90 |
TBD |
TBD |
None at present |
|
|
| W05B |
Oyo HS-1 |
Wilcoxon 731A |
-90 |
TBD |
TBD |
None at present |
|
|
| W02B |
Oyo HS-1 |
Wilcoxon 731A |
-90 |
TBD |
TBD |
Q4120 |
|
Radio |
| SFAB |
None |
LLNL S-6000 |
TBD |
TBD |
TBD |
None at present |
Posthole |
|
| RSRB |
Oyo HS-1 |
Wilcoxon 731A |
-90 |
50 |
140 |
None at present |
2 acc. failed |
FR |
| RB2B |
Oyo HS-1 |
Wilcoxon 731A |
-90 |
TBD |
TBD |
None at present |
1 acc. failed |
|
| SM1B |
Oyo HS-1 |
Wilcoxon 731A |
-90 |
TBD |
TBD |
None at present |
|
|
| DB3B |
Oyo HS-1 |
Wilcoxon 731A |
-90 |
TBD |
TBD |
None at present |
Acc. failed |
|
| DB2B |
Oyo HS-1 |
Wilcoxon 731A |
-90 |
TBD |
TBD |
None at present |
|
|
| DB1B |
Oyo HS-1 |
Wilcoxon 731A |
-90 |
TBD |
TBD |
None at present |
Acc. failed |
|
| CCH1 |
Oyo HS-1 |
Wilcoxon 731A |
-90 |
TBD |
TBD |
Nanometrics HRD24 |
Dilat. |
Radio |
| CGP1 |
Oyo HS-1 |
Wilcoxon 731A |
-90 |
TBD |
TBD |
Nanometrics HRD24 |
Dilat. |
Radio |
| CSU1 |
Oyo HS-1 |
Wilcoxon 731A |
-90 |
TBD |
TBD |
Nanometrics HRD24 |
Dilat. |
Radio |
| CYD1 |
Oyo HS-1 |
Wilcoxon 731A |
-90 |
TBD |
TBD |
Nanometrics HRD24 |
Dilat. |
Radio |
| CMW1 |
Oyo HS-1 |
Wilcoxon 731A |
-90 |
TBD |
TBD |
Nanometrics HRD24 |
Dilat. |
Radio |
|
Subsections
Berkeley Seismological Laboratory
215 McCone Hall, UC Berkeley, Berkeley, CA 94720-4760
Questions or comments? Send e-mail: www@seismo.berkeley.edu
© 2007, The Regents of the University of California
