SAO - San Andreas Geophysical Observatory

We operate broadband and borehole stations under the network code BK. The Berkeley Digital Seismic Network (BDSN) is a regional network of very broadband and strong motion seismic stations designed to monitor regional seismic activity as well as provide high quality data. The Berkeley borehole stations have borehole geophones or other seismic sensors and may have other geophysical instrumentation.

BARD is our GPS network for monitoring crustal deformation across the Pacific-North America plate boundary and in the San Francisco Bay Area for earthquake hazard reduction studies and rapid earthquake emergency response assessment

Load California Faults

Station Name	SAO (SAOB)
In Operation	1988/01/28 00:00:00 - Present
Latitude
Longitude:
Elevation:	359.8286 meters
Instrumentation	Broadband GPS Other

Site

Location

Site is located at the San Andreas Geophysical Observatory in the Hollister Hills State Vehicle Recreation Area. The BSL first occupied this site in 1966, with a variety of geophysical instrumentation. The digital broadband sensors were installed in 1988.

SAO is a cooperative station with the Advanced National Seismic System.

Network

Berkeley Digital Seismic Network (BK)
Bay Area Regional Deformation Network Network (BARD)

Geology

Jurassic-Cretaceous Gabilan Granite

Borehole Conditions

The vault is a buried steel culvert liner with a set of three isolation doors leading to the interior. The pier is poured concrete. The datalogger and supporting equipment are located in an air-conditioned structure approximately 50' away and connected via underground conduits. The seismometers are thermally insulated with 4" of polyurethane foam.

GPS Monument Description

Poured concrete cylinder with steel reinforcement

Plots & Figures

Seismic Station Pictures

View of SAO equipment building

View of SAO vault

GPS Station Daily Timeseries

GPS Station Pictures

SAOB

Instrumentation

Table of Seismic Instrumentation

	Sensor	Datalogger	SEED Channels	Location
Broadband	Streckeisen STS-1/E300 VBB Feedback Horizontal Seismometer	Q330HR-GFE	BH?,HH?,LH?,VH?	00
	Streckeisen STS-1/E300 VBB Feedback Vertical Seismometer	Q330HR-GFE	BH?,HH?,LH?,VH?	00
Accelerometer	Kinemetrics FBA ES-T Accel. GFE (4 g max 5 v/g)	Q330HR-GFE	HN?	00
Auxiliary	AntennaCurrent	Q330HR-GFE	VE?	00
	ClockPhase	Q330HR-GFE	LC?,VC?	00
	ClockQuality	Q330HR-GFE	LC?,VC?	00
	InputVoltage	Q330HR-GFE	VE?	00
	SystemCurrent	Q330HR-GFE	VE?	00
	SystemTemperature	Q330HR-GFE	VK?	00
	VCOValue	Q330HR-GFE	VC?	00
	CalibrationInput	Q330HR-GFE	LC?	EP
	Humidity	Q330HR-GFE	LI?	EP
	Pressure	Q330HR-GFE	LD?	EP
	Setra Systems Model 270 Barometer	Q330HR-GFE	LD?	EP
	Temperature	Q330HR-GFE	LK?	EP

GPS Instrumentation

	Receiver	Antenna	Radome	-
GPS	SEPTENTRIO POLARX5	SEPTENTRIO SEPCHOKE_B3E6	SPKE	-

Data & Metadata

Waveforms and associated metadata, and GPS data, are available at the Northern California Earthquake Data Center (NCEDC).

Waveform Data

BK Information Directory, including
- List of station locations
- List of available channels
  - Year/month/day format
  - Year,doy format
- Instrument Response
  - SEED format
  - Simplified Responses

Querying the archives
- SeismiQuery at the NCEDC
Download waveform data

GPS Data

Site log: saob.log

Data Type From To
Low-rate raw 08/21/1997 6/9/2009
Low-rate rinex 08/21/1997 present
High-rate raw 6/9/2009 present
High-rate rinex 5/1/2010 present

Data Type	From	To
Low-rate raw	08/21/1997	6/9/2009
Low-rate rinex	08/21/1997	present
High-rate raw	6/9/2009	present
High-rate rinex	5/1/2010	present

Data Quality

Noise Analysis

View more noise plots

GPS Data Quality

Completeness

Data completeness is defined both as "Completeness of observations" and "Cycle slips per observation". "Completeness of Obs." is the number of epochs in the final RINEX file normalized to the expected number. This percentage will go down if time is missing from the RINEX file. "Cycle slips per Obs." is the total number of detected cycle slip normalized to the total number of observations in the RINEX file. This number will increase as the receiver loses lock on satellites more frequently.

Previous Year

Lifetime

Multipath

The effects of multipath on the data are estimated by parameters for L1 and L2 (MP1 and MP2 respectively); see Estey and Meertens (GPS Solutions, 1999) for derivation. The daily value is the RMS of MP1 and MP2 throughout the day and for all satellites. Higher values indicate a greater prevalence and/or strength of multipathing, i.e. objects on the ground are providing multiple reflection pathways from the satellite to antenna.

Previous Year

Lifetime

Signal-to-Noise Ratio

The Signal-to-Noise ratios are the mean values above the QC elevation mask for L1 and L2 respectively.

Previous Year

Lifetime