GASB - Alder Springs, CA, USA

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	GASB (GASB)
In Operation	2005/09/22 00:00:00 - Present
Latitude
Longitude:
Elevation:	1354.8 meters
Instrumentation	Broadband GPS

Site

Location

The site is located at Alder Springs, CA, USA.

In addition to the UC Berkeley broadband and strong-motion sensor, this area is home to a short-period sensor operated by the California Department of Water Resources.

Support for GASB was provided by National Tsunami Hazard Program and the Governor's Office of Emergency Services as part of the California Integrated Seismic Network.

Network

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

Geology

TBD

Borehole Conditions

The instruments are located in a steel and concrete vault benched into a gentle hillside and covered with soil overburden. The concrete pier is covered with 4" of insulation on the sides and 8" of insulation on the top. The datalogger and supporting equipment are in an adjacent room.

GPS Monument Description

Post fixed into the concrete that surrounds seismic vault. Post is reinforced by a concrete cylinder and three welded legs. The ends of the three legs were driven into the ground and filled in with cement.

Plots & Figures

Seismic Station Pictures

Construction at GASB

GASB vault under construction

GPS Station Timeseries

Time series processing at the BSL

Last year	Clean	Clean & detrended	Raw	Raw & detrended
Lifetime	Clean	Clean & detrended	Raw	Raw & detrended
Text file (final results only)	Clean		Raw

GPS Station Pictures

Instrumentation

Table of Seismic Instrumentation

	Sensor	Datalogger	SEED Channels	Location
Broadband	Streckeisen STS-2 VBB Tri-Axial Seismometer	Q330HR-GFE	BH?,HH?,LH?,VH?	00
Accelerometer	Kinemetrics FBA ES-T Accel. (4 g max 5 v/g)	Q330HR-GFE	HN?	00
	Receiver	Antenna	Radome	-
GPS	Topcon Net-G3A	Topcon Choke-Ring	SCIGN Tall	-
	Sensor	Datalogger	SEED Channels	Location
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

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
- NetDC Request Form
Download waveform data

GPS Data

Site log: gasb.log

Data Type From To
Low-rate raw --- ---

Low-rate rinex 6/17/2011 present

High-rate raw 6/17/2011 present

High-rate rinex 6/17/2011 present

Data Type	From	To
Low-rate raw	---	---
Low-rate rinex	6/17/2011	present
High-rate raw	6/17/2011	present
High-rate rinex	6/17/2011	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.