MHDL - Marin Headlands

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	MHDL (MHLD)
In Operation	2006/05/17 23:00:00 - Present
Latitude
Longitude:
Elevation:	65.9026 meters
Instrumentation	Borehole GPS Other

Site

Location

MHDL is located in the Marin Headlands of the Golden Gate National Recreation Area and was installed under the auspices of the National Park Service. This site is known as SFMAR in the USGS Low Frequency Network.

Although the installation is not complete as far as the data acquisition using the Quanterra datalogger, the USGS satellite system is installed and operational.

Network

Mini Plate Boundary Observatory Network (BK)
Bay Area Regional Deformation Network Network (BARD)

Geology

Franciscan Complex, Cretaceous and Jurassic sandstone

Borehole Conditions

The MiniPBO borehole was installed on 08/06/2002. The strainmeter was installed at 520.6 ft and the seismometer package at 489.2 ft depth. This figure shows the location of equipment in the borehole.

GPS Monument Description

Threaded 5/8" rod cemented into concrete vault, in turn cemented onto bedrock

Plots & Figures

Seismic Station Pictures

View from the Marin Headlands

Installation of strainmeter at MHDL<br>Courtesy of the USGS

Installation of strainmeter at MHDL
Courtesy of the USGS

GPS Station Daily Timeseries

GPS Station Pictures

MHLD

Instrumentation

Table of Seismic Instrumentation

	Sensor	Datalogger	SEED Channels	Location
Geophone	Mark Products L-22 Horizontal Geophone	Q330-GFE	EP?,LP?,SP?	40
	Mark Products L-22 Vertical Geophone	Q330-GFE	EP?,LP?,SP?	40
Auxiliary	BF7	Q330	BT?,LT?,VT?	20
	ElectroMagnetics Inc. BF4 Magnetometer	Q330	BT?,LT?,VT?	20
	AntennaCurrent	Q330-GFE	VE?	40
	ClockPhase	Q330-GFE	LC?,VC?	40
	ClockQuality	Q330-GFE	LC?,VC?	40
	InputVoltage	Q330-GFE	VE?	40
	Paroscientific 8WD Digital Pressure Meter	Q330-GFE	LD?	40
	Sacks 3-component Tensor Strainmeter	Q330-GFE	BS?,HS?,LS?	40
	SystemCurrent	Q330-GFE	VE?	40
	SystemTemperature	Q330-GFE	VK?	40
	VCOValue	Q330-GFE	VC?	40
	CalibrationInput	QEP	LC?	EP
	Humidity	QEP	LI?	EP
	Pinnacle5000	QEP	BA?,LA?	EP
	Pressure	QEP	LD?	EP
	Setra Systems Model 270 Barometer	QEP	LD?	EP
	Temperature	QEP	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: mhld.log

Data Type From To

Low-rate raw --- ---

Low-rate rinex 09/12/2006 present

High-rate raw 9/12/2006 present

High-rate rinex 5/1/2010 present

Data Type	From	To
Low-rate raw	---	---
Low-rate rinex	09/12/2006	present
High-rate raw	9/12/2006	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