Portable Broadband Seismology

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Portable Broadband Seismology
Part 2 Functions of an Instrument Center

• Jakarta, Indonesia
• May 11-13, 2006
• Bruce Beaudoin
• Marcos Alvarez

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PASSCAL

• Program for Array Seismic Studies of the
  Continental Lithosphere

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Outline

• Facility overview
• Equipment Supported
• Experiments Supported
• Inventory
• Equipment Maintenance and QC
• User Services
• Polar Support

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PASSCAL

• A facility for academic research in seismology.
  Funded by the National Science Foundation and the
  Department of Energy.

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Instrument Use

• Available to researchers for non-commercial use
• PI must agree to the following conditions
• All data must be released to the IRIS Data
  Management center within 2 years of completion of
  field work
• PI must receive proper training at the Instrument
  Center
• PI responsible for all shipping and customs cost

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PASSCAL Facilities Core

• PASSCAL Instrument Center, Socorro
• Main support and development
• 13.5 FTEs
• Active Source Support Center, UTEP
• Use of 400 instruments and field support
• 1.5 FTEs
• Telemetered Array Support Center, UCSD
• Telemetry support for field experiments
• 1.5 FTEs

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PASSCAL Facilities AOF

• Array Operations Facility at PASSCAL Instrument
  Center, Socorro
• Main support and development for USArray
  Transportable and Flexible Arrays
• 9.5 FTEs
• Transportable Array Coordinating Office
• Field logistics support for TA
• 4 FTEs

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EquipmentInventory
Item Current 06
Reftek R130 460
Quanterra Q330 370
Multi-channel 4 4
Texans (125) 828
Texans (125A) 150
Broadband Sensor 439 22
Short Period Sensor 264
High Frequency Sensor 419
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Equipment Inventory3-channel dataloggers
Quanterra Q330
RefTek RT130
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Equipment Inventory1-channel datalogger
RefTek RT125
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Equipment InventorySeismometers
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Equipment InventoryBroadband Seismometers
Guralp CMG-3T
Streckeisen STS-2
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Equipment InventoryIntermediate Period
Seismometers
CMG-40T 30s active feedback
CMG-ESP 30s active feedback
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Equipment InventoryShort Period Seismometers
L4C 1Hz
Teledyne GS-13 1Hz 1 Element/Housing
L22 2Hz
Passive Sensors
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Equipment InventoryHigh Frequency Seismometers
L28
L40 Strings
4.5 to 40Hz Single component Strings of single
component 3-Component
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Seismic Experiments

• Utilize sound waves propagating through the earth
  to create images of the earths bulk properties
  (e.g. velocity, attenuation, travel-time
  anomalies).
• Two basic sources for sound waves
• Passive (natural sources).
• Active Source (man made).

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Experiment Support
Experiment Type Number for 2006
Broadband 25
Short Period 15
RT125 (Active Source) 6
Multi-channel 6
Total 52
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Characteristics of a Passive Experiment

• Sources include earthquakes, ambient noise,
  tides, magma.
• Long term (months to years)
• Broad spacing (regional to global)
• Low frequency (.001-1Hz)
• Typically a few to tens of instruments.

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Sources for Passive Experiments
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Broadband StationsSince 2000
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Namche Barwa, TibetMeltzer, Sol, Zurek, Zeitler
Receiver functions indicate the thinnest crust is
associated with the region of highest
exhumation. Shear wave splitting indicates a
fast direction consistent with surface tectonic
features. Authors argue for a strong lower crust.
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May 10, 2003 Eruption of Anatahan Volcano,
Mariana Islands

• PASSCAL station installed 4 days prior to
  eruption
• Volcano-tectonic events start to occur 5 hrs
  before eruption and significantly increase 1 hrs
  prior.
• Tilt is reconstructed from STS-2 horizontal
  signal
• Pozgay Wiens

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Active Source Experiments

• Sources include explosions, airguns, sledge
  hammers, vibrators
• Short term (days to weeks)
• High frequency (2-80Hz)
• Hundreds of instruments
• Closely spaced

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Some Sources
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Celebration 2000Keller et al.
147 Shots 1230 Stations 5400 km
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Hill Air Force Base, Utah Gao et al.
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RAMPRapid Array Mobilization Policy

• 2002 Denali 7.9M, over 30,000 aftershocks
  recorded Ruppert et al.

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Inventory Database

• PASSCAL maintains an extensive inventory of all
  equipment
• The inventory provides two main purposes
• Instrument tracking
• Maintenance history
• All equipment is barcoded and entered into an
  in-house developed database driven by mysql

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PASSCAL Inventory Maintenance database
Interface for searching inventory
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PASSCAL Inventory Maintenance database
Tracks shipments by experiment code
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PASSCAL Inventory Maintenance database
Tracks inventory items assigned to experiments
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PASSCAL Inventory Maintenance database
Maintenance records
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Hardware Maintenance and QC Dataloggers

• Function test all DAS prior to shipment
• Maintain maintenance records in an electronic
  database
• Test and upgrade firmware when necessary
• Monitor DAS running in house for unusual behavior

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Hardware Maintenance and QC Seismometers

• All broadband seismometers are function tested
  when they arrive from an experiment.
• All broadband seismometer are pier tested for 4-7
  days and the data are compared to a reference
  seismometer prior to deployment.
• Comparisons are made of
• Polarity
• Amplitude
• Power Spectral Density
• Typical problems include
• pivot pings
• Sensitivity
• imbalanced masses

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User Services
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Data QC Software

• PASSCAL develops and maintains software to
  extract data from the dataloggers, perform
  in-field quality control, and manipulate the
  waveforms into archive formats (SEGY, SEED).
• http//www.passcal.nmt.edu
• ftp.passcal.nmt.edu

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Troubleshooting

• PASSCAL provides email and phone support for our
  users both during and after their field
  deployment. Staff are available to analyze
  specific problems and frequently recognize
  potential problems in our lab before they
  manifest in-situ.
• Typically there are over 400 broadband and
  short-period PASSCAL stations deployed at any
  given time.

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Data Archiving Support

• PASSCAL acts as an intermediary between the PI
  and the DMC
• Check completeness of data submitted to PASSCAL
• Flag waveforms w/ questionable timing
• Fix mseed headers
• Verify SEED Format
• Ensure agreement between dataless and waveforms
• Check completeness of data submitted to DMC

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Data Delivery Services
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PASSCALs Support of Polar Research
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Antarctic Experiment Support

• 25 Experiments supported since 1990
• Most experiments are multi-year (e.g over-winter)
• 2005-2006 supporting 6 Antarctic experiments (62
  stations snow streamer)
• Broadband, active-source, glaciology

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Equipment Limitations

• Q330 - Fully specd to -40C
• Baler - -40C (not media)
• Disk Drive - -20C
• Flash Media - -55C
• STS-2 0-40C
• 3T - -10C-65C,
• cabling -20C
• power controller -20C

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Additional Resources

• Environmental Chamber - 27 cu. ft., -70C to 120C
• 60 - channel snow streamer80 takeouts, 7
  12-takeout cables, Geode adapters.
• Solid state disks - 4 9 GB
• Wind generators - 10