A Long-Period Noise Study at Murphy Dome, Alaska (LRSM Site FB-AK and ALPA Site 3-4)

Abstract

Long-period signals and noise samples recorded at Murphy Dome, Alaska, on standard LRSM instruments and the Geotech triaxial seismometer were subjected to spectral analysis. System noise tests showed that recorded seismic noise was limited to a band from .02 to 0.3 cps. Spectra representing many recording periods between January and August 1969 revealed the background noise to be of variable character and the RMS to range from 2.5 millimeters to 5.2 millimeters on a trace magnified 100,000 times with the standard LRSM system response. Due to its location at depth the triaxial instrument significantly reduced background noise on horizontal components caused by atmospheric pressure changes. Coherence between triaxial components of motion and corresponding LRSM components was excellent for most signals analyzed.

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Document Details

Document Type
Technical Report
Publication Date
Jan 06, 1970
Accession Number
AD0864172

Entities

People

  • D. H. Von Seggern

Organizations

  • Teledyne Technologies

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Air Force
  • Background Noise
  • Barometric Pressure
  • Confidence Limits
  • Contracts
  • Export Controls
  • Frequency
  • Frequency Bands
  • Government (Foreign)
  • Power Levels
  • Power Spectra
  • Rayleigh Waves
  • Recording Systems
  • Seismographs
  • Seismometers
  • Surface Waves
  • Waves

Fields of Study

  • Environmental science

Readers

  • Acoustics.
  • Seismology