On the CTBT Monitoring Potential of Using LG-Phase Arrival Times at Local and Regional Distance Ranges

Abstract

The prominent Lg wave is nearly always observed at local and regional distances. It is a surface wave propagating with almost constant group velocity around 3.5 km/s over a vast distance range of hundreds to thousands of kilometers. Thus, Lg propagation should in principle simplify epicenter location schemes, based on relative travel time equations. In our ongoing efforts to accomplish this we computed Hilbert or STA-envelopes and showed that in many recordings from Fennoscandia and Central Europe the Lg group velocities measured using the envelope peak arrival times are remarkably consistent. However, they tightly concentrate around 3.4 km/sec for the Baltic shield of Fennoscandia and around 3.2 km/sec for the much younger crust of Central Europe. These Lg picks were subsequently used in the Pinsky (2008) relative time location algorithms of "group beamforming" and "probabilistic beamforming" for refined epicenter locations in Balticum.

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Document Details

Document Type
Technical Report
Publication Date
Sep 01, 2008
Accession Number
ADA516244

Entities

People

  • Eystein S. Husebye
  • Tatiana S. Matveeva
  • Vladimir I. Pinsky
  • Yury V. Fedorenko

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Algorithms
  • Central Europe
  • Computational Science
  • Earth Models
  • Earthquakes
  • Epicenters
  • Equations
  • Europe
  • Explosions
  • Grids
  • Ground Based
  • Group Velocity
  • Nuclear Explosions
  • Surface Waves
  • Travel Time
  • Wave Propagation
  • Waves

Readers

  • Seismology
  • Systems Analysis and Design