Analysis of Seismo-Acoustic Emission from Ice Fracturing Events During SIMI'94
Abstract
In this thesis the analysis of natural ice events was carried out based on direct measurements of ice-borne seismo-acoustic waves generated by ice fracturing processes. The data analyzed in this thesis were collected during the Sea Ice Mechanics Initiative experiment in the spring of 1994 in the Central Arctic. One of the contributions of this thesis was the determination of the polarization characteristics of elastic waves using multicomponent geophone data. Polarization methods are well known in seismology, but they have never been used for ice event data processing. The identification of source mechanisms was based on the radiation patterns of the events. This identification was carried out through the analysis of the seismo-acoustic emission of natural ice events in the ice sheet. After identification of the events, the estimation of the parameters of fault processes in Arctic ice was carried out. Stress drop, seismic moment and the type of ice fracture were determined using direct near-field measurements of seismo-acoustic signals generated by ice events. During data processing the new phenomenon was discovered: edge waves, which are waves propagating back and forth along a newly opened ice lead. The propagation characteristics of these waves were determined using seismic wave number estimation techniques.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 01, 1999
- Accession Number
- ADA369274
Entities
People
- Yuriy V. Dudko
Organizations
- Massachusetts Institute of Technology