A two-step procedure for calculating earthquake hypocenters at Augustine Volcano: Chapter 7 in The 2006 Eruption of Augustine Volcano, Alaska
Links
- More information: USGS Index Page (html)
- Larger Work: This publication is Chapter 7 of The 2006 eruption of Augustine Volcano, Alaska
- Download citation as: RIS | Dublin Core
Abstract
This chapter describes a two-step technique for determining earthquake hypocenters at Augustine Volcano. The algorithm, which was originally developed in the mid-1970s, was designed both to overcome limitations in the standard earthquake-location programs available at the time and to take advantage of the detailed seismic-velocity information obtained at Augustine Volcano. Hypocenters are calculated on the basis of a two-dimensional (2D) ray-tracing procedure that accounts for in plane lateral discontinuities within the seismic velocity structure. This algorithm calculates the minimum P- and S-wave travel time between theoretical grid points embedded in the velocity structure to each station in the seismic network. Station corrections that account for the differences between the model and actual velocity structure are derived from a time-term analysis of the 1975 active-source seismic experiment. Each relocated hypocenter is assigned to the grid point with the lowest rms residual between observed and calculated arrival times. Statistical techniques are used to assess the effect of random errors in P-wave-arrival determination on hypocentral location. These tests suggest that the 2D ray-tracing procedure presented here is able to resolve earthquake hypocenter depths to within 0.25 km between the volcano's summit and sea level and within 0.5 km from sea level to depths of 2 km below sea level.
Study Area
| Publication type | Report |
|---|---|
| Publication Subtype | USGS Numbered Series |
| Title | A two-step procedure for calculating earthquake hypocenters at Augustine Volcano: Chapter 7 in The 2006 Eruption of Augustine Volcano, Alaska |
| Series title | Professional Paper |
| Series number | 1769 |
| Chapter | 7 |
| DOI | 10.3133/pp17697 |
| Year Published | 2010 |
| Language | English |
| Publisher | U.S. Geological Survey |
| Contributing office(s) | Alaska Volcano Observatory |
| Description | Report: 13 p.; Appendix 1 |
| Larger Work Type | Report |
| Larger Work Title | The 2006 Eruption of Augustine Volcano, Alaska |
| First page | 129 |
| Last page | 142 |
| Country | United States |
| State | Alaska |
| Online Only (Y/N) | Y |
| Additional Online Files (Y/N) | Y |
| Google Analytic Metrics | Metrics page |