U. S. Geological Survey Open-File Report 99-23

U.S. Department of the Interior
U.S. Geological Survey

A Computer Program for Determining
Local Earthquake Hypocentral Parameters,
Magnitude, and First-Motion Pattern
(Y2K Compliant Version)

1999 Version 1.0

By John C. Lahr
Denver Federal Center
Box 25946, Mail Stop 966
Denver, CO 80225
(303) 273-8596

U. S. Geological Survey Open-File Report 99-23, On-Line Edition

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Table of Contents

Title Page

Chapter 1 -- Introduction to HYPOELLIPSE

Chapter 2 -- HYPOELLIPSE Users Guide

Chapter 3 -- Error Estimates

Chapter 4 -- Magnitude Determinations

Chapter 5 -- Determination of Vp/Vs Ratio

Chapter 6 -- Generating Travel-Time Tables

Chapter 7 -- Use of Cylindrical Delay Regions

Chapter 8 -- Summary of Important Formats

Chapter 9 -- Acknowledgements

Chapter 10 -- References