Welcome to the NonLinLoc home page... |
See the NonLinLoc Updates page for a description of New Releases, Updates and Bugs. See the FAQ page for answers to Frequently Asked Questions. New: NLLGrid - Python class for reading and writing NonLinLoc grid files. By Claudio Satriano, Natalia Poiata: NLLGrid Most of the NonLinLoc software is distributed under the GNU General Public License (GNU GPL). (or look at a local copy of the GNU General Public License). Previous release: NonLinLoc Version 5.00 ( Most recent beta release ) For updates on ALomax software: |
The NonLinLoc (Non-Linear Location) package is a set of programs for velocity model construction, travel-time calculation and probabilistic, non-linear, global-search earthquake location in 3D structures, and for visualisation of 3D volume data and location results. Many of the programs operate with a 3D Grid structure which defines a specific, gridded, rectangular volume (Non-GLOBAL mode) or spherical section (GLOBAL mode). See the NLLoc program documentation for a description of the non-linear location inversion approach and algorithms. See the book chapters Probabilistic earthquake location in 3D and layered models: Introduction of a Metropolis-Gibbs method and comparison with linear locations (Lomax, et al., 2000) and Earthquake Location, Direct, Global-Search Methods (Lomax, et al., 2009) for further information on NonLinLoc and for an examination of synthetic 3D and 1D locations. See the report Comparison of NonLinLoc and linear earthquake locations in a 3D model for an examination of real 3D locations. NonLinLoc
supports regional/teleseismic location in a spherical,
longitude/latitude/depth coordinate system. This
is referred to as the "GLOBAL"
mode in this documentation. The original rectangular-Cartesian
location mode remains fully supported, and is referred to as the
"Non-GLOBAL"
mode where relevant. NOTE: Currently, the NonLinLoc package only includes software support for generating 1D, spherically-layered travel time grids for GLOBAL mode location. External software can be used to generate 3D travel time grids in spherical coordinates for GLOBAL mode. (A Fast Marching Method, finite-differences package for calculating travel times on 3D spherical-ellipsoidal grids is currently under development, contact Anthony Lomax for more information anthony@alomax.net) |
The NonLinLoc package consists of the following programs:
program |
mode |
description |
---|---|---|
Non-GLOBAL |
Non-Linear Location - Determines the location for one or more events within a 3D Grid using a systematic grid-search, a stochastic, Metropolis-Gibbs search, or a hybrid "Oct-Tree" method. (outputs misfit or probability density function (PDF) on a 3D Grid, PDF samples or "scatter cloud", description of best hypocenter, and other results). |
|
Non-GLOBAL |
Velocity model to 3D Model Grid - Given a velocity model description, creates a model grid. (outputs a 3D Grid) |
|
Non-GLOBAL |
3D Model Grid to Travel Time Grid - Given a 3D Model Grid, calculates travel times from a point within a 3D Grid to all other points within the grid. Optionally calculates ray take-off angles within the 3D Grid. (outputs a set of 3D Grids) |
|
Non-GLOBAL |
Travel Time Grid to Synthetic Observations - Given a hypocenter location and a set of travel time grids, calculated predicted travel times. (outputs a Phase file in NonLinLoc format) |
|
Non-GLOBAL |
Location Summation - Utility that combines NLLoc location results and PDF "scatter-cloud" samples from a number of events. (outputs a single set of summary location files) |
|
Non-GLOBAL |
Grid to GMT commands - Utility that creates a command script for plotting plotting sections and plan views of 3D Grid files, and misfit, PDF and location "scatter-cloud" results using the GMT plotting package. |
|
Non-GLOBAL |
Miscellaneous utility programs - Utilities for conversion between HYPOELLIPSE summary or FPFIT summary formats and NonLinLoc Hypocenter-Phase location format. |
|
In addition, the following analysis and visualisation software supports NonLinLoc event location output formats: |
||
Non-GLOBAL |
Java applet for viewing seismicity in 3D - Interactive, animated, local or Internet-based viewing in 3D of hypocenters, PDF "scatter-clouds", error-ellipses, residuals, geographic data and other information. |
A typical Non-GLOBAL mode location run involves:
|
A typical GLOBAL mode location run involves:
|
NonLinLoc Version
6.0.0 (MAR2011) NOTES:
SeismicityViewer Download the SeismicityViewer java code and class files: SeismicityViewer |
Download the NonLinLoc Sample Locations files: Sample location files Non-GLOBAL mode: Instructions to run the Sample Location tutorial for local events, to create a velocity grid, calculate travel times and locate an event, and visualise the results results. GLOBAL mode: Instructions to run the Sample Location tutorial for regional/teleseismic events, to create a travel-time grid, locate an event, and visualise the results results. |
Please mail questions, comments or suggestions to anthony@alomax.net |
The utility, quality and evolution of the NonLinLoc software package depends entirely on feedback from its users. Many thanks to many people for feedback, and to the following people for particularly extensive support, contributions, bug reports, comments and suggestions for the NonLinLoc software:
... AND MANY OTHERS! |
...to
Anthony
Lomax's science page.
...to Anthony
Lomax's software page.
...to ALomax
Scientific page.