What is GISMO?

GISMO is an open-source MATLAB toolbox for seismic data analysis. In particular, GISMO provides an object-oriented framework for the analysis of seismic waveform and event catalog data.

GISMO provides parsers for common seismic waveform (e.g. SAC, Seisan, Antelope/Datascope - Miniseed will be added soon) and catalog file formats (Seisan, Antelope/Datascope - hypoellipse and hypoinverse will be added soon), and also wraps the irisfetch.m program to fetch waveform and catalog data directly from the IRIS Data Management Center.

GISMO includes: (1) a set of low level classes that describe types of seismic data, e.g. seismic waveform data, seismic event catalogs, etc.; (2) a set of higher level classes that describe common forms of seismic data analysis, e.g. correlation of waveform objects; and (3) an ever-evolving set of contributed codes built around these core products.

GISMO is a superset of "The Waveform Suite" developed by Celso Reyes, which is still available as a standalone toolbox from the MATLAB File Exchange. GISMO also includes Mike West's correlation class.

The goal of the GISMO project is to make seismology research easier:

• GISMO knows how to get data from a variety of sources / data formats, spanning file boundaries. This is often the most time consuming part for seismologists writing their own code from scratch.
• GISMO simplifies everything by turning data from any source into a waveform or catalog object.
• Common types of time series plots are built-in to GISMO, e.g. record section plots, helicorder plots, spectrograms, depth-time sections, number of events per unit time, energy release per unit time. Also map view and cross-section of hypocentral data.
• Many common processing methods are also included, e.g. GISMO includes an extensive set of tools for correlation analysis.
• GISMO encourages community development of an integrated set of codes and accompanying documentation, eliminating the need for seismologists to "reinvent the wheel". Contributed codes are an important feature of GISMO.
• By sharing code we also enhance the repeatability of science, in conjunction with the fact that IRIS DMC makes many datasets universally available.

The name "GISMO" was originally an abbreviation for "Geophysical Institute Seismology Matlab Objects", signifying that it is an object-oriented toolbox originally created within the University of Alaska Fairbanks' Geophysical Institute's Seismology group. However, GISMO is used and contributed to by a large number of scientists outside the Geophysical Institute, so we now think of this as "Geophysical Investigations in Seismology with Matlab Objects". The other meaning of "gismo" or "gizmo" is "a useful tool; a gadget".

GISMO does not intend to compete with ObsPy, which is a superb open-source toolbox for seismology written in Python. But if you are a seismologist using MATLAB rather than Python - perhaps because you are not a Python programmer, or because you are trying to integrate with other codes written in MATLAB - you will probably find GISMO helpful.