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FOCI is the stand-alone Windows GUI application for performing the seismic moment tensor inversion and source parameters assessment using waveform data. The application is optimized for local-to-regional applications and seismic networks.

The seismic moment tensor inversion module uses first P-wave motion data to invert for the unconstrained full moment tensor. In addition, the constrained trace-null and double-couple moment tensors are calculated as well. The calculated moment tensors are then decomposed into isotropic (ISO) and deviatoric parts (CLVD/DC) using classical procedure. The tensor is also used to derive the orientation of nodal planes, tension and pressure axes, total seismic moment and moment magnitude. The results of moment tensor inversion can be display in a form of beach balls using different projection schemes.

The associated spectral analysis module allows to investigate basic static and dynamic source characteristics including seismic moment, source radius, static stress drop, average displacement over the fault surface, radiated energy and apparent stress. The input P- or S-wave waveforms are first pre-processed according to User wishes and in the following the classical spectral analysis is performed using so-called Snoke’s integrals.

The output data can be exported to ASCII and XML files. The graphical representation of the moment tensor inversion can be exported to PNG, PDF, PS and SVG. The application is capable to directly read and process various file formats holding waveform information from acquisition systems typically used to monitor induced seismicity in Poland (ARAMIS, ARAMIS ME, ELOGOR-C, etc.). It also handles native FSF format, for which C++ and MATLAB FSF read/write routines are available to the end-user.

The application was designed for Windows 7/8.x/10 systems.

Download foci sofware package

The application is available in two versions (free and full) and two languages (english and polish). The free version allows for full waveform processing, however only native FSF format can be used (the installed contains sample FSF files that allows to get acquainted with the application). The full version allows to read various data program, depending on the active license that is stored withing a USB license key. If the key is not available, the full version behaves identically to free version.

To download FOCI software package, please use selected link below:

Full Version (Microsoft Windows, polish language)

File size: 21.1 MB | File version: 3.9.3-x86-pl | Downloaded: 62

Full Version (Microsoft Windows, english language)

File size: 11.5 MB | File version: 3.9.3-x86-en | Downloaded: 106

Freeware version (Microsoft Windows, polish language)

File size: 21.1 MB | File version: 3.9.3-x86free-pl | Downloaded: 62

Freeware version (Microsoft Windows, english language)

File size: 11.3 MB | File version: 3.9.3-x86free-en | Downloaded: 75

Additional materials

Samples of application

Additional documents or papers that used FOCI software package.

Hassoup, A., and G. Kwiatek (2005). Focal mechanism of earthquakes from the June 1987 swarm in Aswan, Egypt, calculated by the moment tensor inversion, Acta Geophys. Pol. 53, no. 3, 275–291.

Kwiatek, G., and N. Melis (2007). Routine analysis of focal mechanism – moment tensor solutions of moderate, small magnitude events in Greece: An example of the Gulf of Corinth region, in Geophys. Res. Abstr., vol. 9, pp. EGU2007-A-01706, European Geosciences Union.

Orlecka-Sikora, B., Papadimitriou, E.E., and G. Kwiatek (2009). Study of the interaction among mining induced seismic events in the Legnica-Glogów Copper District, Poland. Acta Geophys., 57(2): 413–434, DOI: 10.2478/s11600-008-0085-z.


These tutorials are available on my YouTube channel. They show selected functionalities of FOCI software package. Please note that these tutorials are presented in polish (however, they still may be useful).

NOTE: After running the tutorial, please check if you use the best quality (720 px HD) video.

Focal mechanisms

General information on how to calculate focal mechanisms.

FOCI - Mechanizmy - Cz. 1. Informacje ogólne

FOCI - Mechanizmy - Cz. 1. Informacje ogólne

Semi-automatic picking of seismograms

This video clip shows how to use semi-manual autopicking feature.

FOCI - Automatyczne pikowanie pierwszego wstąpienia

Station influence test

This video clip shows how the “station test” works.

FOCI - Test wpływu stacji

Spectral analysis – introduction

Introduction to spectral analysis module.

FOCI - Analiza spektralna - Cz. 1. Wprowadzenie


Paweł Wiejacz, Bogusław Domański, Sławomir Jerzy Gibowicz, Marek Burdzy, Ryszard Makowski, Marian Król, Wojciech Dębski, Eugeniusz Koziarz, Ilona Kwiatkowska, Marcin Pussak, Anita Zych-Kotwicka, Artur Kotwicki, Łukasz Rudziński, Nikos Melis, Beata Orlecka-Sikora, Bożena Hersztowska, Katrin Plenkers, Grzegorz Lizurek, Grażyna Maziarz-Wiorek, Bożena Hersztowska, Katrin Plenkers, Oliver Germer, Patricia Martinez-Garzon, Wojciech Białoń.