As the last century advanced through technology, the efforts of a global seismographic network (GSN) to locate earthquakes began to become a reality. The IRIS GSN is designed for obtaining seismic data in digital form that can be accessed by data users worldwide. The linking together of computers to share scientific data and to consolidate computing power is in the essence, the very purpose of the Net.

Seismonitor assumes an Internet connection. It polls, retrieves and parses near-realtime GSN data from the Incorporated Research Institutions for Seismology (IRIS) server directly at:

A Perl script retrieves output of all available recent seismic events, extracting the most recent event time and magnitude. When a new event occurs, the magnitude value is read; then passed to a set of time variables which controls the actual run mode of the earthquake simulator. If no change occurs, Seismonitor continues in its default state which controls an air driven breathing circuit.

About IRIS
The Incorporated Research Institutions for Seismology (IRIS) is a consortium of United States Universities that have research programs in seismology. The purpose of IRIS is to develop and operate the infrastructure needed for the acquisition and distribution of high quality seismic data.

The goal of the IRIS Global Seismic Network (GSN) is to deploy 128 permanent seismc recording stations uniformly over the earth's surface. The IRIS GSN has two principal seismic monitoring partners:

IRIS/ASL Network Operations Center
Albuquerque, New Mexico, USA
Operated by the United States Geological Survey. (USGS)

IRIS/IDA Network Operations Center
La Jolla, California, operated by personnel from Scripps Institution of Oceanography

About the Stations
As of 2001 the GSN was made up of over 120 stations with affiliations to IRIS USGS, IRIS IDA, GEOFON, Pacific21, NCDSN, MedNet, BGR, BFO, USNSN, BDSN and several other national and international networks. Thirteen new stations are planned for completion in 2001/2002.

The IRIS GSN stations continuously record seismic data from very broad band seismometers at 20 samples per second. It is also the goal of the GSN to record data with a dynamic range of 140db (24 bit digitisers). Nearly all of the IRIS GSN stations meet this goal.

Seismonitor Future Implementation
QDDS (Quake Data Distribution System)
This is a JAVA program which is used to distribute CUBIC formatted earthquake hypocenter (and optionally other) information between seismic network operators and to other users. The application runs continuously, periodically looking in its polldir for message files to distribute via a hub, and listening on an Internet port for delivery messages from hubs and placing these in its outputdir. Documentation can be found at:

Web References
Expanded online version of this catalogue

IRIS Seismic Monitor

About earthquakes

Are You Ready For An Earthquake? (116k PDF)

Catalogue Contents