DATA ACQUISITION OF GLOBALLY MONITORED SEISMIC DATA
From early times, human curiosity about the world has stimulated attempts to make recorded measurements of natural phenomena. Insights into the attributes and even the causes of natural phenomena hinge on quantitative scientific representations. The ground shaking that inspires apprehension or even terror is encapsulated as a wavy line traced on film or tabulated as a list of numbers in computer memory. The global surveillance of earthquakes enables "remote sensing" of seismic events in inhabited and uninhabited parts of the world to be monitored uniformly. Seismographs are sensitive to ground shaking from any source. They will record the shaking that arises from great storms in the ocean and the crashing of ocean waves on a coastline, as well as the ground vibrations from road traffic and other works of man.
Scientists of the U.S. Geological Survey (USGS) have operated seismographic stations throughout the world for more than 35 years. For the past few years, in cooperation with the Incorporated Research Institutions for Seismology (IRIS---a consortium of more than 90 universities), the USGS has begun to upgrade the system into a state-of-the-art Global Seismographic Network (GSN). The GSN is designed for obtaining high quality data in digital form that can be readily accessed by data users worldwide. Most data is accessed via computer modems. For some stations, the data are reported to orbiting satellites, and thence to the Internet where information can be viewed using the World Wide Web.
Global Seismic Network Resources
USGS Global Seismic Network Fact Sheet
USGS Albuquerque Seismological Laboratory