In September at the United Nations, President Clinton and leaders of four other superpowers signed the Comprehensive Test Ban Treaty (CTBT), prohibiting the testing of nuclear devices around the globe. As of January, 140 nations had signed on. Now, enforcing the treaty falls on an international group charged with monitoring compliance. But how?

Partially with the help of Cornell University geologists, that's how. To assist in the effective monitoring of whether a nuclear bomb has been detonated anywhere in the world, geologists are compiling an interactive Geographic Information System (GIS), a database of global seismological, geologic, geophysical, remote sensing and geographic information so that the CTBT can be verified.

"The treaty calls for on-site inspection if a country suspects that another country is cheating," said Muawia Barazangi, senior scientist and faculty member in Cornell's Department of Geological Sciences and project leader. "You need a database at hand swiftly; you can't wait weeks for a report. Otherwise, the evidence may disappear."

Inspectors can see immediately whether a location is the site of frequent earthquakes or other events, such as mine blasts, that result in seismic activity. That could help them determine whether an on-site inspection is necessary, Barazangi said. The U.S. Congress still needs to ratify the treaty.

This digital database, easy to access via the World Wide Web http://atlas.geo.cornell.edu" and menu-driven so it's user friendly, will be useful to scientists even if they have no interest in the CTBT, Barazangi said. "It's a bonanza of information. You get the topography, earthquake locations, mining activity of the whole world, digitally."

He added: "Our GIS effort is a mere one step on the road to create the digital library of human knowledge."

Also online: coastlines, rivers, lakes, roads, major cities, seismic attenuation and velocities, crustal profiles and tectonic maps. Need to plot the Holocene or active volcanoes? No problem -- just click on that box and a custom map will pop up. Need to see all the faults in the Middle East, with coastlines outlined? Just click.

"I would say it is one of the most extensive applications of GIS in the earth sciences anywhere," Barazangi said.

The project, funded by the U.S. Department of Defense and the Department of Energy, is no simple task. A group of 12 researchers -- comprising the Middle East and North Africa Research Group of Cornell's Institute for the Study of the Continents (INSTOC) including undergraduate students, graduate students and postdoctoral associates -- work on some aspect of the database. A monitoring system of 300 stations around the world, which can monitor any earthquake or event on Earth, is used to monitor the test ban treaty. Any equivalent 1-kiloton explosion will be detected. Data from about half the stations are online now. When the system is complete, any seismic activity of about 3.5 or more on the Richter scale anywhere on Earth will be online within a half hour.

The Middle East and North African region tectonics was not widely known, or easily accessible, until the Cornell group began collecting, in 1990, all seismological, geophysical, topographical, geological and satellite imagery data into a digital system. The data will become part of the U.S. National Data Center as well as the International Data Center, now in Virginia but moving to Vienna next year, which is the center responsible for monitoring the CTBT under the auspices of the United Nations.

But the data are useful to scientists as well. Dogan Seber, a postdoctoral associate working on the project, showed how he could pick any earthquake location plotted on the system and pop up historical and scientific data for that event. Instantly.

"You can automatically obtain a cross-section profile of any database anywhere on Earth," Seber said. "We've compiled the data in a nicely organized fashion so we can also use it for research and for teaching. Other countries can use it for CTBT. It's very useful for earthquake hazard assessment. This puts everything at the researcher's fingertips. You can even overlay it with satellite images."

Digitized crustal profiles from Morocco to Iran and from Turkey to Yemen help in understanding the propagation of seismic waves. Was that a nuclear detonation in Iran or an earthquake? The database can help make a determination.

Added Barazangi: "This project provides a successful model for the international transfer of information and knowledge. The effort is multidisciplinary, involving seismology, geophysics, geology, remote sensing and computer science, among other fields. In addition, the tasks are multinational, requiring the cooperation of scientists from the United States, the Middle East and North Africa. And it has global significance, providing data and technology fundamental to verification of the CTBT."