The devastating earthquake that struck the Soviet Republic of Armenia this week seems bound to test much more than Russia's resilience.

The disaster also could test the world's compassion in providing relief from the damage - and the Kremlin's new-found "openness" to the scrutiny that could come with such help from the outside.Already offers of help are coming from organizations in the U.S., France, Belgium, Greece, Norway, West Germany, and Bulgaria. Internationl assistance is certainly in order in view of the magnitude of the quake, the worst in the region in 80 years and among the strongest ever in the entire Soviet Union. While exact figures on the extent of the damage are still hard to come by, several cities are said to have been virtually destroyed and the death toll could reach 100,000. Some 400,000 people are homeless.

What's more, the devastation comes at a time when the Soviet economy is known to be particularly frail.

This week's quake demonstrates how hard it still is to predict such tremors despite concerted international efforts by seismologists to develop and improve forecasting techniques.

Russia's disaster also should remind Americans of their own vulnerability to earthquakes and of their comparative good fortune - so far.

Some 70 million Americans live in areas where there is a significant risk to their lives and property from earthquakes, according to the National Academy of Sciences. Another 115 million are exposed to a less significant, but not negligible, seismic risk. Only 8 percent of Americans can safely ignore the earthquake hazard.

Yet, in more than 200 years, only 1,600 Americans have died in earthquakes. By contrast, some 74 million people around the world are known to have died throughout history as a result of earthquakes or the floods, fires, and landslides the tremors triggered.

The threat seems bound to become worse as population growth concentrates more people in bigger cities and more construction takes place in geographically unstable areas.

The immediate challenge, of course, is to provide relief as swiftly and effectively as possible to the people of Armenia. As devastating as this week's quake was, it is no more than a national disaster so far. It could have become an international disaster if the rest of the world were slower to help than it has been so far.