Ed Yeates ReportingGeologists have now dissected our infamous Wasatch Fault with the longest and deepest trench yet. Called a Megatrench, the huge slice goes deeper than any previous one and could give researchers a new sense of earthquake risks in the Provo area.
Three hundred feet long and 30 feet down, geologists here really wanted to carve out a deep diary that documents five to six earthquakes a long way back.
Gary Christenson, Utah Geological Survey: "To do that, you have to dig it deeper and longer."
Out of all the segments of the Wasatch Fault which extend from Brigham City on the North to Nephi on the south, the 50 mile long Provo segment seems to produce the strongest earthquakes.
Gary Christenson, Utah Geological Survey: "The displacement is larger on the Provo segment and it's a longer segment than any of the others. When you take larger, what magnitude? We're talking on the order of 10 to 15 feet at once."
In Magnitude that's greater than seven. Geologists and seismologists are really looking for probabilities here - when we might expect the next BIG one and which segment along the Wasatch Fault is most likely to break loose next.
Based on data so far from the trenches, the Wasatch Fault, though extremely quiet for a long time, has a rhythm. Earthquakes occur fairly frequently and at regular intervals.