Earth ChangesScientists on red alert as ‘sleeping giant’ fault threatens to snap without warning beneath 300,000 Americans Posted on July 28, 2025 by Administrator A major California fault once thought to be stable is quietly shifting beneath neighborhoods, schools, and it could lead to a powerful quake with no warning. A new US geological (USGS) survey showed that Concord Fault, a geologic fault in the San Francisco Bay Area, is active and moving due to ongoing tectonic motion between the Pacific and North American plates. A section of the fault, known as the Madigan Avenue strand, stretches 12.4 miles through Walnut Creek and Concord, from North Gate Road near Mount Diablo to Suisun Bay — areas home to more than 300,000 people.
