Israeli, Chinese, French scientists reveal hidden process behind cracks, earthquakes

JERUSALEM, Sept. 7 (Xinhua) -- Israeli, Chinese, and French scientists have uncovered a hidden process that takes place before materials suddenly break, a finding that could help explain how earthquakes begin, the Hebrew University of Jerusalem said in a statement Monday.

In their new study, published in Physical Review Letters, the researchers found that cracks do not always appear and spread suddenly. Instead, they can begin as tiny, two-dimensional damaged areas that slowly grow inside a material.

Through experiments and high-speed cameras, the team found that these small damaged areas can grow extremely slowly, at speeds ranging from microns to millimeters per second, making up at least 75 percent of the entire breaking process.

The major change occurs when the damaged area extends through the material's full thickness and forms a larger crack, causing the material to break in a fraction of a second.

The researchers said the same basic process may also occur when surfaces suddenly slide against each other, as happens during earthquakes, therefore helping scientists better understand how fractures and earthquakes begin.