When People Push Water Deep Under Ground, It Can Cause Repeating Ground Shakes

We look for ground shakes that repeat many times using a fast computer. We can do this when people put out a box that senses ground waves and stores all of them in computer memory. When a ground shake happens, we take the wave form from the ground shake, and use the fast computer to look for any matching wave forms in all of the ground waves stored in memory. Repeating ground shakes can happen when people push water deep down into the ground, which makes it easier for rocks to slip past each other. Sometimes people really push water down deep to break tight rocks and get more stuff stored inside that we use for power. The left over water from breaking rocks is not clean so it often gets pushed down even deeper, far away from the water people drink. In 99 out of 100 cases, pushing the water deep down under ground does not cause ground shakes we can see, even with a computer. Even fewer cases can be felt by people. In the cases where the water causes ground shakes, very small repeating ground shakes often happen early on. We can use a fast computer to find these repeating ground shakes to help us know if larger ground shakes might happen.