It is almost impossible to predict earthquakes. But in some cases it is possible, for example, if they are caused by reservoirs. This has been demonstrated, at least, in a region of India, around the Koyna reservoir. In May microcarías were produced and data were collected and a comprehensive study was announced (seismologists have forty years of experience) that the reservoir was going to produce an earthquake of 4th magnitude before fifteen days. And so it happened.