The Master Thesis work has its main focus on Optical Fiber Sensing, applied to the detection of dangerous events in several types of geology monitoring, such as for debris in a mountain scenery. In particular, the monitoring system that has been built is based on the detection of vibrational events through the continuous check of the polarization state of light conveyed inside the fibers. The intensity of the stresses that happen on the fiber is strictly related to the speed with which the polarization state changes with time. The sensor proposed in this Thesis bases its working principle on this concept, in particular on the computation of the angular speed at which the Stokes vector, which conventionally represents the polarization state over the Poincaré sphere, changes along time.