Ulf Magnetic Observations: An Useful Tool to Investigate the Occurrence of Earthquake Precursors?

Abstract

In the last two decades many researchers investigated ULF (Ultra-Low-Frequency) magnetic data in the hope of finding pre-earthquake seismogenic signals. Several ULF stations were installed and many papers documented the observations of pre-earthquake magnetic anomalies. These claims motivate the belief that one day short-term earthquake prediction based on magnetic data may become a routine technique. Since the earthquake prediction is a very important topic of social importance, recently some researchers gave rise to a re-examination process of controversial scientific claims and they published their findings. These authors demonstrated that many presumed seismogenic signatures were normal variations driven by the geomagnetic activity. Here, some examples of presumed earthquake precursors are reported hoping to shed light on the usefulness of the ULF magnetic measurements to study the occurrence of pre-earthquake seismogenic signals.