The INGV tectonomagnetic network

The Italian Istituto Nazionale di Geofisica e Vulcanologia (INGV) tectonomagnetic network was installed in Central Italy since the middle of 1989 to investigate possible magnetic anomalies related to earthquakes. The network is part of the INGV L'Aquila Geomagnetic Observatory and is located in an area extending approximately in latitude range [41.6°–42.8°] N and longitude range [13.0°–14.3°] E. Actually the network consists of four stations where the total magnetic field intensity data are collected using proton precession magnetometers. New stations will be added to the network starting from the end of 2007. Here we are reporting the whole data set of the network's stations for the period 2004–2006. No significant anomaly in the local geomagnetic field correlated to the seismic activity has been found. Some considerations about misleading structures present in the data sets are reported

The development of the INGV tectonomagnetic network in the frame of the MEM Project

In the middle of 1989, the INGV (Italian <i>Istituto Nazionale di Geofisica e Vulcanologia</i>) installed in Central Italy a network of magnetic stations in order to investigate possible relationship of the local magnetic field with earthquakes occurrences. Actually the network consists of four stations, where the total magnetic field intensity data are being collected using proton precession magnetometers. Here we are report on the actual state and the future developments of the network. In the frame of the MEM (Magnetic and Electric fields Monitoring) Project, new stations will be added to the network by the end of 2007. The results of the test campaigns carried out in the sites chosen to widen the network are also discussed. Moreover, the 2006 complete data set of the network is also reported. Concerning the data analysis, a new approach is also discussed that takes into account the inductive effects on the local geomagnetic field by means of the inter-station transfer functions time variations analysis

Electromagnetic field measurements in ULF-ELF-VLF [0.001 Hz─100 KHz] bands

We are reporting the technological and scientific objectives of the MEM project. The MEM project has been activated in the INGV Observatory of L'Aquila to create in Central Italy a network of observatories in order to monitoring the electromagnetic signals in the frequency band [0.001 Hz–100 kHz]. Some examples of the instrumentation developed in the frame of the project are reported. An innovative technique, based on the wide band interferometry is proposed to obtain detailed information concerning the several detected electromagnetic sources. Moreover, data from each station will be elaborated to investigate different sectors as the structure of ground electric conductibility, the electromagnetic phenomena connected with seismic activity, the separation of the electromagnetic fields originated in the Earth's interior and the electromagnetic phenomena originated in the magnetosphere, in the ionosphere and in the Earth-ionosphere cavity

Magnetic anomalies possibly linked to local low seismicity

During the last twenty years a time-synchronized network of magnetometers has operated in Central Italy along the Apennine chain to monitor the magnetic field anomalies eventually related to the tectonic activity. At present time the network consists of five stations. In the past only few anomalies in the local geomagnetic field, possibly associated to earthquakes, has been observed, not least because the network area has shown a low-moderate seismic activity with the epicentres of the few events with Ml≥5 located away from the network station. During 2007 two Ml≈4 earthquakes occurred in proximity of two stations of the network. Here we report the magnetic anomalies in the geomagnetic field that could be related with these tectonic events. To better investigate these two events a study of ULF (ultra-low-frequency) emissions has been carried out on the geomagnetic field components H, D, and Z measured in L’Aquila Observatory during the period from January 2006 to December 2008. We want to stress that this paper refers to the period before the 2009 L’Aquila seismic sequence which main shock (Ml=5.8) of 6 April heavily damaged the medieval centre of the city and surroundings. At present time the analysis of the 2009 data is in progress

The INGV tectonomagnetic network

The Italian Istituto Nazionale di Geofisica e Vulcanologia(INGV) tectonomagnetic network was installed in Central Italy since the middle of 1989 to investigate possible magnetic anomalies related to earthquakes. The network is part of the INGV L’Aquila Geomagnetic Observatory and is located in an area extending approximately in latitude range [41.6°–42.8°]N and longitude range [13.0°–14.3°] E. Actually the network consists of four stations where the total magnetic field intensity data are collected using proton precession magnetometers. New stations will be added to the network starting from the end of 2007. Here we are reporting the whole data set of the network’s stations for the period 2004– 2006. No significant anomaly in the local geomagnetic field correlated to the seismic activity has been found. Some considerations about misleading structures present in the data sets are reported

The study of the electromagnetic anomalies linked with the Earth's crustal activity in the frequency band [0.001 Hz?100 kHz]

International audienceThe technological and the scientific objectives of the MEM (Magnetic and Electric fields Monitoring) project concerning to the study of the electromagnetic signals linked with the Earth's crustal activity are reported. The MEM project has been activated in Central Italy to create a network of observatories so as to monitoring the electromagnetic signals, both natural and artificial, in the frequency band [0.001 Hz?100 kHz]. Some examples of the developed instrumentation and the know-how transfer to the industry are reported. We also report some results obtained in the first MEM station installed in the area of the INGV (Italian Istituto Nazionale di Geofisica e Vulcanologia) Observatory of L'Aquila. Using the single station magnetotelluric approach we have obtained some valuables information about the underground resistivity structure in the area of the measurement station. Concerning to the study of the magnetic signals linked with the tectonic activity we have reported an example of the long term behaviour of the magnetic induction vectors characteristics in the lower frequency band [0.001?0.5] Hz, showing their normal behaviour when no large crustal changes due to geodynamical processes are present

The study of the electromagnetic anomalies linked with the Earth's crustal activity in the frequency band [0.001Hz-100kHz]

The technological and the scientific objectives of the MEM (Magnetic and Electric fields Monitoring) project concerning to the study of the electromagnetic signals linked with the Earth’s crustal activity are reported. The MEM project has been activated in Central Italy to create a network of observatories so as to monitoring the electromagnetic signals, both natural and artificial, in the frequency band [0.001 Hz-100 kHz]. Some examples of the developed instrumentation and the know-how transfer to the industry are reported. We also report some results obtained in the first MEM station installed in the area of the INGV (Italian Istituto Nazionale di Geofisica e Vulcanologia) Observatory of L’Aquila. Using the single station magnetotelluric approach we have obtained some valuables information about the underground resistivity structure in the area of the measurement station. Concerning to the study of the magnetic signals linked with the tectonic activity we have reported an example of the long term behaviour of the magnetic induction vectors characteristics in the lower frequency band [0.001-0.5] Hz, showing their normal behaviour when no large crustal changes due to geodynamical processes are present

Electromagnetic field measurements in ULF-ELF-VLF [0.001 Hz–100KHz] bands

We are reporting the technological and scientific objectives of the MEM project. The MEM project has been activated in the INGV Observatory of L’Aquila to create in Central Italy a network of observatories in order to monitoring the electromagnetic signals in the frequency band [0.001 Hz–100 kHz]. Some examples of the instrumentation developed in the frame of the project are reported. An innovative technique, based on the wide band interferometry is proposed to obtain detailed information concerning the several detected electromagnetic sources. Moreover, data from each station will be elaborated to investigate different sectors as the structure of ground electric conductibility, the electromagnetic phenomena connected with seismic activity, the separation of the electromagnetic fields originated in the Earth’s interior and the electromagnetic phenomena originated in the magnetosphere, in the ionosphere and in the Earth-ionosphere cavity

Update on monitoring of magnetic and electromagnetic tectonic signals in Central Italy

A network of three absolute magnetometer stations and the geomagnetic observatory of L’Aquila (42°23N, 13°19E) monitors possible seismo- or tectonomagnetic effects in Central Italy, using L’Aquila Observatory as a reference for differentiation. A system of two VLF search coil wide-band antennas, working in two different frequency bands, at the L’Aquila Observatory, monitors possible electromagnetic effects related to seismic events occurring in Central Italy. Absolute magnetic field observations and VLF signals have been collected for several years. In particular the tectono-magnetic network started its operations in 1989. In this paper we report on the time variation of above mentioned data for the most recent years 2002 and 2003, also in connection with older measurements time series; we also report on seismic activity recorded in this area by the national seismic network. In the above mentioned time interval, no strong earthquake activity was recorded, and at the same time no clear evidence for magnetic or electromagnetic signals related to seismic events was found