A new magnetotelluric monitoring network operating in Agri Valley (Southern Italy): study of stability of apparent resistivity estimates

The multiple segmenting method (MSM) has been applied to investigate the scaling behaviour in the Earth's apparent resistivity time series, measured in a seismic area of southern Italy. The study of apparent resistivity represents one of the most important scientific challenges in the studies devoted to the geophysical monitoring. Our results show that apparent resistivity is characterized by a persistent scaling behaviour at all the periods considered, with the scaling exponent tending approximately to 0.5.

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Vertical dipoles to detect self potential signals in a seismic area of southern Italy: Tito station

Natural Hazards and Earth System Science ◽

10.5194/nhess-5-667-2005 ◽

2005 ◽

Vol 5 (5) ◽

pp. 667-671

Author(s):

G. Colangelo ◽

V. Lapenna ◽

L. Telesca

Keyword(s):

Southern Italy ◽

Vertical Component ◽

Monitoring Network ◽

Large Data ◽

National Council ◽

Geophysical Time Series ◽

Common Electrode ◽

Cultural Noise ◽

Seismic Area ◽

Self Potential

Abstract. Since 2000 the Institute of Methodologies for the Environmental Analysis (National Council of Research, Tito, Italy) installed a geophysical monitoring network able to detect geoelectric, geochemic and seismometric parameters in seismic areas of southern Italy. During this period a very large data-base of geophysical time series has been organized and it is actually available to assess robust statistical methodologies to identify geophysical anomalous patterns linked with local seismicity. To better understand the influence of rain and cultural noise on geoelectrical signals (Self Potential), during May 2004 we drilled in Tito station a 20 m-depth hole to measure the SP vertical component. The array is characterized by five Pb-PbCl2 electrodes put at different depths. The common electrode is fixed at 20 m. In this work we present some electrical anomalies probably correlated with local seismic activity on vertical dipoles recorded in Tito station.

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Stability analysis of apparent resistivity measurement in the seismically active area of Val d'Agri (southern Italy)

Natural Hazards and Earth System Science ◽

10.5194/nhess-4-775-2004 ◽

2004 ◽

Vol 4 (5/6) ◽

pp. 775-781 ◽

Cited By ~ 2

Author(s):

M. Balasco ◽

V. Lapenna ◽

A. Siniscalchi ◽

L. Telesca

Keyword(s):

Apparent Resistivity ◽

Southern Italy ◽

Resistivity Measurement ◽

Tectonic Activity ◽

Impedance Tensor ◽

Night Time ◽

Electrokinetic Effect ◽

The Stability ◽

Generation Mechanisms ◽

Depth Sounding

Abstract. A magnetotelluric monitoring station has been installed in the Val d'Agri area (southern Italy), to investigate the physics underlying the generation mechanisms of the electrokinetic effect, due to rapid pore pressure changes and fluid flows near the focal area of incoming earthquakes. It is well known that the magnetotelluric method reveals variations in electrical resistivity within the Earth at large depths, reaching within appropriate frequency bands the Earth's mantle. Depth sounding is performed by measuring the ratio between the mutually perpendicular horizontal electric and magnetic fields at the earth's surface, furnishing the apparent resistivity, which describes the electrical properties of subsoil as function of depth. The selected site of Val d'Agri has been struck by strong seismic events in past and recent years, this suggesting the investigation of possible changes in apparent resistivity correlated with the local tectonic activity. We analyzed the stability of the measurement of apparent resistivity and phase of the impedance tensor Z(ω) during time. Our findings suggest that the measure of apparent resistivity during night-time is more stable. Therefore, we identified the characteristic apparent resistivity curve of the subsoil of the Val d'Agri site, which could be considered as a reference.

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The seismic monitoring network of Mt. Vesuvius

Annals of Geophysics ◽

10.4401/ag-6456 ◽

2013 ◽

Vol 56 (4) ◽

Author(s):

Massimo Orazi ◽

Luca D’Auria ◽

Anna Tramelli ◽

Ciro Buonocunto ◽

Marco Capello ◽

...

Keyword(s):

Data Transmission ◽

Southern Italy ◽

Monitoring Network ◽

Seismic Monitoring ◽

Volcanic Edifice ◽

Seismic Events ◽

Civil Protection ◽

Current Configuration ◽

Moderate Seismicity ◽

Italian National Institute

<p>Mt. Vesuvius (southern Italy) is one of the most hazardous volcanoes in the world. Its activity is currently characterized by moderate seismicity, with hypocenters located beneath the crater zone with depth rarely exceeding 5 km and magnitudes generally less than 3. The current configuration of the seismic monitoring network of Mt. Vesuvius consists of 18 seismic stations and 7 infrasound microphones. During the period 2006-2010 a seismic array with 48 channels was also operative. The station distribution provides appropriate coverage of the area around the volcanic edifice. The current development of the network and its geometry, under conditions of low seismic noise, allows locating seismic events with M<1. Remote instruments continuously transmit data to the main acquisition center in Naples. Data transmission is realized using different technological solutions based on UHF, Wi-Fi radio links, and TCP/IP client-server applications. Data are collected in the monitoring center of the Osservatorio Vesuviano (Italian National Institute of Geophysics and Volcanology, Naples section), which is equipped with systems for displaying and analyzing signals, using both real-time automatic and manual procedures. 24-hour surveillance allows to immediately communicate any significant anomaly to the Civil Protection authorities.</p>

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