Options
Istituto di Mineralogia, Università di Ferrara, Italy
7 results
Now showing 1 - 7 of 7
- PublicationRestrictedGeomagnetic survey of Italy. Repeat station network and magnetic maps: a short report(1985)
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ;; ; ;; ; ; ; ; ; ;; ; ;; ; Starting in 1977, two geomagnetic project were undertaken in the frame of the <>of the Consiglio Nazionale delle Ricerche(Project<>of the National Research Council);1)a new national network of repeat stations for total field F, horizontal component H, vertical component Z, declination D.2)a 2nd order network of stations for F,Z,H to produce geomagnetic maps of Italy. The two projects were carried out by a <> made up of Operating Units from Institutions to which the authors belong. The field work ended in 1981. The Istituto Nazionale di Geofisica coordinated the operations for both projects. This paper is intended to give a short report to the international scientific community on this work which has so far only appeared in the Italian literature.181 9 - PublicationOpen AccessA MT 2D modelling of the Apenninic margin and Bradanic trough after identification of an artificial e.m. wide-band source on the natural MT data(1997-10)
; ; ;Iliceto, V.; Dipartimento di Geologia, Paleontologia e Geofisica, Università di Padova, Italy ;Santarato, G.; Istituto di Mineralogia, Università di Ferrara, Italy; In the frame of Italian research project «CROP», a magnetotelluric (MT) survey was carried out in Southern Italy, above the Apulian platform, with the aim to investigate its transition beneath the Apennine chain. The MT stations were divided into two areas, the first around Lavello town, the second south of Mount Vulture inactive volcano. The standard processing of MT raw data, collected with the single-site scheme, gave fairly non-plane wave response as concerns data of Lavello area, while the volcano's area data were compatible with a natural plane-wave e.m. field response. The Lavello area results were shown to be heavily affected by a near field effect of a strong wide-band electromagnetic source located several kilometers NE of Lavello. After the identification of this effect and an attempt to interpret these data, a 2D interpretation of the whole survey was then possible and the main result can be summarized as follows: a) the «electrical» boundary of the Bradanic trough should be displaced about 4 km toward SW; b) in the area south of Melfi town, the carbonatic platform should lie at a depth of about 8 km.173 137 - PublicationOpen AccessPreliminary design of a RESPER probe prototype, configured in a multi dipole-dipole array.(2011-05-20)
; ; ; ; ; ; ;Settimi, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia ;Tutone, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia ;Baskaradas, J. A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia ;Bianchi, C.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia ;Zirizzotti, A. E.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia ;Santarato, G.; UNIVERSITÀ DEGLI STUDI DI FERRARA, Dipartimento di Scienze della Terra; ; ; ; ; The RESPER probe has been assembled, except the metallic points that must ensure the contact, by insulating materials and more specifically in Tufnol, as regards the support plates, and Teflon, as regards the standoffs. A series of holes has been drilled on the surface of support plates in order to allow approaching each other of the two central electrodes to external ones, from a minimum of 4.29 cm to a maximum of 10 cm, as shown in the table of configurations. The dipole-dipole array defined by the integer parameter n = 6 could not be implemented, as the positioning of suitable “spring” poles requires 6 mm holes and an adequate space could not be available to carry out the drilling. The presence of these “spring” poles allows reaching a right prominence of the tip from the base and, at the same time, a certain amount of pressure which ensures the proper adherence to the artifact that must be tested. There is a brass screw within each pole, which edge has been turned to the measurement of 1.4 mm. Four metal spacers are replaced of time in time depending on the configuration that is to be adopted. The achievement of height l(n) from the plates is ensured by the presence of metallic spacers, which dimensions are reported. To complete the description, a copper cable, 1 m long and with a 4.0 mm2 section area, has been welded to the head of each electrode. The two transmitting or reading cables are kept at a fixed distance L(n) between them by means of Teflon rods in which has been applied the same series of holes existing on the Tufnol plates.584 134 - PublicationOpen AccessGeomagnetic survey of Italy at 1979.0 Repeat station network and magnetic maps(1994)
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ;A national network of 106 repeat stations for total field F, horizontal component H, vertical component Z and declination D has been undertaken in the frame of the 'Progetto Finalizzato Geodinamica' of the Consiglio Nazionale delle Ricerche. From the observed magnetic elements the repeat station values were referred to 1979.0 and five normal fields in the form of a 2nd order polynomial in latitude and longitude were computed: GDN for the whole Italian area, GDN-N for the northern Italy, GDN_C for central Italy, GDN-S for the southern Italy and GDN-Sn for Sardinia. From comparisons made on F between GDN and two planetary reference fields it has concluded that for total field the polynomial form can be well considered as representative of the main field in the Italian area. A 2nd order network of 2500 stations for F, Z, H, has been undertaken to produce geomagnetic maps of Italy. An anomaly map for F referred to the GDN normal field has been drawn. The main features of anomalies configuration are described.168 63 - PublicationRestrictedNon-inductive component of electromagnetic signals associated with L’Aquila earthquake sequences estimated by means of inter-station impulse response functions(2010-05-02)
; ; ; ; ; ; ;Di Lorenzo, C.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia ;Palangio, P.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia ;Santarato, G.; Università degli Studi di Ferrara, Italy ;Meloni, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia ;Villante, U.; Università degli studi di L’Aquila, Italy ;Santarelli, L.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; ; ; ; ; On 6 April 2009 at 01:32:39 UT a strong earthquake occurred west of L'Aquila at the very shallow depth of 9 km. The main shock local magnitude was Ml = 5.8 (Mw = 6.3). Several powerful aftershocks occurred the following days. The epicentre of the main shock occurred 6 km away from the Geomagnetic Observatory of L'Aquila, on a fault 15 km long having a NW-SE strike, about 140°, and a SW dip of about 42°. For this reason L'Aquila seismic events offered very favourable conditions to detect possible electromagnetic emissions related to the earthquake. Data used in this work come from the permanent geomagnetic Observatories of L’Aquila and Duronia. Here the results concerning the analysis of the residual magnetic field estimated by means of the inter-station impulse response functions in the frequency band from 0.3 Hz to 3 Hz are shown.196 31 - PublicationOpen AccessAn experiment of spectral induced polarization(1994-11)
; ; ; ; ; ; ;Balia, B.; Dipartimento di Ingegneria del Territorio, Università di Cagliari, Italy ;Deidda, G. P.; Dipartimento di Ingegneria del Territorio, Università di Cagliari, Italy ;Godio, A.; Dipartimento di Georisorse e Territorio, Politecnico di Torino, Italy ;Ranieri, G.; Dipartimento di Georisorse e Territorio, Politecnico di Torino, Italy ;Sambuelli, L.; Dipartimento di Georisorse e Territorio, Politecnico di Torino, Italy ;Santarato, G.; Istituto di Mineralogia, Università di Ferrara, Italy; ; ; ; ; A Spectral Induced Polarization (SIP) survey was carried out in a mining test site in Sardinia (Italy). Measurements were developed along a profile by using an axial dipole-dipole array with 10 AB positions and 6 MN positions for cach AB. The amplitude and phase spectra of the apparent resistivity were acquired in the 0.25-4096 Hz frequeney range. The results obtained through the processing and inversion step seem to confirm that, with respect to the classical TD/FD Induced Polarization, SIP allows better discrimination of some important characteristics of mineral deposits such as mineral content and grain size.181 303 - PublicationOpen AccessNon-inductive components of electromagnetic signals associated with L’Aquila earthquake sequences estimated by means of inter-station impulse response functions(2011-04-06)
; ; ; ; ; ; ;Di Lorenzo, C.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia ;Palangio, P.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia ;Santarato, G.; Universit`a degli Studi di Ferrara, Italy ;Meloni, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia ;Villante, U.; Universit`a degli studi di L’Aquila, Italy ;Santarelli, L.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; ; ; ; ; On 6 April 2009 at 01:32:39 UT a strong earthquake occurred west of L’Aquila at the very shallow depth of 9 km. The main shock local magnitude was Ml = 5.8 (Mw=6.3). Several powerful aftershocks occurred the following days. The epicentre of the main shock occurred 6 km away from the Geomagnetic Observatory of L’Aquila, on a fault 15 km long having a NW-SE strike, about 140 , and a SW dip of about 42 . For this reason, L’Aquila seismic events offered very favourable conditions to detect possible electromagnetic emissions related to the earthquake. The data used in this work come from the permanent geomagnetic Observatories of L’Aquila and Duronia. Here the results concerning the analysis of the residual magnetic field estimated by means of the inter-station impulse response functions in the frequency band from 0.3 Hz to 3 Hz are shown.547 131