Twenty years of geomagnetic field observations at Mario Zucchelli Station (Antarctica)

During the 1986-87 austral summer a geomagnetic observatory was installed at Terra Nova Bay. During the firstyears both geomagnetic field time variation monitoring and absolute measurements were carried out only duringsummer. Since 1991 variometer measurements are automatically performed throughout the year, while absolutemeasurements are still performed only during summer. In spite of this, interesting observations were obtainedduring the life (quite long for Antarctica) of the geomagnetic observatory. In particular, this paper brieflypresents some of the most important results: studies on secular variation, daily variation (and its dependencefrom solar cycle and seasons) and geomagnetic higher frequency variations, such as geomagnetic pulsations

Tectonomagnetic and VLF electromagnetic signals in Central Italy

Tectonomagnetic field observations from absolute magnetic field level measurements were undertaken in Central Italy in an area extending between latitude 41°N and 43°N and between longitude 13°E and 15°E. Moreover,natural electromagnetic signals from a system of two VLF search coil wide-band antennas were collected at the geomagnetic observatory of L Aquila (42º23'N, 13º19'E). The analysis of these data allowed the investigation of the electromagnetic properties of the study area at different time and spatial lengthscales. Tectonomagnetic field observations were obtained comparing data simultaneously recorded at three magnetometer stations using L'Aquila Observatory as a reference for differentiation. We report on the time evolution of magnetic and electromagnetic indicators related to local and regional seismic activity

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

A network of three absolute magnetometer stations and the geomagnetic observatory of LAquila (42°23N, 13°19E) monitors possible seismo- or tectonomagnetic effects in Central Italy, using LAquila Observatory as a reference for differentiation. A system of two VLF search coil wide-band antennas, working in two different frequency bands, at the LAquila 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

Fourteen years of geomagnetic daily variation at Mario Zucchelli Station (Antarctica)

During the 1986-87 austral summer a geomagnetic observatory was installed at the Italian Antarctic Base Mario Zucchelli Station. In the first three years continuous time variation monitoring and absolute measurements of the geomagnetic field were carried out only during summer expeditions. Starting 1991 an automatic acquisition system, operating through all the year, was put in operation. We present here some peculiarities of the daily variation as observed for fourteen years (1987-2000). The availability of a long series of data has allowed the definition of seasonal, as well as solar cycle effects, on short time variations as observed at a cusp-cap observatory. In particular, contrary to mid latitude behaviour, a clear dependence of the daily variation amplitude on the global geomagnetic K index was well defined

A multi-parametric and multi-layer study to investigate the largest 2022 Hunga Tonga–Hunga Ha’apai eruptions

On 20 December 2021, after six quiet years, the Hunga Tonga-Hunga Ha'apai volcano erupted abruptly. Then, on 15 January 2022, the largest eruption produced a plume well registered from satellites and destroyed the volcanic cone previously formed in 2015, connecting the two islands. We applied a multi-parametric and multi-layer study to investigate all the possible pre-eruption signals and effects of this volcanic activity in the lithosphere, atmosphere, and ionosphere. We focused our attention on: (a) seismological features considering the eruption in terms of an earthquake with equivalent energy released in the lithosphere; (b) atmospheric parameters, such as skin and air temperature, outgoing longwave radiation (OLR), cloud cover, relative humidity from climatological datasets; (c) varying magnetic field and electron density observed by ground magnetometers and satellites, even if the event was in the recovery phase of an intense geomagnetic storm. We found different precursors of this unique event in the lithosphere, as well as the effects due to the propagation of acoustic gravity and pressure waves and magnetic and electromagnetic coupling in the form of signals detected by ground stations and satellite data. All these parameters and their detailed investigation confirm the lithosphere-atmosphere-ionosphere coupling (LAIC) models introduced for natural hazards such as volcano eruptions and earthquakes

Twenty years of geomagnetic field observations at Mario Zucchelli Station (Antarctica)

During the 1986-87 austral summer a geomagnetic observatory was installed at Terra Nova Bay. During the firstyears both geomagnetic field time variation monitoring and absolute measurements were carried out only duringsummer. Since 1991 variometer measurements are automatically performed throughout the year, while absolutemeasurements are still performed only during summer. In spite of this, interesting observations were obtainedduring the life (quite long for Antarctica) of the geomagnetic observatory. In particular, this paper brieflypresents some of the most important results: studies on secular variation, daily variation (and its dependencefrom solar cycle and seasons) and geomagnetic higher frequency variations, such as geomagnetic pulsations

Signature of Tidal Sea Level in Geomagnetic Field Variations at Island Lampedusa (Italy) Observatory

In this work, we analyze the geomagnetic field measurements collected from 2017 to 2020 at the Italian observatories of Lampedusa and Duronia (an island and inland site, respectively) for investigating a possible signature of the tidal sea water level changes on the local magnetic variations. We obtain the following main results: (a) evidence of the geomagnetic power spectral peaks at the solar and lunar tidal main frequencies at both sites is found; (b) by using a robust fit procedure, we find that the geomagnetic field variations at Lampedusa are strongly influenced by the lunar tidal variations in the sea level, while at Duronia, the main effects on the geomagnetic field variations are associated with diurnal solar ionospheric tides; (c) a single-station induction arrows (SSIAs) investigation reveals different behaviors between Lampedusa and Duronia. Specifically, Lampedusa shows that the induction arrows in different frequency ranges point toward different directions with different amplitudes, probably related to the surrounding regions with different water depths, while Duronia shows a persistent coast effect, with the induction arrows pointing toward the Adriatic sea; and (d) a Superposed Epoch Analysis reveals, only for Lampedusa, a close relationship between SSIAs with a frequency of >2 mHz (<1.3 mHz) and the sea level variations driven by the astronomical O1 tide, indicating an amplitude intensification of ∼4×10−3 (∼5×10−3) and an azimuthal angle increment of ∼3∘ ( ∼9∘), in correspondence to a 1 cm sea level increase

Signature of Tidal Sea Level in Geomagnetic Field Variations at Island Lampedusa (Italy) Observatory

In this work, we analyze the geomagnetic field measurements collected from 2017 to 2020 at the Italian observatories of Lampedusa and Duronia (an island and inland site, respectively) for investigating a possible signature of the tidal sea water level changes on the local magnetic variations. We obtain the following main results: (a) evidence of the geomagnetic power spectral peaks at the solar and lunar tidal main frequencies at both sites is found; (b) by using a robust fit procedure, we find that the geomagnetic field variations at Lampedusa are strongly influenced by the lunar tidal variations in the sea level, while at Duronia, the main effects on the geomagnetic field variations are associated with diurnal solar ionospheric tides; (c) a single-station induction arrows (SSIAs) investigation reveals different behaviors between Lampedusa and Duronia. Specifically, Lampedusa shows that the induction arrows in different frequency ranges point toward different directions with different amplitudes, probably related to the surrounding regions with different water depths, while Duronia shows a persistent coast effect, with the induction arrows pointing toward the Adriatic sea; and (d) a Superposed Epoch Analysis reveals, only for Lampedusa, a close relationship between SSIAs with a frequency of >2 mHz (4×10−3 (∼5×10−3) and an azimuthal angle increment of ∼3∘ ( ∼9∘), in correspondence to a 1 cm sea level increase

Geomagnetic Observation Result, 2013-2014

This report describes the activities performed from November 2, 2013 to December 3, 2013. For the present work H, D and Z INTERMAGNET formatted data from the fluxgate magnetometer EDA have been used. The proton precession magnetometers used to record F total values were Overhauser type; for a description of instruments we refer to geomagnetism text books, for example Parkinson (1983) and Wienert (1970). Since the total intensity F time variations, at polar latitudes, where values of inclination is almost 90, are very close to the vertical component Z time variations, the plots of total intensity time variations are not shown. They can however be obtained from the well known equation:ingvPublished1A. Geomagnetismo e Paleomagnetismo5IT. Osservator