Lili Cafarella
Istituto Nazionale di Geofisica e Vulcanologia, Roma 2, Department Member
Research Interests:
Research Interests:
Research Interests:
Research Interests:
We conducted a statistical analysis of the micropulsation activity detected during 1998 at the Antarctic Italian geomagnetic observatory at Terra Nova Bay (corrected ge- omagnetic latitude: -80 degrees). In particular, the availability of... more
We conducted a statistical analysis of the micropulsation activity detected during 1998 at the Antarctic Italian geomagnetic observatory at Terra Nova Bay (corrected ge- omagnetic latitude: -80 degrees). In particular, the availability of high resolution (1 Hz) data for an entire year allowed us to extend also to the local winter, for the first time, the analysis of the daily
Research Interests:
In this work we present a statistical analysis of geomagnetic field fluctuations in the Pc5 frequency band at Terra Nova Bay (Antarctica) and Cambridge Bay (Canada). The location of the two stations is particularly interesting in that... more
In this work we present a statistical analysis of geomagnetic field fluctuations in the Pc5 frequency band at Terra Nova Bay (Antarctica) and Cambridge Bay (Canada). The location of the two stations is particularly interesting in that they have exactly the same magnetic local time (MLT=UT-8hr) and almost opposite corrected geomagnetic latitude (-80.0^o and 77.4^o, respectively). The analysis is extended
Research Interests:
Propagation of low frequency geomagnetic field fluctuations in Antarctica: comparison between two polar cap stations
A statistical analysis of the polarization pattern of low-frequency geomagnetic field fluctuations (0.7-7.4 mHz) covering the entire 24-h interval was performed at the Antarctic station Terra Nova Bay (80.0°S geomagnetic latitude)... more
A statistical analysis of the polarization pattern of low-frequency geomagnetic field fluctuations (0.7-7.4 mHz) covering the entire 24-h interval was performed at the Antarctic station Terra Nova Bay (80.0°S geomagnetic latitude) throughout 1997 and 1998. The results show that the polarization pattern exhibits a frequency dependence, as can be expected from the frequency dependence of the latitude where the coupling between the magnetospheric compressional mode and the field line resonance takes place. The polarization analysis of single pulsation events shows that wave packets with different polarization sense, depending on frequency, can be simultaneously observed.
A geomagnetic observatory is a permanent facility where magnetic declination and inclination are recorded in conjunction with the temporal evolution of the magnetic field components. Polar regions are scarcely covered by observational... more
A geomagnetic observatory is a permanent facility where magnetic declination and inclination are recorded in conjunction with the temporal evolution of the magnetic field components. Polar regions are scarcely covered by observational points then the contributions from observatories located there are particularly relevant. The geomagnetic observatory at Concordia station, Dome C - Antarctica is located in the inner part of the continent, its position is favorable for two key reasons, i) data are unaltered by the "coastal effect" and ii) crustal effect is negligible due to the thickness, almost 3 km, of ice coverage. Nevertheless, these latter conditions imply an unconsidered aspect which characterizes the entire station and every structure laying on the ice surface: the dome on which Concordia station resides is sliding horizontally and moving vertically with a velocity of few millimeter to centimeters per year as indicated by independent geodetic observations. This slow a...
Research Interests:
A b s t r a c t The study of geomagnetic field variations in Antarctica is important in that local field lines are close to extreme magnetospheric regions, such as the polar cusp, where several generation mechanisms for ULF waves are... more
A b s t r a c t The study of geomagnetic field variations in Antarctica is important in that local field lines are close to extreme magnetospheric regions, such as the polar cusp, where several generation mechanisms for ULF waves are active. Since the eighties, the Italian scientific community developed a research activity in Antarctica at Mario Zucchelli Station (TNB, CGM latitude 80°S), where magnetic facilities are continuously operating. In this review we present the experimental results obtained by a number of investigations conducted in the last years on geomagnetic pulsations in the Pc3-Pc5 frequency range. We also show compared analyses with measurements from other Antarctic and low lati-tude stations, and, in particular, a statistical analysis of propagation characteris-tics of low frequency geomagnetic field fluctuations between the two Antarctic stations, TNB and Scott Base.
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... more
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.
Research Interests:
ABSTRACT Geophysical surveys have played a fundamental role in glaciology, climatology, and geology studies conducted at and around the site of the EPICA Dome C Ice Core (Antarctica). Analysis of radio-echo sounding (RES) data collected... more
ABSTRACT Geophysical surveys have played a fundamental role in glaciology, climatology, and geology studies conducted at and around the site of the EPICA Dome C Ice Core (Antarctica). Analysis of radio-echo sounding (RES) data collected during the 2009 and 2011 Italian Antarctic Expeditions, in the immediate vicinity (2 km) of the Core site, reveals the presence of small-scale bedrock structures. Data acquired during the 2011 campaign, which applied the latest updates of our instrument, show double echoes from the ice bottom separated by very small time intervals. These reflections are distributed close to the topographic dome and do not always correspond to particular features of the bedrock structure, but instead may correspond to small-scale subglacial water storage. The unprecedented spatial resolution of the basal environment for Dome C from these recent surveys allows us to identify this and other features that have been missed by previous larger scale RES surveys of this area.
Research Interests:
The opening ,of a ,new ,magnetic ,observatory is one ,of the ,activities aimed ,at by ,the creation of a scientific base at DomeC, Antarctica (lat. 75° 06’S, long. 123° 21’E, elev. 3200m). There are many reasons supporting this objective:... more
The opening ,of a ,new ,magnetic ,observatory is one ,of the ,activities aimed ,at by ,the creation of a scientific base at DomeC, Antarctica (lat. 75° 06’S, long. 123° 21’E, elev. 3200m). There are many reasons supporting this objective: all Antarctic magnetic observatories providing absolute values are located along the shore and are therefore subject to coast effects and
Concordia is a scientific station located in the inner part of Antarctica (latitude 75° 06' S, longitude 123° 23' E, at about 3,200 m above sea level), about 950 km away from the coast. Near by the station a permanent Base is... more
Concordia is a scientific station located in the inner part of Antarctica (latitude 75° 06' S, longitude 123° 23' E, at about 3,200 m above sea level), about 950 km away from the coast. Near by the station a permanent Base is under construction and is expected to open in the year 2004. All this is the result of a
Research Interests:
The detection of illegal buried waste by means of geophysical techniques has recently become a major effort in shallow geophysical investigations. In particular, detection and location of underground metallic storage tanks can be... more
The detection of illegal buried waste by means of geophysical techniques has recently become a major effort in shallow geophysical investigations. In particular, detection and location of underground metallic storage tanks can be accomplished using different instruments and techniques. In this paper we describe the results of an investigation carried out in a tuff quarry in Riano Flaminio (north Rome,
Research Interests:
On January 10 - 11, 1997 a wide magnetic cloud crossed the Earth's orbit triggering intense geomagnetic activity. The authors present the preliminary results of the analysis of the low frequency pulsation activity observed... more
On January 10 - 11, 1997 a wide magnetic cloud crossed the Earth's orbit triggering intense geomagnetic activity. The authors present the preliminary results of the analysis of the low frequency pulsation activity observed simultaneously at very high latitudes (Terra Nova Bay, Antarctica) and at low latitudes (L'Aquila, Italy) in correspondence of different changes in the external solar wind conditions.
Research Interests:
Research Interests:
Some of the most interesting features of the geomagnetic field and its time variations are displayed in polar areas. Observatory monthly means usually provide an excellent opportunity to study the temporal changes of the magnetic field at... more
Some of the most interesting features of the geomagnetic field and its time variations are displayed in polar areas. Observatory monthly means usually provide an excellent opportunity to study the temporal changes of the magnetic field at a given location. Unfortunately, on the Antarctic continent the distribution of the permanent ground- based observatories does not permit a uniform coverage of
Research Interests:
ABSTRACT Radio-echo sounding (RES) is a radar technique widely employed in Antarctica and Greenland to define bedrock topography but, over the last decade, it has also played an important role in subglacial lake exploration and... more
ABSTRACT Radio-echo sounding (RES) is a radar technique widely employed in Antarctica and Greenland to define bedrock topography but, over the last decade, it has also played an important role in subglacial lake exploration and hydrogeological studies at the bedrock/ice interface. In recent studies, bedrock characterization has been improved through analysis of radar power echoes to evaluate the electromagnetic (EM) properties of the interface and allow the distinction between wet and dry interfaces. The RES received signal power depends on ice absorption and bedrock reflectivity, which is closely linked to the specific physical condition of the bedrock. In this paper, an evaluation of EM ice absorption was conducted starting from RES measurements collected over subglacial lakes in Antarctica. The idea was to calculate ice absorption starting from the radar equation in the case of subglacial lakes, where the EM reflectivity value is considered a known constant. These values were compared with those obtained from analysis of ice-core dielectric profiles from EPICA ice-core drilling data. Our analysis reveals that the ice absorption rate calculated from RES measurements has an average value of 7.2 dBkm–1, and it appears constant, independent of the subglacial lake depth in different zones of the Dome C area.
Research Interests:
Research Interests:
Research Interests:
Research Interests: Geophysics and Annals
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Performing good quality magnetic observations is not an easy task; making them in the extreme marine environment is even more challenging. The European funded GEOSTAR project succeeded in reaching this difficult goal. After the shallow... more
Performing good quality magnetic observations is not an easy task; making them in the extreme marine environment
is even more challenging. The European funded GEOSTAR project succeeded in reaching this difficult
goal. After the shallow seawater test experiment performed in the Adriatic Sea in 1998, the main aims of the
GEOSTAR project were achieved two years later during the six-month deep seafloor mission in the Tyrrhenian
Sea at around 2 km depth. Details and results of the shallow seawater mission in the Adriatic Sea were published
in previous articles. This paper is concerned with the deep seafloor mission in the Tyrrhenian Sea close to Ustica
Island and presents some results related to the geomagnetic recordings.
is even more challenging. The European funded GEOSTAR project succeeded in reaching this difficult
goal. After the shallow seawater test experiment performed in the Adriatic Sea in 1998, the main aims of the
GEOSTAR project were achieved two years later during the six-month deep seafloor mission in the Tyrrhenian
Sea at around 2 km depth. Details and results of the shallow seawater mission in the Adriatic Sea were published
in previous articles. This paper is concerned with the deep seafloor mission in the Tyrrhenian Sea close to Ustica
Island and presents some results related to the geomagnetic recordings.