http://hdl.handle.net/2122/230 Tue, 18 Jun 2013 21:58:37 GMT 2013-06-18T21:58:37Z http://hdl.handle.net/2122/7176 Title: A Holocene paleosecular variation record from the northwestern Barents Sea continental margin Authors: Sagnotti, L.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Macrì, P.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Lucchi, R.; Istituto Nazionale di Oceanografia e Geofisica Sperimentale, Borgo Grotta Gigante 42/c, Sgonico, Trieste I‐34010, Italy; Rebesco, M.; Istituto Nazionale di Oceanografia e Geofisica Sperimentale, Borgo Grotta Gigante 42/c, Sgonico, Trieste I‐34010, Italy; Camerlenghi, A.; Istitució Catalana de Recerca i Estudis Avançats, E‐08028 Barcelona, Spain Abstract: A high‐resolution paleomagnetic and rock magnetic study has been carried out on sediment cores collected in glaciomarine silty‐clay sequences from the continental shelf and slope of the southern Storfjorden trough‐mouth fan, on the northwestern Barents Sea continental margin. The Storfjorden sedimentary system was investigated during the SVAIS and EGLACOM cruises, when 10 gravity cores, with a variable length from 1.03 m to 6.41 m, were retrieved. Accelerator mass spectrometry (AMS) 14C analyses on 24 samples indicate that the cores span a time interval that includes the Holocene, the last deglaciation phase and in some cores the last glacial maximum. The sediments carry a well‐defined characteristic remanent magnetization and have a valuable potential to reconstruct the paleosecular variation (PSV) of the geomagnetic field, including relative paleointensity (RPI) variations. The paleomagnetic data allow reconstruction of past dynamics and amplitude of the geomagnetic field variations at high northern latitudes (75°–76° N). At the same time, the rock magnetic and paleomagnetic data allow a high‐resolution correlation of the sedimentary sequences and a refinement of their preliminary age models. The Holocene PSV and RPI records appear particularly sound, since they are consistent between cores and they can be correlated to the closest regional stacking curves (UK PSV, FENNOSTACK and FENNORPIS) and global geomagnetic model for the last 7 ka (CALS7k.2). The computed amplitude of secular variation is lower than that outlined by some geomagnetic field models, suggesting that it has been almost independent from latitude during the Holocene. Mon, 31 Oct 2011 23:00:00 GMT http://hdl.handle.net/2122/7176 2011-10-31T23:00:00Z http://hdl.handle.net/2122/7035 Title: Ergodicity of the recent geomagnetic field Authors: De Santis, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Qamili, E.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Cianchini, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia Abstract: The geomagnetic field is a fundamental property of our planet: its study would allow us to understand those processes of Earth’s interior, which act in its outer core and produce the main field. Knowledge of whether the field is ergodic, i.e. whether time averages correspond to phase space averages, is an important question since, if this were true, it would point out a strong spatio-temporal coupling amongst the components of the dynamical system behind the present geomagnetic field generation. Another consequence would be that many computations, usually undertaken with many difficulties in the phase space, can be made in the conventional time domain. We analyse the temporal behaviour of the deviation between predictive and definitive geomagnetic global models for successive intervals from 1965 to 2010, finding a similar exponential growth with time. Also going back in time (at around 1600 and 1900 by using the GUFM1 model) confirms the same findings. This result corroborates previous chaotic analyses made in a reconstructed phase space from geomagnetic observatory time series, confirming the chaotic character of the recent geomagnetic field with no reliable prediction after around 6 years from definitive values, and disclosing the potentiality of estimating important entropic quantities of the field by time averages. Although more tests will be necessary, some of our analyses confirm the efforts to improve the representation of the geomagnetic field with more detailed secular variation and acceleration. Tue, 31 May 2011 22:00:00 GMT http://hdl.handle.net/2122/7035 2011-05-31T22:00:00Z http://hdl.handle.net/2122/4071 Title: Are we going towards a global planetary magnetic change? Authors: De Santis, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Qamili, E.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia Editors: De Santis, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Baker, R.; Israel Institute of Technology, Israel; Klug, B.; Univ. of Natural Res. & Applied Life Sciences, Austria; Vanicek, P.; University of New Brunswick, Canada; D'El-Rey Silva, L. J. H.; Universidade de Brasilia, Brazil; Foyo, A.; University of Cantabria, Spain; Ercanoglu, M.; Hacettepe University, Turkey; Dordevic, D.; University of Belgrade, Serbia Abstract: The dipolar part of the geomagnetic field has been decaying rapidly during the last few hundreds of years. In addition to this classical argument, from Information theory applied to geomagnetism, there are some evidences that the recent Earth magnetic field is showing characteristics typical of a reversal in progress. If this is true, many scientific and environmental questions will arise. For instance, it will be of particular interest to monitor the time-space dynamics the South Atlantic Anomaly, where the magnetic field is strongly reduced (a sort of "planetary magnetic hole"). Here we find one of the most favourite places where Low Earth Orbiting (LEO) satellites are lost or present some damages, due to the vicinity of "clouds" of electric particles (Van Allen belts) to the Earth's surface. The decay of the field will also decrease the screening effect to the solar wind and cosmic charges, so enhancing the cosmic radiation illuminating our planet: possible negative consequences are expected in terms of increase of skin cancers. Also important will be the study of the possible evolution of the core dynamics that will be generating this specific condition of the geomagnetic field. Wed, 10 Sep 2008 22:00:00 GMT http://hdl.handle.net/2122/4071 2008-09-10T22:00:00Z http://hdl.handle.net/2122/4070 Title: Environment and Geoscience Authors: De Santis, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Baker, R.; Israel Institute of Technology, Israel; Klug, B.; Univ. of Natural Res. & Applied Life Sciences, Austria; Vanicek, P.; University of New Brunswick, Canada; D'El-Rey Silva, L. J. H.; Universidade de Brasilia, Brazil; Foyo, A.; University of Cantabria, Spain; Ercanoglu, M.; Hacettepe University, Turkey; Dordevic, D.; University of Belgrade, Serbia Editors: De Santis, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Baker, R.; Israel Institute of Technology, Israel; Klug, B.; Univ. of Natural Res. & Applied Life Sciences, Austria; Vanicek, P.; University of New Brunswick, Canada; D'El-Rey Silva, L. J. H.; Universidade de Brasilia, Brazil; Foyo, A.; University of Cantabria, Spain; Ercanoglu, M.; Hacettepe University, Turkey; Dordevic, D.; University of Belgrade, Serbia Abstract: This book contains the proceedings of the 1st WSEAS International Conference on Environmental and Geological Science and Engineering (EG'08) which was held in Malta, September 11-13, 2008. This conference aims to disseminate the latest research and applications in Renewable Energy, Mineral Resources, Natural Hazards and Risks, Environmental Impact Assessment, Urban and Regional Planning Issues, Remote Sensing and GIS, and other relevant topics and applications. The friendliness and openness of the WSEAS conferences, adds to their ability to grow by constantly attracting young researchers. The WSEAS Conferences attract a large number of well-established and leading researchers in various areas of Science and Engineering as you can see from http://www.wseas.org/reports. Your feedback encourages the society to go ahead as you can see in http://www.worldses.org/feedback.htm The contents of this Book are also published in the CD-ROM Proceedings of the Conference. Both will be sent to the WSEAS collaborating indices after the conference: www.worldses.org/indexes In addition, papers of this book are permanently available to all the scientific community via the WSEAS E-Library. Expanded and enhanced versions of papers published in this conference proceedings are also going to be considered for possible publication in one of the WSEAS journals that participate in the major International Scientific Indices (Elsevier, Scopus, EI, ACM, Compendex, INSPEC, CSA .... see: www.worldses.org/indexes) these papers must be of high-quality (break-through work) and a new round of a very strict review will follow. (No additional fee will be required for the publication of the extended version in a journal). WSEAS has also collaboration with several other international publishers and all these excellent papers of this volume could be further improved, could be extended and could be enhanced for possible additional evaluation in one of the editions of these international publishers. Finally, we cordially thank all the people of WSEAS for their efforts to maintain the high scientific level of conferences, proceedings and journals. Wed, 10 Sep 2008 22:00:00 GMT http://hdl.handle.net/2122/4070 2008-09-10T22:00:00Z http://hdl.handle.net/2122/3916 Title: Fluid motions in the Earth’s core inferred from time spectral features of the geomagnetic field Authors: Consolini, G.; Istituto di Fisica dello Spazio Interplanetario, CNR, I-00133 Roma, Italy; De Michelis, P.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Meloni, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia Abstract: The aim of this work is to investigate the time spectral features of the main geomagnetic field fluctuations as measured on the Earth’s surface in connection with a nontraditional turbulent dynamics of the fluid motions in the outer layers of the Earth’s liquid core. The average geomagnetic field spectrum is found to be a power law, characterized by a spectral exponent α≈−11/3, on time scales longer than 5 yr. We discuss the spectral exponent in connection with an intense magnetic field in the Earth’s core and with a vortex coalescence process in a regime of drift-wave turbulence. Mon, 31 Dec 2001 23:00:00 GMT http://hdl.handle.net/2122/3916 2001-12-31T23:00:00Z http://hdl.handle.net/2122/2629 Title: Il nucleo terrestre: il cuore magnetico della Terra Authors: De Santis, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia Abstract: Il campo magnetico terrestre è una proprietà intrinseca del nostro pianeta e di altri oggetti del sistema solare. Il Sole stesso possiede un forte campo magnetico che si inverte quasi ciclicamente ogni 10-11 anni; tale comportamento è visibile attraverso la medesima ciclicità delle macchie solari che denotano sulla superficie l’intensa attività magnetica della nostra stella. Il campo magnetico terrestre è importantissimo per la vita sulla Terra. Esso protegge il pianeta dalle particelle cariche provenienti dal Sole: con la sua presenza si oppone alla forza di questo vento solare che altrimenti spazzerebbe via gran parte dell’atmosfera terrestre, così come probabilmente è già avvenuto in passato con l’atmosfera di Marte. Sat, 31 Dec 2005 23:00:00 GMT http://hdl.handle.net/2122/2629 2005-12-31T23:00:00Z http://hdl.handle.net/2122/1347 Title: The separation of the geomagnetic field originated in the core, in the asthenosphere, and in the crust Authors: Gregori, G. P.; Istituto di Fisica dell’Atmosfera (IFA-CNR), Roma, Italy; and World Laboratory, Lausanne, Switzerland; Dong, W. J.; World Laboratory Scholarship, c/o IFA (CNR), Roma, Italy; Gao, X. Q.; World Laboratory Scholarship, c/o IFA (CNR), Roma, Italy; Gizzi, F. T.; European Commission Scholarship, c/o IFA (CNR), Roma, Italy Abstract: The separation of the field produced by different internal sources can be accomplished by means of the so-called spatial spectrum of the geomagnetic field of internal origin. It is shown how such a rationale, when suitably interpreted, allows to recognize the field that is originated by electric currents that flow either on the Inner-Core Boundary (ICB), or on the Core-Mantle Boundary (CMB), or on the Asthenosphere-Lithosphere Boundary (ALB). It appears crucial, however, to rely on satellite measurements alone, because ground-based and ship- and air-borne records are severely perturbed by the crustal field. Therefore, it is shown, on the basis of a critical reconsideration of a few key-papers in the literature, that the best approach is to avoid mixing together all kinds of measurements. Satellite data are best suited for recognizing the dynamo field, while ground-based, ship- and air-borne records, which are measured much closer to crustal sources, are best suited, after subtraction of the satellite-derived dynamo field, for inferring the geomagnetic anomalies that are to be associated with crustal sources alone. Wed, 31 Mar 1999 22:00:00 GMT http://hdl.handle.net/2122/1347 1999-03-31T22:00:00Z