Gerardo Romano

Flank instability structure of Mt. Etna inferred by a magnetotelluric survey

This paper presents a magnetotelluric (MT) survey of the unstable eastern flank of Mt. Etna. We take thirty soundings along two profiles oriented in the N-S and NW-SE directions, and from these data recover two 2D resistivity models of the subsurface. Both models reveal three major layers in a resistive-conductive-resistive sequence, the deepest extending to 14 km bsl. The shallow layer corresponds to the volcanic cover, and the intermediate conductive layer corresponds to underlying sediments segmented by faults. These two electrical units are cut by E-W-striking faults. The third layer (basement) is interpreted as mainly pertinent to the Apennine-Maghrebian Chain associated with SW-NE-striking regional faults. The detailed shapes of the resistivity profiles clearly show that the NE Rift is shallow-rooted ( 0–1 km bsl), thus presumably fed by lateral dikes from the central volcano conduit. The NW-SE profile suggests by a series of listric faults reaching up to 3 km bsl, then becoming almost horizontal. Toward the SE, the resistive basement dramatically dips (from 3 km to 10 km bsl), in correspondence with the Timpe Fault System. Several high-conductivity zones close to the main faults suggest the presence of hydrothermal activity and fluid circulation that could enhance flank instability. Our results provide new findings about the geometry of the unstable Etna flank and its relation to faults and subsurface structures.

Archeological crop marks identified from Cosmo-SkyMed time series: the case of Han-Wei capital city, Luoyang, China

ABSTRACT The development of spaceborne Synthetic Aperture Radar (SAR) technology declares that the golden era of SAR remote sensing in archeology is approaching; however, nowadays its methodology framework is still lacking due to the inadequate case studies validated by ground-truths. In this study, we investigated the crop marks using multi-temporal Cosmo-SkyMed data acquired in 2013 by applying a two-step decision-tree classifier in conjunction with a spatial analysis in an area of archeological interest nearby the archeological site of Han-Wei capital city (1900–1500 BP), in Luoyang, China. The time-series backscattering anomalies related to the wheat growth cycle were identified and then further validated in two zones by geophysical investigations (Ground Penetration Radar and electrical measurements) and in a third zone by archeological excavations made after the SAR data acquisition. This study provides a new approach for the relic detection, shallowly buried and covered by the crop vegetation, by temporal crop marks on spaceborne SAR images. We also emphasize the necessity to establish a satellite-to-ground methodology framework for the promotion of remote-sensing technology in archeology.

Comment on “Deep resistivity cross section of the intraplate Atlas Mountains (NW Africa): New evidence of anomalous mantle and related Quaternary volcanism”

Citation: Jones, A. G., D. Kiyan, J. Fullea, J. Ledo, P. Queralt, A. Marcuello, A. Siniscalchi, and G. Romano (2012), Commenton “Deep resistivity cross section of the intraplate Atlas Mountains (NW Africa): New evidence of anomalous mantle and relatedQuaternary volcanism,” Tectonics, 31, TC5011, doi:10.1029/2011TC003051.

Remote Sensing and Geophysics for the Study of the Human Past in the Nasca Drainage

This chapters presents and discusses the results of investigations performed by ITACA Mission of CNR in the Nasca drainage basin, including the ceremonial center of Cahuachi, from 2007 to 2014. The employed approach was based on the multiscale and multisensor integration of remote-sensing methods, including geophysics . Most of the applications have been intended for preventive archaeology, in particular, for providing information on the presence of buried sites and structures by identifying different surface characteristics such as arid bare ground in the Pampas and vegetated areas in the river oases. The operational use of earth-observation technologies has been the occasion to develop ad hoc approaches to data acquisition, processing, and interpretation for the detection of earthen buried structures that is a crucial and challenging issue due to the subtle physical contrast between earthen remains and the surrounding subsoil. This made necessary amassing experience in, and the testing of, various techniques to investigate the subsoil by geophysical and remote methods, working side by side with archaeologists, involved in the interpretation of the results. The obtained results have been the discovery of previously unknown sites in the Nasca drainage basin, the identification of buried ritual offering, the characterization of the stepped structure of Templo Sur, and the mapping of areas of archaeological interest.

Dynamics of internal and external origin revealed by a single-site magnetotelluric monitoring

A continuously operating magnetotelluric (MT) system was installed in Agri Valley (Southern Italy) by the Institute of Methodologies for the Environmental Analysis (IMAA) for studying the temporal stability of the electric properties of the subsoil. In a previous work, Balasco et al. (2008) analysed 1-year-long dataset evidencing possible source effects. Such effects are deeply investigated in this work considering almost three years monitoring. Two different types of dynamics are revealed: i) a seasonal fluctuation at short sounding periods, and ii) a behaviour linked to the external geomagnetic activity index at high periods.

QUANTIFYING PERSISTENT BEHAVIOR IN EARTH'S APPARENT RESISTIVITY TIME SERIES

The multiple segmenting method (MSM) has been applied to investigate the scaling behaviour in the Earths 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.

Archaeogeophysical-Based Approach for Inca Archaeology: Overview and one operational application

Even if, in recent decades, the use of remote sensing technologies (from satellite, aerial and ground) for archaeology is stepping into its golden age, in Southern America geophysics for preventive archaeology is more recent and less used than in Europe, Central America and Middle East. In this paper, we provide a brief overview and show the preliminary results obtained from the investigations conducted in Chachabamba (Peru). The archaeological area is located on a strategic terrace overlooking three Inca roads, which served the most important ceremonial centres (including Machu Picchu) of the Urubamba Valley also known as the Sacred Valley. In particular, Chachabamba investigations were conducted with two principal aims: (1) to give new impetus to archaeological research with targeted investigations aimed at improving and completing the site’s knowledge framework; (2) to experiment and validate an archaeogeophysical approach to be reapplied in other sites of the Urubamba valley, including Machu Picchu, having similar characteristics as those found in Chachabamba.

Puquios : New Insights from the Integration of Remote Sensing, GIS-Based Analyses and Geophysical Investigations

The investigations conducted previously on the Nasca puquios, with particular reference to those systematically performed by Schreiber and Lancho Rojas (1995), Schreiber and Lancho Rojas (Los puquios de Nasca: un sistema de galerias filtrantes. Editorial Los Pinos, Lima, 1998), Schreiber and Lancho Rojas (Aguas en el Desierto. Los puquios de Nasca. Fondo Editorial, Lima, Peru, 2006), have had the merit of placing the theme of Nasca water management in the center of debate on the ancient Nasca world. Water has become the crossroads of all the other research lines focused on the influence of environment and climate on the Nasca culture, as well as on the geoglyphs, ceremonial architecture, and settlements. In this cultural framework, some studies based on multitemporal, multiscale, and multisensor analyses have been performed in the Rio Grande de Nasca drainage in order to investigate the interaction between the puquios and environmental conditions, as well as to improve knowledge of the local environmental settings. Herein we present and discuss the investigations, based on the integration of remote sensing, GIS -based analyses, and geophysical prospecting, in the framework of the ITACA mission of the Italian CNR. Outputs from satellite-based investigations, along with all the information already available from previous studies, were the input data used in the statistical spatial analyses and geophysical prospecting. The main findings provided information useful to: (i) improve the current knowledge on the puquios at both intra-site and inter-site levels and their relationship with environmental and human settings, (ii) identify unknown puquios, (iii) and support planning for subsequent archaeological excavations. As a whole, the investigations based on the adopted integrated approach provided new insights into this hyper-arid area which has been the homeland for numerous civilizations, despite the extreme physical environment that presents serious obstacles to human occupation.