P-wave velocity, density and vertical stress magnitude along the crustal Po Plain (northern Italy) from sonic log drilling data

In order to better characterize P-wave velocities for the shallow crust of the Po Plain and surrounding regions, we have selected 64 deep wells mainly located in the plain and also along the Apennine belt and Adriatic coast. In particular, we have analyzed the stratigraphic profiles for all wells, and the available sonic logs (37 out of 64). From these data we have examinated the P-wave velocity trend with depth and estimated rock density following an empirical relationship between sonic velocity and density in sedimentary rocks. Then we have calculated, notably for the first time in a large area of Italy, the overburden stress magnitude for each well. For instance at a depth of 5 km we have found values varying from 105 to 130 MPa moving from the Adriatic coast to the Apennine belt. Consequently, the Apennines belt shows a maximum regional lithostatic gradient of around 26 MPa/km while the Po Plain and Adriatic region have values of around 21 MPa/km. The maximum density value that can be considered for the Apennine crustal belt corresponds to 2.65 g/cm3; in the Po Plain the mean density is around 2.25 g/cm3, while in the Adriatic area the average density has the lowest value in the region at 2.13 g/cm3. Although in this area a 2D crustal P-wave velocity model does not adequately constrain the complicated and uneven tectonics, we have nevertheless established a shallow model consisting of five separate layers. The strength of this paper lies in the possible use of these direct data, together with other derived geological and geophysical information, to build a 3D model of the area

Investor Sentiment and Employment

__Abstract__ We find that investor sentiment should affect a firm's employment policy in a world with moral hazard and noise traders. Consistent with the model's predictions, we show that higher sentiment among US investors leads to: (1) higher employment growth worldwide; (2) lower labor productivity, as the growth in employment is not matched by real value added growth; and (3) positive wage growth in countries with a greater proportion of high-skill labor, but negative wage growth otherwise. We also find evidence that sentiment induces greater labor instability during financial crises, which sheds new light on the view that financial development has a "dark side". Overall, the results suggest that sentiment has real effects, especially in countries that attract more foreign direct investments from the US and that are perceived as more popular among US investors

Hydrogen storage in MgH2 matrices: A study of Mg-MgH2 interface using CPMD code on ENEA-GRID

The remarkable ability of magnesium to store significant quantities of hydrogen, in the form (MgH2), has fostered intense research efforts in the last years in view of its future applications where light and safe hydrogen-storage media are needed. However, further research is needed since Mg has a high operation temperature and slow absorption kinetics that prevent for the moment the use in practical applications. To improve and optimize the performances of this material a detailed knowledge of the hydrogen diffusion mechanism at the atomic level is needed. Experiments can only provide indirect evidences of the atomic rearrangement during the desorption process. For these reasons a detailed computational study of MgH2 is invoked to characterize the dynamics of hydrogen during desorption. Further insights are gained by characterizing the Mg-MgH2 interface which is supposed to play a major role in the hydrogen diffusion during absorption and desorption cycles. By means of accurate ab initio molecular dynamics simulations based on the density-functional theory with norm-conserving pseudopotentials and plane-wave expansion (CPMD code) an interface is designed and studied. Extensive electronic structure calculations are used to characterize the equilibrium properties and the behavior of the surfaces in terms of total energy considerations and atomic diffusion

Active stress field in central Italy: a revision of deep well data in the Umbria region

In this area the active stress from borehole breakout analysis shows a prevalent NE-SW extension, perpendicular to the main tectonic structures, in agreement with stress inferred from earthquake focal mechanisms and with the strain velocity field. A detailed analysis of active stress data allows to infer the influence of active structures on the local stress field orientations. San Donato 1 well shows a minimum horizontal stress orientation N55±22°, in agreement with the regional trend and with the local one influenced by its vicinity to the Alto Tiberina Fault. Whereas Monte Civitello 1 well shows a quite different orientation, N12±29°, due to its different location, more to the east, and to the structures that it crosses. Although the angular difference between the two directions is within the error, to estimate the regional active stress field many borehole data should be analysed or smoothing maps should be evaluated. In fact, each borehole dataset could be influenced by local stress conditions that in some case can be different from the regional trend. The two breakout orientations perfectly depict the regional extension along the axis of the Apennines and also the minimum horizontal stress rotation moving eastward to the area where compression is predominant

Contemporary and concurrent extension and compression in Italy

Contemporary and concurrent extension and compression in Italy Paola Montone1, M. Teresa Mariucci1 and Simona Pierdominici2 1-Istituto Nazionale di Geofisica e Vulcanologia, Rome , Italy 2 – GFZ GeoForschungsZentrum, Potsdam, Germany We present the latest updating and the complete collection of data on the contemporary stress orientations in Italy. Data are relative to different stress indicators: borehole breakouts from deep drillings, crustal earthquake focal mechanisms and fault data. With respect to the previous compilation, performed in 2004, 206 new entries complete the definition of the horizontal stress orientation and tectonic regime in the most part of the territory, and bring new information mainly in Sicily and along the Apenninic belt. With an increase of 37% with respect to the previous compilation, now the global Italian dataset consists of 499 records with a reliable quality for stress maps. The total dataset includes the following active stress indicators: 56% borehole breakouts, 39% single earthquake focal mechanisms, and 5% represented by formal inversions of focal mechanisms, faults and overcoring data. A quality ranking between A and E is assigned to each stress data, with A being the highest quality and E the lowest. Only A-, B- and C-quality stress indicators are considered consistent for analyzing stress patterns. Depth interval of the entire dataset is between 0 to 40 km. The results in map are reported in terms of minimum horizontal stress (Shmin) because most of earthquakes present an extensional regime. Concerning breakouts, their orientations correspond to Shmin; since all the considered faults are normal faults, we assume the Shmin direction as perpendicular to the fault strike when no information on slip direction is available. The achieved results can be summarized in 3 main points: i) in some areas of Italy (Sicily, Friuli and Po Plain in the northern Italy), the alignment of horizontal stresses closely matches the ~N-S direction of ongoing crustal motions with respect to stable European plate. This result can be associated to the first-order stress field that drives the plate movement; ii) along the entire Apenninic belt – from north to south- a diffuse extensional stress regime is clearly showed by a large dataset indicating a NE-SW direction of extension, probably related to a second-order stress field; iii) the stress rotations observed in some areas (i.e., Po Plain minor arcs and Gela thrust front) reflect a complex interaction between first order stress field and local effects, revealing the importance of the inherited tectonic structure orientations. In particular in this work the simultaneous occurrence of different stress regimes is discussed. Finally, we underline that this kind of map is very useful to those many users that work on this topic and/or related ones such as, for instance, geophysical modeling, seismic hazard assessment, rock mechanics laboratory experiments, deep drillings but also on oil and gas well production and construction of nuclear waste deposits

Scientific drilling in a central italian volcanic district

This article introduces the 350m scientific borehole performed in the Colli Albani area. It describes the technical features of the drilling and the on-site measurements, and summarizes the main ongoing researches on data and samples from the borehole

Comparison between active stress field and tectonic structures in Northern Italy, Lombardy Region

The aim of this work is to understand the complex pattern of active stress field orientations revealed by borehole breakout analysis with respect to the tectonic structures in a wide region of Northern Italy. The area is located in the central-western part of the Po Plain between the south verging Southern Alps structures and the north verging buried folds and thrusts of the Monferrato and Emilia arcs. Little information concerning the active stress field is available because of the low seismicity level and the thick layer of sediments that covers the entire zone. A detailed borehole breakout analysis has been performed in 36 wells with depths ranging from 2.2 to 7.3 km, whose data have been supplied by Eni. Breakout analysis determined the minimum and maximum horizontal stress directions (Shmin and SHmax). The results show a very complex pattern, pointing out that the stress field is not uniform. In this area the regional stress field seems not «strong» enough, compared to the local one, so most of the wells detect only the local field. This work contributes to clarify the various Shmin orientations observed in this area, pointing out at wide scale, a general compression in NNE-SSW direction in this complex region

Palaeomagnetic results from an archaeological site near Rome (Italy): new insights for tectonic rotation during the last 0.5 Myr

Approximately 20 km north-east of Rome, along the modern trace of the Tiburtina road, recent archaeological diggings have brought to light a system of aqueduct galleries constructed by Roman engineers. This site falls inside the Acque Albule Basin, a travertine plateau Upper Pleistocene in age, that has been interpreted as a rhombshaped pull-apart basin created by strike-slip faulting within a N-S shear zone. This study provides evidence that two narrow water channels of this aqueduct system were significantly deformed by tectonic movement that occurred subsequent to their construction (II-III century A.D.). The geometry of the deformation pattern is compatible with that expected for a shear zone bounded by N-S oriented, right-lateral faults. The palaeomagnetic study of the volcanic formation («Pozzolane Rosse» Formation, 457± 4 kyr) containing the Roman aqueduct system evidences significant clockwise rotation around sub-vertical axis, consistent with the above-mentioned tectonic style