Changing the global environment perspectives on human involvement     

Daniel B. Botkin  Margriet F. Caswell  John E. Estes  Angelo A. Orio 《国际地球制图》2013,28(3)

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Pelagic primary production in the Algero-Provençal Basin by means of multisensor satellite data: focus on interannual variability and its drivers     

Antonio Olita  Roberto Sorgente  Alberto Ribotti  Leopoldo Fazioli  Angelo Perilli 《Ocean Dynamics》2011,61(7):1005-1016

In this work, we make use of satellite estimates of chlorophyll a, photosynthetically active radiation and sea surface temperatures, to compute regional estimates of primary production integrated throughout the euphotic layer for the Algero-Provençal Basin, by means of a modified version of the vertically generalized production model. The seasonal and interannual variability of the primary production has been analysed over the decade 1997–2007. Empirical orthogonal functions analysis has been applied to decompose the variability of the primary production dataset in orthogonal modes of variability. The seasonal signal is distributed between the two first modes of variability, temporally shifted each other and respectively related to the northern (early spring) and the southern (winter) part of the basin. We found a minimum of the annual production in 2003, when a summer heatwave strongly enhanced the stratification of surface waters, further limiting the injection of nutrients into the surface layers. Maxima in the annual series are found in 1999 and 2005, due to two particularly intense and extended (in space) spring-blooms in the northern part of the basin. These two maxima, clearly identified in space and time by EOF analysis (EOF1 and EOF3), are related to strong mistral-wind interannual events occurring during winters of 1999 and 2005, preceding the blooms by some few months. We found that these production maxima are due both to a more intense production in the usual blooming area (shown by EOF1–PC1) as well as to an exceptional local production in the eastern side of the basin, off the Corsica western coasts (EOF3–PC3). Previous observations of exceptional deep-water formation events in 1999 and 2005, with easterly spots close to the primary production-observed anomalies, and the meridional character of the mistral 1999 and 2005 peaks both support the idea that such eastern PP interannual maxima would be actually due to exceptional production more than to an easterly advection of biomass from the usual bloom area. Finally, the potential link of the observed features with large-scale atmospheric forcing is discussed, and a potential relation of such interannual events with the East Atlantic pattern is drawn.  相似文献   

High precision tilt observation at Mt. Etna Volcano,Italy     

Angelo Ferro  Salvatore Gambino  Stefano Panepinto  Giuseppe Falzone  Giuseppe Laudani  Bernard Ducarme 《Acta Geophysica》2011,59(3):618-632

In 2007–2008, we installed on Mt. Etna two deep tilt stations using high resolution, self-leveling instruments. These installations are a result of accurate instrument tests, site selection, drilling and sensor positioning that has allowed detecting variations related to the principal diurnal and semidiurnal tides for first time on Mt. Etna using tilt data.  相似文献   

Deglaciation of the western margin of the Barents Sea Ice Sheet — A swath bathymetric and sub-bottom seismic study from the Kveithola Trough     

Michele Rebesco  Yanguang Liu  Angelo Camerlenghi  Monica Winsborrow  Jan Sverre Laberg  Andrea Caburlotto  Paolo Diviacco  Daniela Accettella  Chiara Sauli  Nigel Wardell  Isabella Tomini 《Marine Geology》2011,279(1-4):141-147

Kveithola Trough, an E–W trending glacial trough in the NW Barents Sea, was surveyed for the first time during the EGLACOM cruise of R/V OGS-Explora in summer 2008. Swath bathymetry shows that the seafloor is characterized by E–W trending mega-scale glacial lineations (MSGL) that record a fast flowing ice stream draining the Svalbard/Barents Sea Ice Sheet (SBIS) during the Last Glacial Maximum (LGM). MSGL are overprinted by transverse sediment ridges about 15 km apart which give rise to a staircase axial profile of the trough. Such transverse ridges are interpreted to be grounding-zone wedges (GZWs) formed by deposition of subglacial till during episodic ice stream retreat. Sub-bottom (CHIRP) and multi-channel reflection seismic data show that the present-day morphology is largely inherited from the palaeo-seafloor topography at the time of deposition of the transverse ridges, overlain by a draping glaciomarine unit which in places is over 15 m thick. Our data allow the reconstruction of depositional processes which accompanied deglaciation of the Spitsbergen Bank area. The sedimentary drape deposited on top of the GZWs is suggested to have accumulated at a very high rate, (on average in the order of 1–1.5 m ka^?1) and therefore may potentially preserve a high-resolution palaeoclimatic record of deglaciation and post-glacial conditions in this sector of the Barents Sea.  相似文献   

Helmert's projection of a ground point onto the rotational reference ellipsoid in topocentric cartesian coordinates     

N. Crocetto  P. Russo 《Journal of Geodesy》1994,69(1):43-48

Summary In order to derive the ellipsoidal height of a point P_t, on the physical surface of the earth, and the direction of ellipsoidal normal through P_t, we presente here an iterative procedure rapidly convergent to compute, in a topocentric Cartesian system, the coordinates of Helmert's projection of the ground point P_t onto the reference ellipsoid of revolution .We derive as well the cofactor matrix of total vector of the topocentric coordinates of the above ground point and of its Helmert's projection so that to compute the variance of ellipsoidal height.  相似文献   

Dealing with deindustrialization: adaptive resilience in American Midwestern Regions,by Margaret Cowell     

John Russo 《Urban geography》2017,38(2):315-316

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Pedestrian hazard criteria for flooded urban areas     

B. Russo  M. Gómez  F. Macchione 《Natural Hazards》2013,69(1):251-265

Urban floods are sudden phenomena normally characterized by short flooding durations and devastating effects due to the high concentrations of persons, goods, and properties located in urban areas. In these cases, uncontrolled runoff can flow on urban streets, creating a significant hazard for pedestrians and vehicles. The safety of people can be compromised when they are exposed to flows that exceed their ability to remain standing or to traverse flow paths. With the aim of studying the stability of pedestrians in flooded street during storm events, a model representing an urban street in real scale was designed and built. Following a specific protocol that considering several flow rates (up to 500 l/s) and different longitudinal slopes (up to 10 %), 834 tests, using 23 human subjects, were carried out in good and poor light conditions. Hazard conditions were classified into three groups (low, medium, and high), and the parameters for which these conditions occurred were recorded. Results showed that for subjects weighing 50–60 daN (50–60 kg mass) and flow depths between 9 and 16 cm, velocities of 1.5–2 m/s can generate loss of stability due to phenomena of dragging or overturning. Empirical expressions were proposed to relate human subject characteristics (weight and height) and limiting flow conditions at which loss of stability occurs.  相似文献   

Rough evaluation of the water-inflow discharge in abandoned mining tunnels using a simplified water balance model: the case of the Cogne iron mine (Aosta Valley, NW Italy)     

Stefano Lo Russo  Loretta Gnavi  Daniele Peila  Enrico Suozzi 《Environmental Earth Sciences》2013,70(6):2753-2765

One of the most complex hydrogeological problems in the design and maintenance of drainage systems in abandoned mining sites is quantifying the maximum water infiltration and, therefore, the amount that is potentially drainable by the tunnels. This problem is compounded when water-inflow data are limited or lacking. The aim of the study was to present a single but reliable model for making this evaluation; this model was applied to the case history of the abandoned Cogne iron ore mining complex (Western Alps, Aosta Valley Region, NW Italy). The study focused on quantifying the amount of water infiltrating into the mine drifts, using a water balance model in a Geographic Information System (GIS) environment. In the model, five different infiltration scenarios were calculated, including a detailed analysis of rainfall data, snow density and thickness (Snow Water Equivalent calculation), and melting periods. The maximum water discharge that could affect the mine tunnels was, therefore, determined under several scenarios of normal precipitation conditions and during heavy rainfall, including the case of the Cogne valley flood in October 2000, used as a reference for the limit conditions. Taking into account the various approximations considered, the results can be considered a good indication of the magnitude of the total amount of water that should be drained out through abandoned mine drifts and in the drainage network during implementation of final closure of the mine.  相似文献   

Relevant features of the valley seismic response: the case study of Tuscan Northern Apennine sector     

G. Vessia  S. Russo 《Bulletin of Earthquake Engineering》2013,11(5):1633-1660

The so called “valley effect” relates to the typical seismic response of basin shaped bedrock filled by quaternary sediments. It is an aspect of the renown “local seismic effect” that shall be taken into account when dealing with microzoning studies. Several experimental surveys and numerical simulations performed worldwide over the last 40 years, confirmed that valley responses under seismic excitations show common features in various geological contexts as far as the sedimentary valleys (e.g. alluvial and lacustrine plains), the intermountain valleys (e.g. alpine valleys) and graben shaped basins. Such features mainly depend on the basin geometry, referred to as the shape ratio SR, and the sediment and basin impedance contrast IC. Although researchers agree on the prominent role of local seismic effects for interpreting erratic damages caused by seismic shaking in urbanized areas, no fully shared strategies have been identified for taking into account valley effect within microzoning studies. In this paper, a numerical simulations on three models of trapezoidal shaped basins have been performed. These valley models relate to sediments and basins detected within the Tuscany Region territory during the VEL project. Results, in terms of the amplification index $\text{ F }_{\mathrm{A}}$ F A have been provided. Three “valley effect charts” for various SR and IC values have been propose for taking into account the local seismic effects due to the basin amplifications within microzoning maps.  相似文献   

Shrinking ‘Smart’?: Urban Redevelopment and Shrinkage in Youngstown,Ohio     

James Rhodes  John Russo 《Urban geography》2013,34(3):305-326

Abstract

This article analyzes the impact of the much-heralded Youngstown 2010 Plan and the enacting of a program of “controlled” or “managed” shrinkage. It is argued that while the program of redevelopment has had an impact on Youngstown and its national image, it represents an exclusionary project that has centered on redeveloping downtown areas and neglected many city neighborhoods which continue to experience high levels of unemployment, vacancy, and crime. The analysis is situated in relation to the contemporary literature on “shrinking cities.” Youngstown's experience raises critical questions regarding the nature of the challenges facing shrinking cities, the constraints on actions available to them due to state and federal funding, and the coherence of the concept of “smart shrinkage.”  相似文献