38 research outputs found
Thermal Structure of the Northern Outer Albanides and Adjacent Adriatic Crustal Sector, and Implications for Geothermal Energy Systems
Using an analytical methodology taking into account heat flow density data, frictional heating, temperature variations due to the re-equilibrated conductive state after thrusting and geological constrains, we calculated surface heat flow, geotherms and isotherms along a balanced and restored regional geological cross-section. Our results highlight the impact of frictional heating produced by thrusts on the thermal structure of the study area, leading to a raising of the isotherms both in the inner Albanides to the E and in the Adriatic sector offshore. Minimum values of Qs in the surroundings of Tirana and the reconstructed 2D thermal structure suggest less favorable conditions for exploitation of geothermal energy, besides the direct use (Borehole Heat Exchanger-Geothermal Heat Pump systems). Nevertheless, the occurrence of the "Kruja geothermal zone", partially overlapping this area and including hot spring manifestations, emphasize the structural control in driving hot fluids to the surface with respect to the regional thermal structure
Thermal structure of the northern outer Albanides and adjacent Adriatic crustal sector, and implications for geothermal energy systems
none8sìopenSantini, S.; Basilici, M.; Invernizzi, C.; Mazzoli, S.; Megna, A.; Pierantoni, P.P.; Spina, V.; Teloni, S.Santini, S.; Basilici, M.; Invernizzi, C.; Mazzoli, S.; Megna, A.; Pierantoni, P. P.; Spina, V.; Teloni, S
Using a coherent hydrophone array for observing sperm whale range, classification, and shallow-water dive profiles
Sperm whales in the New England continental shelf and slope were passively localized, in both range and bearing, and classified using a single low-frequency (<2500 Hz), densely sampled, towed horizontal coherent hydrophone array system. Whale bearings were estimated using time-domain beamforming that provided high coherent array gain in sperm whale click signal-to-noise ratio. Whale ranges from the receiver array center were estimated using the moving array triangulation technique from a sequence of whale bearing measurements. Multiple concurrently vocalizing sperm whales, in the far-field of the horizontal receiver array, were distinguished and classified based on their horizontal spatial locations and the inter-pulse intervals of their vocalized click signals. The dive profile was estimated for a sperm whale in the shallow waters of the Gulf of Maine with 160 m water-column depth located close to the array's near-field where depth estimation was feasible by employing time difference of arrival of the direct and multiply reflected click signals received on the horizontal array. By accounting for transmission loss modeled using an ocean waveguide-acoustic propagation model, the sperm whale detection range was found to exceed 60 km in low to moderate sea state conditions after coherent array processing.National Science Foundation (U.S.)United States. Office of Naval Researc
Individual, unit and vocal clan level identity cues in sperm whale codas
Fieldwork was supported by Discovery and Equipment grants to H.W. from the Natural Sciences and Engineering Research Council of Canada (NSERC) and the Whale and Dolphin Conservation Society. S.G. and L.R. were supported by the Marine Alliance for Science and Technology for Scotland (MASTs) pooling initiative and their support is gratefully acknowledged. MASTs is funded by the Scottish Funding Council (grant reference HR09011) and contributing institutions. S.G. was also supported by an NSERC Postgraduate Scholarship (PGS-M), an NSERC Canadian Graduate Scholarship (CGS-D), the Izaak Killam Memorial Scholarship, the Patrick F. Lett Fund, the Dalhousie’s Presidents Award, and an FNU fellowship for the Danish Council for Independent Research from the Ministry of Higher Education and Science supplemented by a Sapere Aude Research Talent Award.The ‘social complexity hypothesis’ suggests that complex social structure is a driver of diversity in animal communication systems. Sperm whales have a hierarchically structured society in which the largest affiliative structures, the vocal clans, are marked on ocean-basin scales by culturally transmitted dialects of acoustic signals known as ‘codas’. We examined variation in coda repertoires among both individual whales and social units—the basic element of sperm whale society—using data from nine Caribbean social units across six years. Codas were assigned to individuals using photo-identification and acoustic size measurement, and we calculated similarity between repertoires using both continuous and categorical methods. We identified 21 coda types. Two of those (‘1+1+3’ and ‘5R1’) made up 65% of the codas recorded, were shared across all units and have dominated repertoires in this population for at least 30 years. Individuals appear to differ in the way they produce ‘5R1’ but not ‘1+1+3’ coda. Units use distinct 4-click coda types which contribute to making unit repertoires distinctive. Our results support the social complexity hypothesis in a marine species as different patterns of variation between coda types suggest divergent functions, perhaps representing selection for identity signals at several levels of social structure.Publisher PDFPeer reviewe
Immunogenicity of viral vaccines in the italian military
Military personnel of all armed forces receive multiple vaccinations and have been doing so since long ago, but relatively few studies have investigated the possible negative or positive interference of simultaneous vaccinations. As a contribution to fill this gap, we analyzed the response to the live trivalent measles/mumps/rubella (MMR), the inactivated hepatitis A virus (HAV), the inactivated trivalent polio, and the trivalent subunits influenza vaccines in two cohorts of Italian military personnel. The first cohort was represented by 108 students from military schools and the second by 72 soldiers engaged in a nine-month mission abroad. MMR and HAV vaccines had never been administered before, whereas inactivated polio was administered to adults primed at infancy with a live trivalent oral polio vaccine. Accordingly, nearly all subjects had baseline antibodies to polio types 1 and 3, but unexpectedly, anti-measles/-mumps/-rubella antibodies were present in 82%, 82%, and 73.5% of subjects, respectively (43% for all of the antigens). Finally, anti-HAV antibodies were detectable in 14% and anti-influenza (H1/H3/B) in 18% of the study population. At mine months post-vaccination, 92% of subjects had protective antibody levels for all MMR antigens, 96% for HAV, 69% for the three influenza antigens, and 100% for polio types 1 and 3. An inverse relationship between baseline and post-vaccination antibody levels was noticed with all the vaccines. An excellent vaccine immunogenicity, a calculated long antibody persistence, and apparent lack of vaccine interference were observed
Shallow food for deep-divers:Â dynamic foraging behavior of male sperm whales in a high latitude habitat.
Groups of female and immature sperm whales live at low latitudes and show a stereotypical diving and foraging behavior with dives lasting about 45 min to depths of between 400 and 1200 in. In comparison, physically mature male sperm whales migrate to high latitudes where little is known about their foraging behavior and ecology. Here we use acoustic recording tags to study the diving and acoustic behavior of male sperm whales foraging off northern Norway. Sixty-five hours of tag data provide detailed information about the movements and sound repertoire of four male sperm whales performing 83 dives lasting between 6 and 60 min. Dives ranged in depth between 14 and 1860 in, with a median depth of 175 in, and 92% of the surfacings lasted less than 15 min. The four whales clicked for an average 91% (SD = 10) of the dive duration, where the first usual click was produced at depths ranging between 4 and 218 in and the last usual click at depths ranging between I and 1114 in. Echolocation buzzes, which are used as an indication of prey capture attempts, were emitted at depths between 17 and 1860 in, during both the descent and ascent phase of deep dives. The foraging behavior varied markedly with depth, with the timing and duration of prey capture attempts during shallow dives suggesting that the whales target more sparsely distributed prey. In contrast, deep dives involve frequent prey capture attempts and seem to target more dense food layers. The evidence of exploitation of different food layers, including epipelagic prey, is consistent with the hypothesis that male sperm whales may migrate to high latitudes to access a productive, multi-layered foraging habitat. (C) 2007 Published by Elsevier B.V.</p
Shallow food for deep-divers:Â dynamic foraging behavior of male sperm whales in a high latitude habitat.
Groups of female and immature sperm whales live at low latitudes and show a stereotypical diving and foraging behavior with dives lasting about 45 min to depths of between 400 and 1200 in. In comparison, physically mature male sperm whales migrate to high latitudes where little is known about their foraging behavior and ecology. Here we use acoustic recording tags to study the diving and acoustic behavior of male sperm whales foraging off northern Norway. Sixty-five hours of tag data provide detailed information about the movements and sound repertoire of four male sperm whales performing 83 dives lasting between 6 and 60 min. Dives ranged in depth between 14 and 1860 in, with a median depth of 175 in, and 92% of the surfacings lasted less than 15 min. The four whales clicked for an average 91% (SD = 10) of the dive duration, where the first usual click was produced at depths ranging between 4 and 218 in and the last usual click at depths ranging between I and 1114 in. Echolocation buzzes, which are used as an indication of prey capture attempts, were emitted at depths between 17 and 1860 in, during both the descent and ascent phase of deep dives. The foraging behavior varied markedly with depth, with the timing and duration of prey capture attempts during shallow dives suggesting that the whales target more sparsely distributed prey. In contrast, deep dives involve frequent prey capture attempts and seem to target more dense food layers. The evidence of exploitation of different food layers, including epipelagic prey, is consistent with the hypothesis that male sperm whales may migrate to high latitudes to access a productive, multi-layered foraging habitat. (C) 2007 Published by Elsevier B.V.</p
Evolution and History of Filling of Early Pleistocene, Coarse-Grained Slope Canyons (Peri-Adriatic Basin, Central Italy)
The early Pleistocene stratigraphic succession of the Peri-Adriatic Basin, eastern central Italy, records the filling of an elongate, north-south
oriented piggy-back basin located east of the growing Apennine fold-thrust belt. During the Gelasian (2.58-1.80 Ma), gravel- and sand-sized
sediments derived from the central Apennines were abundantly supplied into the basin through a series of transverse to longitudinal slope
erosional fairways. These sediment conduits are preserved in the rock record as a series of exceptionally exposed canyon-fill successions that provide a rare opportunity to evaluate, from an outcrop perspective, how this type of deepwater depositional system evolves and fills under the indirect effects of glacio-eustatic sea-level changes. The present study uses stratigraphic sections, photopanels, paleocurrent data, and careful lithological mapping to constrain the internal organization of four of these canyon fills, which we refer to as the Ascensione, Castignano, Offida, and Notaresco canyons. A detailed facies analysis suggests that a variety of subaqueous gravity flows were involved in sediment transport and deposition, including slumps, cohesive debris flows, and high- and low-density turbidity currents.
Four main lithofacies that reflect major depositional elements have been identified within the canyon-fill successions and are: (i) clastsupported conglomerates (gravel-rich channel complexes); (ii) medium- to thick-bedded sandstones (channel terminus lobes); (iii) medium- to very thin-bedded sandstones (levee-overbank); (iv) pebbly mudstones and chaotic beds (mudstone-rich mass-transport deposits). The canyon fill strata are organized in lithofacies sequences that tend to follow a predictable pattern and to define vertically stacked fining-upward packages, resulting in highly cyclic successions. Each of these fining-upward packages comprises the sedimentary record of discrete phases of canyon activity, showing transition from a higher energy depositional style to a lower energy mode of sedimentation interrupted by a period of erosion and bypass of sediment to areas further downslope. These recurring fluctuations in canyon activity and sedimentary regime are thought to be related to the switching on and off of coarse clastic sediments to the deepwater basin that, in turn, likely resulted from the contemporary glacio-eustatic changes in sea level
Seismogenic fault system of the mw 6.4 november 2019 albania earthquake: New insights into the structural architecture and active tectonic setting of the outer albanides
A seismic sequence that affected the Durrës region in late 2019 to early 2020 sheds new light on the structural architecture and active tectonic setting of the northern outer Albanides. Stress inversion analysis using focal mechanisms confirms that the area is dominated by ENE-trending horizontal maximum compression. The seismogenic sources consist mainly of ENE-dipping thrust faults roughly parallel to the coastline. The hypocentre distribution indicates that most of the earthquakes, including the Mw 6.4 main shock, nucleated within the basement, with only some of the shallow aftershocks tending to cluster around the deeper portion of previously identified seismogenic structures within the sedimentary cover. Our results, unravelling for the first time the fundamental role of deeply rooted, crustal ramp-dominated thrusting in seismogenesis, imply a profound reconsideration of the seismotectonic setting of the region in terms of a correct assessment of seismic hazard in this densely populated area of Albania