Search results for "Ocean"

Extended Environmental Contour Methods for Long-Term Extreme Response Analysis of Offshore Wind Turbines1

2020

Abstract Environmental contour method is an efficient method for predicting the long-term extreme response of offshore structures. The traditional environmental contour is obtained using the joint distribution of mean wind speed, significant wave height, and spectral peak period. To improve the accuracy of traditional environmental contour method, a modified method was proposed considering the non-monotonic aerodynamic behavior of offshore wind turbines. Still, the modified method assumes constant wind turbulence intensity. In this paper, we extend the existing environmental contour methods by considering the wind turbulence intensity as a stochastic variable. The 50-year extreme responses …

Environmental and depositional controls on laminated freshwater carbonates: An example from the Roman aqueduct of Patara, Turkey

2013

Carbonate deposits in aqueducts are a new high-resolution data source for environmental changes during the time of the Roman Empire, notably in the fields of palaeoclimate and spring hydrology. In order to distinguish environmental effects from those related to depositional setting, laminated carbonate deposits were compared along the entire length of an ancient aqueduct channel at Patara, Turkey. The carbonate deposits, up to 80mm in thickness, are composed of lamina couplets up to 1mm thick of alternating porous microspar and dense, columnar sparite. The former formed in the dry, warm season and the latter in the wet, cool season. The presence of biofilms seems to play a role in the devel…

Benthic foraminifera as indicators of relative sea-level fluctuations: Paleoenvironmental and paleoclimatic reconstruction of a Holocene marine succe…

2017

This study presents the results of an integrated stratigraphic analysis conducted on a marine gravity core (MSK-12 C4) recovered from the outer continental shelf (82 mwater depth) of western Calabria, ~2.6 km, NE of Capo Vaticano (Eastern Tyrrhenian margin). The gravity core MSK-12 C4 recovered a stratigraphic succession of 4.18 m beneath the seafloor representing the last ~11.1 ka. Sedimentological analysis, micropaleontological quantitative analysis on benthic foraminiferal assemblages, tephrostratigraphy, sequence stratigraphic analysis of high resolution reflection seismic data recorded in the core site area and AMS 14C absolute age determinations allowed reconstructing the marine recor…

Sea-level changes during the last 41,000 years in the outer shelf of the southern Tyrrhenian Sea: Evidence from benthic foraminifera and seismostrati…

2011

Abstract An integrated high resolution study based both on a seismostratigraphic approach and on a sedimentary core (VIB 10), collected in the outer shelf (127 m depth) from the southern Tyrrhenian Sea (Gulf of Termini, Sicily), provides new data about climatic, eustatic and paleoenvironmental changes during the last ∼41,000 years. The results based on the interpretation of a seismic profile, on benthic foraminifera assemblages and on δ18O records, allowed recognition of two drastic sea-level falls during the Last Glacial Maximum (LGM) and the Younger Dryas (YD). The short deglacial event, between LGM and YD, known as Bolling/Allerod, played an important role in the sea-level rise that prod…

Signals from the deep-sea: Genetic structure, morphometric analysis, and ecological implications of Cyclothone braueri (Pisces, Gonostomatidae) early…

2020

Abstract Cyclothone braueri (Stomiiformes, Gonostomatidae) is a widely distributed fish inhabiting the mesopelagic zone of marine tropical and temperate waters. Constituting one of the largest biomasses of the ocean, C. braueri is a key element in most of the ecological processes occurring in the twilight layer. We focused on the ecological processes linked to early life stages in relation to marine pelagic environmental drivers (temperature, salinity, food availability and geostrophic currents) considering different regions of the Central Mediterranean Sea. A multivariate morphometric analysis was carried out using six parameters with the aim of discerning different larval morphotypes, whi…

Influence of artificial reefs on the surrounding infauna: Analysis of meiofauna

2002

We adopted a bottom-up approach in studying the effect of two artificial reefs in contrasting environmental conditions (sandy-mud and meso-eutrophic in the Adriatic Sea versus coarse sands and oligotrophic in the Tyrrhenian Sea) on the surrounding environment by assessing changes in the meiofauna. The spatial distribution of meiofaunal assemblages was established along a transect running from within each reef to well outside its direct sphere of influence, along with information on the trophic conditions of sediments (chloropigments, proteins, carbohydrates and total organic matter). Although total densities were significantly higher in the Adriatic than in the Tyrrhenian, the meiofauna dis…

Modelling regional-scale attenuation across Italy and the Tyrrhenian Sea

2021

Abstract Modelling regional-scale attenuation of seismic waves at ~1 Hz is challenging, especially when these waves propagate across both continental and oceanic crust. Recent developments in seismic imaging and modelling have provided us with the computational tools necessary to reconstruct these mixed settings using deterministic (coherent) and stochastic (coda) information. Here, we present new tomographic maps of coda-attenuation for both the Italian peninsula and the Tyrrhenian Sea. Kernel-based coda attenuation imaging in the diffusive approximation is tested in the oceanic environment, highlighting a non-diffusive behaviour across the Southern Tyrrhenian Sea. Joint deterministic and …

A 4500 year record of palaeomagnetic secular variation and relative palaeointensity from the Tyrrhenian Sea

2020

A marine sediment core from the western Mediterranean provides a newhigh-resolution 4,500-year record of palaeomagnetic secular variation and relativepalaeointensity. In 2013, the 7.1-metre C5 core was recovered from the TyrrhenianSea as part of the NextData climate data project. The coring site, 15 km offshorefrom the Volturno river mouth, is well-located to record combined marine andterrestrial palaeoclimatic influences, and the fine-grained, rapidly deposited sedimentsare effective palaeomagnetic recorders. We investigate the palaeomagnetic field direction and strength recorded in the core, which provide a valuable high-resolution recordof Holocene geomagnetic variation in the area. Usin…

Climatic variability and anthropogenic signatures in the Gulf of Salerno (southern-eastern Tyrrhenian Sea) during the last half-millennium

2012

UNCLOS and territorialization of the seas: the case of Indian and Pacific Oceans

2017

The 200-nautical-mile Exclusive Economic Zone created by the 1982 UNCLOS regime generates conflict in areas where the distance between opposite national coasts is less than 400 nautical miles and in marginal seas surrounded by many states and with islands. This is the case of the marginal seas in the Indian and Pacific Oceans. In particular, the EEZ regime has proved troublesome in the South China Sea, leading some authors to ask whether it has actually strengthened or undermined peace and cooperation. Does the problem really lie with UNCLOS? My purpose hereby is to explain that, in truth, UNCLOS is a milestone in the process of territorialization of the seas . The EEZ regime represents the…