ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Elsevier  (203,197)
  • American Chemical Society  (55,090)
  • Alfred Wegener Institute for Polar and Marine Research & German Society of Polar Research
  • 2015-2019  (258,299)
  • 1950-1954
  • 2018  (258,299)
Collection
Publisher
Years
Year
  • 1
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Physics Letters B 294 (1992), S. 466-478 
    ISSN: 0370-2693
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Physics
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Physics Letters B 317 (1993), S. 474-484 
    ISSN: 0370-2693
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Physics
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Publication Date: 2020-11-18
    Description: The Pomici di Avellino eruption is the Plinian event of Vesuvius with the highest territorial impact. It affected an area densely inhabited by Early Bronze Age human communities and resulted in the long- term abandonment of an extensive zone surrounding the volcano. Traces of human life beneath the eruption products are very common throughout the Campania Region. A systematic review of the available archaeological data, the study of geological and archaeological sequences exposed in excava- tions, and the reconstruction of the volcanic phenomena affecting single sites has yielded an under- standing of local effects and their duration. The archaeological and volcanological analyses have shown that the territory was rapidly abandoned before and during the eruption, with rare post-eruption at- tempts at resettlement of the same sites inhabited previously. The definition of the distribution and stratigraphy of alluvial deposits in many of the studied sequences leads us to hypothesise that the scarce presence of humans during phases 1 and 2 of the Middle Bronze Age in the wide area affected by the eruption was due to diffuse phenomena of remobilisation of the eruption products, generating long- lasting alluvial processes. These were favoured by the deposition of loose fine pyroclastic material on the slopes of the volcano and the Apennines, and by climatic conditions. A significant resettlement of the territory occurred only hundreds of years after the Pomici di Avellino eruption, during phase 3 of the Middle Bronze Age. This study show the role of volcanic and related phenomena from a Plinian event in the settlement dynamics of a complex territory like Campania.
    Description: Published
    Description: 231-244
    Description: 1V. Storia eruttiva
    Description: 5V. Dinamica dei processi eruttivi e post-eruttivi
    Description: 6V. Pericolosità vulcanica e contributi alla stima del rischio
    Description: JCR Journal
    Keywords: Plinian eruption Eruption impact ; Volcanoclastic mass flow ; Vesuvius ; Bronze Age ; Eruption impact
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Publication Date: 2020-12-21
    Description: During the last few decades, 4D volcano gravimetry has shown great potential for illuminating subsurface processes at active volcanoes (including some that might otherwise remain “hidden”), especially when combined with other methods (e.g., ground deformation, seismicity, and gas emissions). By supplying information on changes in the distribution of bulk mass over time, gravimetry can provide unique information regarding such processes as magma accumulation in void space, gas segregation at shallow depths, and mechanisms driving volcanic uplift and subsidence. Despite its potential, 4D volcano gravimetry is an underexploited method, not widely adopted by volcano researchers or observatories. The cost of instrumentation and the difficulty in using it under harsh environmental conditions is a significant impediment to the exploitation of gravity at many volcanoes. In addition, retrieving useful information from gravity changes in noisy volcanic environments is a major challenge. While these difficulties are not trivial, neither are they insurmountable; indeed, creative efforts in a variety of volcanic settings highlight the value of 4D gravimetry for understanding hazards as well as revealing fundamental insights into how volcanoes work. Building on previous work, we provide a comprehensive review of 4D volcano gravimetry, including discussions of instrumentation, modeling and analysis techniques, and case studies that emphasize what can be learned from, campaign, continuous, and hybrid gravity observations. We are hopeful that this exploration of 4D volcano gravimetry will excite more scientists about the potential of the method, spurring further application, development, and innovation.
    Description: Published
    Description: 146-179
    Description: 4V. Dinamica dei processi pre-eruttivi
    Description: JCR Journal
    Keywords: time-variable microgravimetry ; volcano gravimetry
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Publication Date: 2021-03-16
    Description: The Nevado del Ruiz volcano is considered one of the most active volcanoes in Colombia, which can potentially threaten approximately 600,000 inhabitants. The existence of a glacier and several streams channelling in some main rivers, flowing downslope, increases the risk for the population living on the flank of the volcano in case of unrest, because of the generation of lahars and mudflows. Indeed, during the November 1985 subplinian eruption, a lahar generated by the sudden melting of the glacier killed twenty thousand people in the town of Armero. Moreover, the involvement of the local hydrothermal system has produced in the past phreatic and phreatomagmatic activity, as occurred in 1989. Therefore, the physico-chemical conditions of the hydrothermal system as well as its contribution to the shallow thermal groundwater and freshwater in terms of enthalpy and chemicals require a close monitoring. The phase of unrest occurred since 2010 and culminated with an eruption in 2012, after several years of relative stability, stillmaintains amoderate alert, as required by the high seismicity and SO2 degassing. In October 2013, a sampling campaign has been performed on thermal springs and stream water, located at 2600–5000 m of elevation on the slope of Nevado del Ruiz, analyzed for water chemistry and stable isotopes. Some of these waters are typically steam-heated (low pH and high sulfate content) by the vapour probably separating from a zoned hydrothermal system. By applying a model of steam-heating, based on mass and enthalpy balances, we have estimated themass rate of hydrothermal steam discharging in the different springs. The composition of the hottest thermal spring (Botero Londono) is probably representative of a marginal part of the hydrothermal system, having a temperature of 250 °C and low salinity (Cl ~1500 mg/l), which suggest, along with the retrieved isotope composition, a chiefly meteoric origin. The vapour discharged at the steam vent “Nereidas” (3600 m asl) is hypothesized to be separated from a high temperature hydrothermal system. Based on its composition and on literature data on fluid inclusions, we have retrieved the P-T-X conditions of the deep hydrothermal system, aswell as its pH and fO2. The vapour feeding Nereidas would separate from a biphasic hydrothermal system characterized by the following parameters: t= 315 °C, P= 15 MPa, NaCl = 10 wt%, CO2=5 wt%, and similar proportion between liquid and vapour. Considering also the equilibria involving S-bearing gases and HCl, pH would approach the value of 1.5 while fO2 would correspond to the FeO-Fe2O3 buffer. Chlorine content is estimated at 10,300mg/l. Changes in the magmatic input into the hydrothermal system couldmodify its degree of vapourization and/or P-T-X conditions, thus inducing corresponding variations in vapour discharges and thermal waters. These findings, paralleled by contemporary measurements of water flow rates, could give significant clues on risk evaluation.
    Description: Published
    Description: 40-53
    Description: 2V. Struttura e sistema di alimentazione dei vulcani
    Description: JCR Journal
    Keywords: Nevado del Ruiz ; Water isotopes ; Geothermal system ; Equilibrium modelling ; Water chemistry ; 04.08. Volcanology ; 03.02. Hydrology
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Publication Date: 2021-03-02
    Description: Since hydrofracking is used for shale gas production, human caused seismicity have become a subject of increasing interest. Seismic monitoring is common for earthquakes generated by human operations like mining, reservoir impoundments, hydrocarbon and geothermal production, as well as reinjection of fluids. In Italy the Mw6.1 Reggio-Emilia earthquake of 20 May 2012 triggered particular interest in anthropogenic seismicity. It also raised the question of whether hydrocarbon exploitation induced variations in crustal stress that influenced the generation of these earthquakes. The Italian government commissioned a technical report compiling cases of documented and hypothesized anthropogenic seismicity. Following a governmental request, a technical report was compiled, describing the relation between anthropogenic activities and induced or triggered seismicity in Italy. This paper reviews these cases, on the basis of previously published works, and additional new analyses. Three cases of seismicity in Central Italy, occurring close to anthropogenic activities, are: (i) extraction of carbon dioxide (CO_2) from a borehole near Pieve Santo Stefano, (ii) the impoundment of the Montedoglio reservoir and (iii) geothermal energy production at Mt. Amiata. Since the sites are situated in the seismically active area of the Northern Apennines, we illustrate both by standard seismological analysis as well as by modeling to tackle the challenge of discriminating anthropogenic from natural seismicity.
    Description: Published
    Description: 80-94
    Description: 5T. Sismologia, geofisica e geologia per l'ingegneria sismica
    Description: JCR Journal
    Keywords: triggered/induced seismicity ; Italy ; CO2 extraction ; reservoir impoundment ; Mt. Amiata ; Upper Tiber Valley ; Solid Earth, Seismology
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Publication Date: 2021-03-19
    Description: Syneruptive gas flux time series can, in principle, be retrieved from satellite maps of SO2 collected during and immediately after volcanic eruptions, and used to gain insights into the volcanic processes which drive the volcanic activity. Determination of the age and height of volcanic plumes are key prerequisites for such calculations. However, these parameters are challenging to constrain using satellite-based techniques. Here, we use imagery from OMI and GOME-2 satellite sensors and a novel numerical procedure based on back-trajectory analysis to calculate plume height as a function of position at the satellite measurement time together with plume injection height and time at a volcanic vent location. We applied this new procedure to three Etna eruptions (12 August 2011, 18 March 2012 and 12 April 2013) and compared our results with independent satellite and ground-based estimations. We also compare our injection height time-series with measurements of volcanic tremor, which reflects the eruption intensity, showing a good match between these two datasets. Our results are a milestone in progressing towards reliable determination of gas flux data from satellite-derived SO2 maps during volcanic eruptions, which would be of great value for operational management of explosive eruptions.
    Description: 1) European Research Council under the European Union's Seventh Framework Programme (FP/2.007-2013)/ERC Grant Agreement no. 279802, project 283 CO2Volc. 2) MEDiterranean SUpersite Volcanoes 280 (MED-SUV) WP 3.3.3
    Description: Published
    Description: 79-91
    Description: 5V. Dinamica dei processi eruttivi e post-eruttivi
    Description: JCR Journal
    Keywords: Volcanic SO2 ; Trajectory modelling ; Remote sensing ; Volcanic tremor ; 04.08. Volcanology
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Publication Date: 2021-06-30
    Description: Volcanic activity exhibits a wide range of eruption styles, from relatively slow effusive eruptions that produce lava flows and lava domes, to explosive eruptions that can inject large volumes of fragmented magma and volcanic gases high into the atmosphere. Although controls on eruption style and scale are not fully understood, previous research suggests that the dynamics of magma ascent in the shallow subsurface (〈 10 km depth) may in part control the transition from effusive to explosive eruption and variations in eruption style and scale. Here we investigate the initial stages of explosive eruptions using a 1D transient model for magma ascent through a conduit based on the theory of the thermodynamically compatible systems. The model is novel in that it implements finite rates of volatile exsolution and velocity and pressure relaxation between the phases. We validate the model against a simple two-phase Riemann problem, the Air-Water Shock Tube problem, which contains strong shock and rarefaction waves. We then use the model to explore the role of the aforementioned finite rates in controlling eruption style and duration, within the context of two types of eruptions at the Soufrière Hills Volcano, Montserrat: Vulcanian and sub-Plinian eruptions. Exsolution, pressure, and velocity relaxation rates all appear to exert important controls on eruption duration. More significantly, however, a single finite exsolution rate characteristic of the Soufrière Hills magma composition is able to produce both end-member eruption durations observed in nature. The duration therefore appears to be largely controlled by the timescales available for exsolution, which depend on dynamic processes such as ascent rate and fragmentation wave speed.
    Description: Published
    Description: 110-139
    Description: 5V. Dinamica dei processi eruttivi e post-eruttivi
    Description: JCR Journal
    Keywords: Magma ascent ; Conduit dynamics ; Soufrière Hills Volcano ; Finite-rate exsolution ; Pressure relaxation ; Velocity relaxation ; 04.08. Volcanology ; Numerical modeling
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Publication Date: 2019-01-25
    Description: A combined approach merging stable isotopes and fatty acids was applied to study anthropogenic pollution in the Río Negro estuary. Fatty acid markers of vegetal detritus indicated considerable allochthonous inputs at freshwater sites. Correlative evidence of diatom fatty acids, δ13C, chlorophyll and particulate organic matter suggested the importance of diatoms for the autochthonous organic matter production at the river mouth. Low δ15N values (~0�) and high fatty acid 18:1(n-7) concentrations in the suspended particulate matter, in combination with the peaks of coliforms and ammonium, indicated a strong impact of untreated sewage discharge. The 15N depletion was related to oxygen-limited ammonification processes and incorporation of 15N depleted ammonium to microorganisms. This work demonstrates that the combined use of lipid and isotopic markers can greatly increase our understanding of biogeochemical factors and pollutants influencing estuaries, and our findings highlight the urgent need for water management actions to reduce eutrophication.
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , isiRev
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    facet.materialart.
    Unknown
    Alfred Wegener Institute for Polar and Marine Research & German Society of Polar Research
    In:  EPIC3Polarforschung, Bremerhaven, Alfred Wegener Institute for Polar and Marine Research & German Society of Polar Research, 88(1), pp. 1-6, ISSN: 00322490
    Publication Date: 2019-07-17
    Repository Name: EPIC Alfred Wegener Institut
    Type: "Polarforschung" , peerRev
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 11
    facet.materialart.
    Unknown
    Alfred Wegener Institute for Polar and Marine Research & German Society of Polar Research
    In:  EPIC3Polarforschung, Bremerhaven, Alfred Wegener Institute for Polar and Marine Research & German Society of Polar Research, 88(1), pp. 50-51, ISSN: 00322490
    Publication Date: 2019-07-17
    Repository Name: EPIC Alfred Wegener Institut
    Type: "Polarforschung" , peerRev
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 12
    facet.materialart.
    Unknown
    Alfred Wegener Institute for Polar and Marine Research & German Society of Polar Research
    In:  EPIC3Polarforschung, Bremerhaven, Alfred Wegener Institute for Polar and Marine Research & German Society of Polar Research, 88(1), pp. 52, ISSN: 00322490
    Publication Date: 2019-07-17
    Repository Name: EPIC Alfred Wegener Institut
    Type: "Polarforschung" , peerRev
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 13
    Publication Date: 2018-04-03
    Description: Harde (2017) proposes an alternative accounting scheme for the modern carbon cycle and concludes that only 4.3% of today's atmospheric CO2 is a result of anthropogenic emissions. As we will show, this alternative scheme is too simple, is based on invalid assumptions, and does not address many of the key processes involved in the global carbon cycle that are important on the timescale of interest. Harde (2017) therefore reaches an incorrect conclusion about the role of anthropogenic CO2 emissions. Harde (2017) tries to explain changes in atmospheric CO2 concentration with a single equation, while the most simple model of the carbon cycle must at minimum contain equations of at least two reservoirs (the atmosphere and the surface ocean), which are solved simultaneously. A single equation is fundamentally at odds with basic theory and observations. In the following we will (i) clarify the difference between CO2 atmospheric residence time and adjustment time, (ii) present recently published information about anthropogenic carbon, (iii) present details about the processes that are missing in Harde (2017), (iv) briefly discuss shortcoming in Harde's generalization to paleo timescales, (v) and comment on deficiencies in some of the literature cited in Harde (2017).
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , isiRev
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 14
    Publication Date: 2018-10-01
    Description: In paleoenvironmental studies, the mineralogical composition of sediments is an important indicator. In combination with other indicators, they contribute to the understanding of changes in sediment sourcing as well as in weathering and depositional processes. Fourier transforminfrared spectroscopy (FTIRS) spectra contain information on mineralogical composition because eachmineral has a unique absorption pattern in the mid-IR range. Although easily obtained, FTIR spectra are often too complex to infermineral concentrations directly. In this study, we use a calibration set of ca. 200 sediment samples conventionally measured using X-ray diffraction (XRD) in order to developmultivariate, partial least squares (PLS) regressionmodels relatingmineral contents to sediment spectra. Good correlations were obtained for the most common minerals (e.g. quartz, K-feldspar, illite, plagioclase, smectite, calcite). Correlation coefficients ranged from 0.85 to 0.92, coefficients for the validation varied from 0.64 to 0.80, the number of latent variables (PLS regression components) in the models ranged between 3 and 7 and the range of variation of the RMSEcv gradient was from 15.28 to 5.7.
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , isiRev
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 15
    facet.materialart.
    Unknown
    American Chemical Society
    In:  EPIC3Environmental Science & Technology, American Chemical Society, 52(22), pp. 13279-13288
    Publication Date: 2019-03-13
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , isiRev
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 16
    Publication Date: 2020-03-29
    Description: Most palaeo-deep-water reconstructions are based on geochemical information stored in the calcareous shells of Cibicidoides species but hardly anything is known about their life cycle, population dynamics or ecology. The number of specimens of a single Cibicidoides species can locally be very limited and species may be lacking completely during certain intervals in the geological past. As a consequence, geochemical analyses are often carried out on lumped Cibicidoides spp. assuming that they share the same epizoic to epifaunal habitat and precipitated their shell in comparable offsets to surrounding bottom water mass properties. However, there is a growing body of evidence that particularly Cibicidoides pachyderma and its morphotypes C. mundulus and C. kullenbergi, may not be reliable bottom water recorders. We have recently developed aquaria that allowed, for the first time, observations of Cibicidoides pachyderma var. C. mundulus under in situ pressure and temperature. Experiments were carried out with and without artificial sediments to simulate soft sediments and rocks, respectively. Seawater was set to pH 8 and pH 7.4 to simulate more or less particulate carbon export or more or less ventilation of bottom water. Our experiments demonstrate that C. mundulus may opt for an epifaunal or an infaunal habitat depending on elapsed time following physical disturbance, pH, current activity, the availability of sediments and growth. The specimen's initial response following transfer from atmospheric pressure into the high-pressure aquaria was to immerse into the sediment or to cover more or less parts of the test with aggregated sediments or algae. However, within 24 h a strong rheotaxis became apparent and most specimens moved to sites of increased current activity under normal pH conditions (pH 8). Only few specimens remained in algae cysts or in the sediment in the pH-8 experiment. On the contrary, all specimens under pH 7.4 agglutinated a firm sediment cyst around their test and remained infaunal throughout the experimental period of three months. Independent of pH, growth was only observed in specimens that lived within an agglutinated cyst or infaunal. A solid thick cyst covered the specimens of the pH 7.4 experiment throughout the experiment and possibly restricted water exchange between the in-cyst water and the surrounding artificial bottom water mass. We suggest that a more fragile and possibly more porous sedimentary envelope may, at least temporally, have covered the infaunal specimens under pH 8 but no evidence for this was found upon termination of the experiment.
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , peerRev
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 17
    facet.materialart.
    Unknown
    Elsevier
    In:  EPIC3Ecological MOdelling, Elsevier, 387, pp. 17-26
    Publication Date: 2020-01-21
    Description: Salpa thompsoni is an important grazer in the Southern Ocean. It is found from the Subtropical Convergence southward to the coastal Antarctic Seas but being most abundant in the Antarctic Polar Frontal Zone. Low temperatures appear to negatively affect their development, limiting their ability to occur in the krill dominated high Antarctic ecosystems. Yet reports indicate that with ocean warming S. thompsoni have experienced a southward shift in their distribution. As they are efficient filter feeders, this shift can result in large-scale changes in the Southern Ocean ecosystem by increasing competitive or predatory interactions with Antarctic krill. To explore salp bloom dynamics in the Southern Ocean a size-structured S. thompsoni population model was developed with growth, consumption, reproduction and mortality rates dependent on temperature and chlorophyll a conditions. The largest uncertainties in S. thompsoni population ecology are individual and population growth rates, with a recent study identifying the possibility that the life cycle could be much shorter than previously considered. Here we run a suite of hypothesis scenarios under various environmental conditions to determine the most appropriate growth rate. Temperature and chlorophyll a were sufficient drivers to recreate seasonal and interannual dynamics of salp populations at two locations. The most suitable growth model suggests that mean S. thompsoni growth rates are likely to be ∼1mm body length d−1, 2-fold higher than previous calculations. S. thompsoni biomass was dependent on bud release time, with larger biomass years corresponding to bud release occurring during favorable environmental conditions; increasing the survival and growth of blastozooids and resulting in higher embryo release. This model confirms that it is necessary for growth and reproductive rates to be flexible in order for the salp population to adapt to varying environmental conditions and provides a framework that can examine how future salp populations might respond to climate change.
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , peerRev
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 18
    facet.materialart.
    Unknown
    Elsevier
    In:  EPIC3Encyclopedia of the Anthropocene, Encyclopedia of the Anthropocene, Elsevier, 3, pp. 217-228
    Publication Date: 2020-02-09
    Description: Human influence on the climate system, through greenhouse gas emissions, is clear and climate warming unequivocal. Recent climate change has had widespread impacts on natural systems including shifts in the ranges (distributions) of land, freshwater, and marine organisms. Effects of these biogeographical shifts transcend single-species to impact on ecosystem goods and services resulting in significant social and economic costs to human communities. In this article we provide a general overview of these factors by reviewing current evidence from terrestrial, freshwater, and marine ecosystems.
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , peerRev
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 19
    Publication Date: 2018-02-26
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , isiRev
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 20
    Publication Date: 2018-06-05
    Description: Fossil carbonate skeletons of marine organisms are archives for understanding the development and evolution of palaeo-environments. However, the correct assessment of past environment dynamics is only possible when pristine skeletons and their biogenic characteristics are unequivocally distinguishable from diagenetically-alteredskeletal elements and non-biogenic features. In this study, we extend our work on diagenesis of biogenic aragonite (Casella et al. 2017) to the investigation of biogenic low-Mg calcite using brachiopod shells. We examined and compared microstructural characteristics inducedby laboratory-based alteration to structural features derived from diagenetic alteration in natural environments. We used four screening methods: cathodoluminescence (CL), cryogenic and conventional field emission-scanning electronmicroscopy (FE-SEM), atomic force microscopy (AFM) and electron backscatter diffraction (EBSD).We base our assessments of diagenetic alteration and overprint on measurements of, a) images of optical overprint signals, b) changes in calcite crystal orientation patterns, and c) crystal co-orientation statistics. According to the screening process, altered and overprinted samples define two groups. In Group 1 the entire shell is diagenetically overprinted, whereas in Group 2 the shell contains pristine as well as overprinted parts. In the case of Group 2 shells, alteration occurred either along the periphery of the shell including the primary layer or at the interior-facing surface of the fibrous/columnar layer. In addition, we observed an important mode of the overprinting process, namely the migration of diagenetic fluids through the endopunctae corroborated by mineral formation and overprinting in their immediate vicinity, while leaving shell parts between endopunctae in pristine condition. Luminescence (CL) and microstructural imaging (FE-SEM) screening give first-order observations of the degree of overprint as they cover macro-to micron scale alteration features. For a comprehensive assessment of diagenetic overprint these screening methods should be complemented by screening techniques such as EBSD and AFM. They visualise diagenetic changes at submicron and nanoscale levels depicting the replacement of pristine nanocomposite mesocrystal biocarbonate (NMB) by inorganic rhombohedral calcite (IRC). The integration of screening methods allows for the unequivocal identification of highly-detailed alteration features as well as an assessment of the degree of diagenetic alteration.
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , isiRev
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 21
    Publication Date: 2018-12-05
    Description: We study the basement configuration in the slow-spreading Eurasia Basin, Arctic Ocean. Two multichannel seismic (MCS) profiles, which we acquired during ice-free conditions with a 3600 m long streamer, image the transition from the North Barents Sea Margin into the southern Eurasia Basin. The seismic lines resolve the up to 5000 m thick sedimentary section, as well as the crustal architecture of the southern Eurasia Basin along 120 km and 170 km, respectively. The seismic data show large faulted and rotated basement blocks. Gravity modeling indicates a thin basement with a thickness of 1–3 km and a density of 2.8*103 kg/m3 between the base of the sediments and the top of the mantle, which indicates exhumed and serpentinized mantle. The Gakkel spreading ridge, located in northern prolongation of the seismic lines is characterized by an amagmatic or sparsely magmatic segment. From the structural similarity between the basement close to the ultra-slow spreading ridge and our study area, we conclude that the basement in the Eurasia Basin is predominantly formed by exhumed and serpentinized mantle, with magmatic additions. An initial strike-slip movement of the Lomonosov Ridge along the North Barents Sea Margin and subsequent near-orthogonal opening of the Nansen Basin is supposed to have brought mantle material to the surface, which was serpentinized during this process. Continuous spreading thinned the serpentinized mantle and subsequent normal faulting produced distinct basement blocks. We propose that mantle exhumation has likely been active since the opening of the Eurasia Basin.
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , isiRev
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 22
    facet.materialart.
    Unknown
    American Chemical Society
    In:  EPIC3Crystal Growth & Design, American Chemical Society, 18, pp. 2563-2571
    Publication Date: 2018-04-23
    Description: The morphology and growth kinetics of ice single crystals in aqueous solutions of type III antifreeze protein (AFP-III) have been studied in detail over a range of AFP-III concentrations and supercoolings. In pure water, the shape of ice crystals changes from the circular disklike to planar dendritic with increasing supercooling. In AFP-III solutions, ice crystals in the form of faceted plates, irregular dendrites with polygonized tips, and needles appear with increasing supercooling and AFP-III concentration. The growth rate of ice crystals in the crystallographic a direction is 2 orders of magnitude higher than that in the c direction. AFP-III molecules cause the stoppage of the growth of the prismatic and basal faces at low supercoolings. When supercooling exceeds the critical value, AFP-III favors the acceleration of the growth in both a and c directions. The observed behavior of AFP-III is explained in terms of the Cabrera-Vermilyea pinning model and the specificity of the dissipation of latent heat from the growing crystals with different shapes.
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , isiRev
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 23
    facet.materialart.
    Unknown
    Elsevier
    In:  EPIC3Deep Sea Research Part II: Topical Studies in Oceanography, Elsevier, 149, pp. 25-30, ISSN: 09670645
    Publication Date: 2018-06-19
    Description: The deep basins of the Bransfield Strait (BS) are ventilated by Weddell Sea (WS) waters from different origins. Depending on the source and density, these water masses follow different routes across the complex topography near the tip of the Antarctic Peninsula and thus into the Bransfield Strait abyss. Using a global setup of the Finite Element Sea-ice Ocean Model (FESOM) we show that the WS waters found at the western WS continental shelf break have a higher influence on the short period variability of BS bottom waters than the waters present over the continental shelf. Adding passive tracers to the glacial melt water (GMW) from two different origins, Larsen Ice Shelf (LIS) and Filchner-Ronne Ice Shelf (FRIS), we show that the GMW from FRIS has a larger influence on BS bottom waters than the GMW from LIS. FRIS GMW has a higher concentration in the BS eastern basin, while LIS GMW is more abundant in the BS central basin. This duality mainly leads to the difference between BS central and eastern basins seen on the observations. This is a novel result and we believe is a significant contribution to the understanding of the BS-WS circulation and interactions.
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , peerRev
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 24
    Publication Date: 2018-09-04
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , isiRev
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 25
    Publication Date: 2018-03-08
    Description: Which are the trends that are transforming research management and how do research organizations respond to these changes? What are the available services to support research during EC projects’ life-cycles? Are there research information systems in use and to which extent are they integrated? The paper is structured as follows: a survey conducted over a sample of universities and research centers in Italy is presented in section 2. Section 3 describes significant case studies. Section 4 illustrates mobility figures and trends in EU funded projects. Section 5 concludes with considerations about trends and suggestions for improvement.
    Description: Published
    Description: 309-314
    Description: 7TM. Sviluppo e Trasferimento Tecnologico
    Description: N/A or not JCR
    Keywords: Research support services ; CRIS ; research information management ; Human Resources Strategy for Researchers
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 26
    Publication Date: 2018-03-26
    Description: At Vulcano (Aeolian Islands, Italy), different measurement methods have been developed for more than 30 years and models were formulated to account for the real time evolution of the actual solphataric activity. The results of a long term monitoring of surface temperature and of CO2 flux from soil, reviewed in a multidisciplinary framework, are presented here. These two parameters, monitored at the ground surface, highlighted local variations of the hydrothermal release and the time series of data showed in several instances, different range of values. The background and anomalous ranges defined by this long term monitoring are robust by a statistical point of view. The long term data-series offered a useful tool to verify conceptual framework and to better define the natural hazard evaluation integrating “classical” and “new” investigation techniques. Moreover, La Fossa area lays in a geodynamic context with active seismo- tectonic processes, frequently perturbing the pressure field of the hydrothermal system under investigation. Any perturbation in the pressure state variable (P) of the system, results in an excited state of its components and a relevant transfer of energy and mass towards the surface starts to counterbalance the perturbation. The continuous monitoring of surface temperature reveals the effects of the forces guiding the heat flows whereas the space variation of temperature indicates the rising paths of hydrothermal and magmatic fluids. The occurrence of new fumaroles and mofetes, or even changing emission rates of fluids by these vents, rises questions about the evolution of the equilibrium state of buried hydrothermal system, or about changing physical condition of overburden rocks. The conceptual framework suggesting the potential of our time series of field data is that a rock body, can be seen as a multiphase geochemical system where the fluid phases play a crucial role in defining the physical changes of the body and its response to the different forces acting on it. The changes of pore pressure depend on the balance between gas phases production and gas leaked out from a geochemical system. Analyses of fluxes at the system boundaries can give information on the equilibrium of the interacting geospheres. Even if playing variables are too many, some specific compounds and parameters can be selected as indicators of the state of the system.#
    Description: Published
    Description: Yokohama, Japan
    Description: 4V. Dinamica dei processi pre-eruttivi
    Keywords: Long term monitoring ; Vulcano ; Fluid geochemistry
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: Conference paper
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 27
    Publication Date: 2018-03-02
    Description: The action of using someone else’s production, ideas, or research without acknowledging the source and then claiming credit for them is known as plagiarism. Plagiarism is in principle a moral offense; it is not always an illegal action but certainly is an ethical complex case. Copying without permission or stealing someone else’s work violates the standard codes of scholarly conduct and ethical behavior in professional scientific research. Science may be somewhat more prone to plagiarism in that scholars exchange ideas and proposals more frequently than artists, for example. Workshops, scientific meetings, and round tables are places where primitive and preliminary researches are presented and discussed before their official presentation. This chapter discusses plagiarism and self plagiarism and tries to point out the role of the scientific community toward this kind of scientific misconduct.
    Description: Published
    Description: 5TM. Informazione ed editoria
    Keywords: Copyright infringement, Ethical conduct, Plagiarism. ; 05.03. Educational, History of Science, Public Issues
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: book chapter
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 28
    Publication Date: 2018-02-16
    Description: Among the considerable number of studies that can be carried out using muons, we pay specific attention to the radiography of volcanoes based on the same principle of the X-ray radiography of human body. Thanks to their high penetration capability, cosmic-ray muons can be used to reconstruct the density distribution of the interior of huge structures by measuring the attenuation induced by the material on the muon flux. In particular, the quantitative understanding of the inner structure of volcanoes is a key-point to forecast the dangerous stages of activity and mitigate volcanic hazards. The instrumental approach is currently based on the detection of muons crossing hodoscopes made up of scintillator planes. Unfortunately, these detectors are affected by a strong background comprised by accidental coincidence of vertical shower particles, horizontal high-energy electrons and upward going particles. We propose an alternative technique based on the detection of the Cherenkov light produced by muons. This can be achieved with an imaging atmospheric Cherenkov telescope composed of a high reflectivity optical system that focus the Cherenkov light onto a multi-pixel focal camera with fast read-out electronics. The Cherenkov light emitted by a muon is imaged on the camera as an annular pattern which contains information to reconstruct the direction of the incident muon. We have estimated that using the Cherenkov imaging technique for muon radiography of volcanoes gives the advantage of a negligible background and improved spatial resolution, compared to the majority of the particle detectors. We present results of simulations based on a telescope with a positioning resolution of 13.5 m which corresponds to an acceptance of 9 cm2 sr. The telescope is located 1500 m far from a toy-model volcano, namely, a cone with a base diameter of 500 m and a height of 240 m. We test the feasibility of the proposed method by estimating the minimum number of observation nights needed to resolve inner empty conduits of different diameter.
    Description: Published
    Description: 122–125
    Description: 2V. Struttura e sistema di alimentazione dei vulcani
    Description: N/A or not JCR
    Keywords: Imaging Atmospheric Cherenkov Telescope ; Volcano radiography ; Muons, ; Volcano monitoring ; Mount Etna
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 29
    Publication Date: 2018-03-26
    Description: We present soil temperature data from a peripheral fumarole emission of Mt Etna at the top end of a radial fracture called Bottoniera. This area lies in the northern flank of the volcano (2,500m a.s.l.), and was interested by fissure eruption during 2002/2003. In the steam heated soil lying around the fumarole release, a shallow vertical profile has been monitored from October 2009 to September 2012. We estimated the local surface heat flux and compared its time variations to the eruptive activity occurred during the monitoring period. The eruptive vents were located on the opposite flank, (〉3200m a.s.l.), far about 4km. The heat flux from this peripheral emission has been highly influenced by the eruptive activity. Its time variations are correlated to the variable rates of products emitted from January 2011 to April 2012. Different ranges of heat flux values have been associated to the pre-eruptive phase, to the productive eruption period and to the end of this eruptive cycle. The decrease of heat flux was registered before the end of the eruptive cycle. The continuous thermal monitoring revealed in real time that ascending magma through the active conduits is the heating bottom source of the heat flux dispersed by a complex network of active fractures present in this area. The recorded data suggest the steam heated soil around fumaroles vents as a possible new investigation field for a low cost monitoring of the local variation in the structural weakness of the apparatus. Extending this thermal monitoring to the other steaming grounds of this complex volcanic system we could also follow variations of the fluid circulation paths and obtain direct information about local pore pressure changes. A multivariate analysis of recorded data could suggest, which part of this complex apparatus is being involved, time by time, with the ongoing evolution. It would contribute to the evaluation of flank instability caused by physical changes occurring on the network of active fractures, and inferred by multidisciplinary investigations (such as deformation patterns, tectonic lineaments and geochemical features of underground waters and diffuse gas emissions).
    Description: Published
    Description: Yokohama, Japan
    Description: 4V. Dinamica dei processi pre-eruttivi
    Description: 5V. Dinamica dei processi eruttivi e post-eruttivi
    Keywords: Fumaroles ; Steam heated Soil ; Thermal monitoring ; Eruptive cycle ; Fluid geochemistry
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: Conference paper
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 30
    Publication Date: 2019-03-26
    Description: The examples of geochemical monitoring results provided in this review article show the close relationships among data analysis, interpretation, and modeling. We particularly focus on describing the fieldwork procedures, since any theoretical approach must always be verified and supported by field data, rather than just by experiments controlled in laboratory.
    Description: Fluids discharged from volcanic systems are the direct surface manifestation of magma degassing at depth and provide primary insights for evaluating the state of volcanic activity. We review the geochemical best practice in volcanic surveillance based to a huge amount of monitoring data collected at different active volcanoes using both continuous and discontinuous approaches. The targeted volcanoes belong to the Aeolian Arc located in the Tyrrhenian Sea (Italy), and they have exhibited different activity states during the monitoring activities reported here. La Fossa cone on Vulcano Island has been in an uninterrupted quiescent stage characterized by variable solfataric activity. In contrast, Stromboli Island has shown a persistent mild explosive activity, episodically interrupted by effusive eruptions (in 1985, 2002, 2007, and 2014). Panarea Island, which is the summit of a seamount rising from the seafloor of the southern Tyrrhenian Sea, showed only undersea fluid release. The only observable clues of active volcanism at Panarea Island have been impulsive changes in the undersea fluid release, with the last submarine gas burst event being observed in November 2002. The geochemical monitoring and observations at each of these volcanoes has directly involved the volcanic plume and/or the fumarole vents, thermal waters, and diffuse soil degassing, depending on the type of manifestations and the level of activity encountered. Through direct access to the magmatic samples (when possible) and the collection of as much observable data related to the fluid release as possible, the aim has been (i) to verify the thermodynamic equilibrium condition, (ii) to discern among the possible hydrothermal, magmatic, marine, and meteoric sources in the fluid mixtures, (iii) to develop models of the fluid circulation supported by data, (iv) to follow the evolution of these natural systems by long-term monitoring, and (v) to support surveillance actions related to defining the volcanic risk and the evaluation and possible mitigation of related hazards. The examples provided in this review article show the close relationships among data analysis, interpretation, and modeling. We particularly focus on describing the fieldwork procedures, since any theoretical approach must always be verified and supported by field data, rather than just by experiments controlled in laboratory. Indeed the natural systems involve many variables producing effects that cannot be neglected. The monitored volcanic systems have been regarded as natural laboratories, and all of the activities have focused on both volcanological research and surveillance purposes in order to ensure that these two goals have overlapped. An appendix is also included that explains the scientific approach to the systematic activities, regarding geochemical monitoring of volcanic activity.
    Description: Published
    Description: 241-276
    Description: 4V. Processi pre-eruttivi
    Description: JCR Journal
    Keywords: geochemical methodologies ; Vulcano ; Stromboli ; Panarea ; Geochemical Monitoring
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 31
    facet.materialart.
    Unknown
    Alfred Wegener Institute for Polar and Marine Research & German Society of Polar Research
    In:  EPIC3Polarforschung, Bremerhaven, Alfred Wegener Institute for Polar and Marine Research & German Society of Polar Research, 88(1), pp. 49, ISSN: 00322490
    Publication Date: 2019-07-17
    Repository Name: EPIC Alfred Wegener Institut
    Type: "Polarforschung" , peerRev
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 32
    facet.materialart.
    Unknown
    Alfred Wegener Institute for Polar and Marine Research & German Society of Polar Research
    In:  EPIC3Polarforschung, Bremerhaven, Alfred Wegener Institute for Polar and Marine Research & German Society of Polar Research, 88(1), pp. 23-30, ISSN: 00322490
    Publication Date: 2019-07-17
    Repository Name: EPIC Alfred Wegener Institut
    Type: "Polarforschung" , peerRev
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 33
    facet.materialart.
    Unknown
    Alfred Wegener Institute for Polar and Marine Research & German Society of Polar Research
    In:  EPIC3Polarforschung, Bremerhaven, Alfred Wegener Institute for Polar and Marine Research & German Society of Polar Research, 88(1), pp. 53-54, ISSN: 00322490
    Publication Date: 2019-07-17
    Repository Name: EPIC Alfred Wegener Institut
    Type: "Polarforschung" , peerRev
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 34
    facet.materialart.
    Unknown
    Alfred Wegener Institute for Polar and Marine Research & German Society of Polar Research
    In:  EPIC3Polarforschung, Bremerhaven, Alfred Wegener Institute for Polar and Marine Research & German Society of Polar Research, 88(1), pp. 55, ISSN: 00322490
    Publication Date: 2019-07-17
    Repository Name: EPIC Alfred Wegener Institut
    Type: "Polarforschung" , peerRev
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 35
    facet.materialart.
    Unknown
    Alfred Wegener Institute for Polar and Marine Research & German Society of Polar Research
    In:  EPIC3Polarforschung, Bremerhaven, Alfred Wegener Institute for Polar and Marine Research & German Society of Polar Research, 88(1), pp. 57-61, ISSN: 00322490
    Publication Date: 2019-07-17
    Repository Name: EPIC Alfred Wegener Institut
    Type: "Polarforschung" , peerRev
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 36
    facet.materialart.
    Unknown
    Alfred Wegener Institute for Polar and Marine Research & German Society of Polar Research
    In:  EPIC3Polarforschung, Bremerhaven, Alfred Wegener Institute for Polar and Marine Research & German Society of Polar Research, 88(1), pp. 56, ISSN: 00322490
    Publication Date: 2019-07-17
    Repository Name: EPIC Alfred Wegener Institut
    Type: "Polarforschung" , peerRev
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 37
    facet.materialart.
    Unknown
    Alfred Wegener Institute for Polar and Marine Research & German Society of Polar Research
    In:  EPIC3Polarforschung, Bremerhaven, Alfred Wegener Institute for Polar and Marine Research & German Society of Polar Research, 88(1), pp. 62, ISSN: 00322490
    Publication Date: 2019-07-17
    Repository Name: EPIC Alfred Wegener Institut
    Type: "Polarforschung" , peerRev
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 38
    facet.materialart.
    Unknown
    Alfred Wegener Institute for Polar and Marine Research & German Society of Polar Research
    In:  EPIC3Polarforschung, Bremerhaven, Alfred Wegener Institute for Polar and Marine Research & German Society of Polar Research, 88(1), pp. 31-48, ISSN: 00322490
    Publication Date: 2019-07-17
    Repository Name: EPIC Alfred Wegener Institut
    Type: "Polarforschung" , peerRev
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 39
    facet.materialart.
    Unknown
    Alfred Wegener Institute for Polar and Marine Research & German Society of Polar Research
    In:  EPIC3Polarforschung, Bremerhaven, Alfred Wegener Institute for Polar and Marine Research & German Society of Polar Research, 88(1), pp. 7-21, ISSN: 00322490
    Publication Date: 2019-07-17
    Repository Name: EPIC Alfred Wegener Institut
    Type: "Polarforschung" , peerRev
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 40
    Publication Date: 2022-05-25
    Description: © The Author(s), 2017. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Regional Studies in Marine Science 18 (2018): 1-10, doi:10.1016/j.rsma.2017.12.004.
    Description: The variations of temperature and salinity in the Sudanese coastal zone of the Red Sea are studied for the first time using measurements acquired from survey cruises during 2009–2013 and from a mooring during 2014–2015. The measurements show that temperature and salinity variability above the permanent pycnocline is dominated by seasonal signals, similar in character to seasonal temperature and salinity oscillations observed further north on the eastern side of the Red Sea. Using estimates of heat flux, circulation and horizontal temperature/salinity gradients derived from a number of sources, we determined that the observed seasonal signals of temperature and salinity are not the product of local heat and mass flux alone, but are also due to alongshore advection of waters with spatially varying temperature and salinity. As the temperature and salinity gradients, characterized by warmer and less saline water to the south, exhibit little seasonal variation, the seasonal salinity and temperature variations are closely linked to an observed seasonal oscillation in the along-shore flow, which also has a mean northward component. We find that the inclusion of the advection terms in the heat and mass balance has two principal effects on the computed temperature and salinity series. One is that the steady influx of warmer and less saline water from the south counteracts the long-term trend of declining temperatures and rising salinities computed with only the local surface flux terms, and produces a long-term steady state in temperature and salinity. The second effect is produced by the seasonal alongshore velocity oscillation and most profoundly affects the computed salinity, which shows no seasonal signal without the inclusion of the advective term. In both the observations and computed results, the seasonal salinity signal lags that of temperature by roughly 3 months.
    Description: The SPS surveys were funded by the Norwegian Norad’s Program for Master Studies and organized by IMR–RSU in Port Sudan. The central Red Sea mooring data were acquired as part of a WHOI–KAUST collaboration funded by Award Nos. USA00001, USA00002, and KSA00011 to the WHOI by the KAUST in the Kingdom of Saudi Arabia. The work of I. Skjelvan and A.M. Omar was partly supported by the Research Council of Norway through the MIMT Center for Research-based Innovation. This work is part of a Ph.D. project at GFI–UiB funded by the Norwegian Quota program .
    Keywords: Coastal Red Sea ; Temperature ; Salinity ; Time series ; Seasonality ; Alongshore advection
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 41
    Publication Date: 2022-05-25
    Description: © The Author(s), 2018. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Quaternary Science Reviews 185 (2018): 135-152, doi:10.1016/j.quascirev.2018.02.012.
    Description: The largest coherent cold-water coral (CWC) mound province in the Atlantic Ocean exists along the Mauritanian margin, where up to 100 m high mounds extend over a distance of ∼400 km, arranged in two slope-parallel chains in 400–550 m water depth. Additionally, CWCs are present in the numerous submarine canyons with isolated coral mounds being developed on some canyon flanks. Seventy-seven Uranium-series coral ages were assessed to elucidate the timing of CWC colonisation and coral mound development along the Mauritanian margin for the last ∼120,000 years. Our results show that CWCs were present on the mounds during the Last Interglacial, though in low numbers corresponding to coral mound aggradation rates of 16 cm kyr−1. Most prolific periods for CWC growth are identified for the last glacial and deglaciation, resulting in enhanced mound aggradation (〉1000 cm kyr−1), before mound formation stagnated along the entire margin with the onset of the Holocene. Until today, the Mauritanian mounds are in a dormant state with only scarce CWC growth. In the canyons, live CWCs are abundant since the Late Holocene at least. Thus, the canyons may serve as a refuge to CWCs potentially enabling the observed modest re-colonisation pulse on the mounds along the open slope. The timing and rate of the pre-Holocene coral mound aggradation, and the cessation of mound formation varied between the individual mounds, which was likely the consequence of vertical/lateral changes in water mass structure that placed the mounds near or out of oxygen-depleted waters, respectively.
    Description: This study received funding from and contributes to the DFG-projects "Palaeo-WACOM" (HE 3412/17-1) and "Cold-water coral mound development in a tropical upwelling cell – the great wall of(f) Mauritania" (Ti 706/3-1). A. Freiwald received funding from the Hessian initiative for the development of scientific and economic excellence (LOEWE) at the Biodiversity and Climate Research Centre (BiK-F), Frankfurt, Germany.
    Keywords: Lophelia pertusa ; Coral mound ; Submarine canyon ; Uranium-series dating ; Mound aggradation rate ; Last glacial ; Dissolved oxygen concentration ; South Atlantic Central Water ; Mauritanian margin
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 42
    Publication Date: 2022-05-25
    Description: © The Author(s), 2018. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Remote Sensing of Environment 217 (2018): 126-143, doi:10.1016/j.rse.2018.08.010.
    Description: Diatoms dominate global silica production and export production in the ocean; they form the base of productive food webs and fisheries. Thus, a remote sensing algorithm to identify diatoms has great potential to describe ecological and biogeochemical trends and fluctuations in the surface ocean. Despite the importance of detecting diatoms from remote sensing and the demand for reliable methods of diatom identification, there has not been a systematic evaluation of algorithms that are being applied to this end. The efficacy of these models remains difficult to constrain in part due to limited datasets for validation. In this study, we test a bio-optical algorithm developed by Sathyendranath et al. (2004) to identify diatom dominance from the relationship between ratios of remote sensing reflectance and chlorophyll concentration. We evaluate and refine the original model with data collected at the Martha's Vineyard Coastal Observatory (MVCO), a near-shore location on the New England shelf. We then validated the refined model with data collected in Harpswell Sound, Maine, a site with greater optical complexity than MVCO. At both sites, despite relatively large changes in diatom fraction (0.8–82% of chlorophyll concentration), the magnitude of variability in optical properties due to the dominance or non-dominance of diatoms is less than the variability induced by other absorbing and scattering constituents of the water. While the original model performance was improved through successive re-parameterizations and re-formulations of the absorption and backscattering coefficients, we show that even a model originally parameterized for the Northwest Atlantic and re-parameterized for sites such as MVCO and Harpswell Sound performs poorly in discriminating diatom-dominance from optical properties.
    Description: This work was supported by: a Woods Hole Oceanographic Institution Summer Student Fellowship (NSF REU award #1156952) and a Bowdoin College Grua/O'Connell Research Award to SJK; grants to HMS from NASA (Ocean Biology and Biogeochemistry program and Biodiversity and Ecological Forecasting program), NSF (Ocean Sciences), the Gordon and Betty Moore Foundation, the Simons Foundation, and NOAA through the Cooperative Institute for the North Atlantic Region (CINAR) under Cooperative Agreement NA14OAR4320158; and grants to CSR from NASA (Ocean Biology and Biogeochemistry program).
    Keywords: Phytoplankton ; Community structure ; Ocean color ; Diatoms
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 43
    Publication Date: 2022-05-25
    Description: © The Author(s), 2018. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Regional Studies in Marine Science 24 (2018): 336-342, doi:10.1016/j.rsma.2018.09.006.
    Description: The variations of sea level over the Red Sea may be divided into three broad categories: tidal, seasonal and weather-band. Our study employs a variety of in situ and satellite-derived data in the first comprehensive examination of the Red Sea water level variations in the weather-band (covering periods of 4–30 days). In the central Red Sea, the range of the weather-band sea level signal is of order 0.7 m, which exceeds the tidal and seasonal sea level ranges. From EOF and correlation analysis, we find that a large fraction of the weather-band sea level variation is due to a single mode of motion that extends over the entire Red Sea. In this mode, the water level rises and falls in unison with an amplitude that declines going southward over the southern Red Sea. The temporal signal of this mode is highly correlated with the along-axis surface wind stress over the southern Red Sea, and is closely reproduced by a simple one-dimensional barotropic model with forcing by the along-axis wind stress. Although this model does not account for the full suite of dynamics affecting weather-band sea level variations in the Red Sea, it may serve as a useful predictive tool. Sea level changes associated with the development and movement of sub-mesoscale features (e.g., eddies and boundary currents) are also shown to contribute to weather-band sea level motions in the Red Sea.
    Description: The pressure sensor and meteorological buoy data were acquired as part of a program supported by Award Nos. USA00001, USA00002 and KSA00011 made by KAUST to WHOI. The data analysis and modeling work of this study were supported General Commission for Survey (GCS), under a project number RGC/3/1612-01-01 made by Office of Sponsored research (ORS)/KAUST, Kingdom of Saudi Arabia.
    Keywords: Red Sea water levels ; Wind-driven sea level variations
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 44
    Publication Date: 2022-05-25
    Description: This paper is not subject to U.S. copyright. The definitive version was published in Global and Planetary Change 167 (2018): 1-23, doi:10.1016/j.gloplacha.2018.04.004.
    Description: A compilation of foraminiferal stable isotope measurements from southern high latitude (SHL) deep-sea sites provides a novel perspective important for understanding Earth's paleotemperature and paleoceanographic changes across the rise and fall of the Cretaceous Hot Greenhouse climate and the subsequent Paleogene climatic optimum. Both new and previously published results are placed within an improved chronostratigraphic framework for southern South Atlantic and southern Indian Ocean sites. Sites studied were located between 58° and 65°S paleolatitude and were deposited at middle to upper bathyal paleodepths. Oxygen isotope records suggest similar trends in both bottom and surface water temperatures in the southern sectors of the South Atlantic and in the Indian Ocean basins. Warm conditions were present throughout the Albian, extreme warmth existed during the Cretaceous Thermal Maximum (early-mid-Turonian) through late Santonian, and long-term cooling began in the Campanian and culminated in Cretaceous temperature minima during the Maastrichtian. Gradients between surface and seafloor δ18O and δ13C values were unusually high throughout the 11.5 m.y. of extreme warmth during the Turonian-early Campanian, but these vertical gradients nearly disappeared by the early Maastrichtian. In absolute terms, paleotemperature estimates that use standard assumptions for pre-glacial seawater suggest sub-Antarctic bottom waters were ≥21 °C and sub-Antarctic surface waters were ≥27 °C during the Turonian, values warmer than published climate models support. Alternatively, estimated temperatures can be reduced to the upper limits of model results through freshening of high latitude waters but only if there were enhanced precipitation of water with quite low δ18O values. Regardless, Turonian planktonic δ18O values are ~1.5‰ lower than minimum values reported for the Paleocene-Eocene Thermal Maximum (PETM) from the same region, a difference which corresponds to Turonian surface temperatures ~6 °C warmer than peak PETM temperatures if Turonian and Paleocene temperatures are estimated using the same assumptions. It is likely that warm oceans surrounding and penetrating interior Antarctica (given higher relative sea level) prevented growth of Antarctic ice sheets at all but the highest elevations from the late Aptian through late Campanian; however, Maastrichtian temperatures may have been cool enough to allow growth of small, ephemeral ice sheets. The standard explanation for the sustained warmth during Cretaceous Hot Greenhouse climate invokes higher atmospheric CO2 levels from volcanic outgassing, but correlation among temperature estimates, proxy estimates of pCO2, and intervals of high fluxes of both mafic and silicic volcanism are mostly poor. This comparison demonstrates that the relative timing between events and their putative consequences need to be better constrained to test and more fully understand relationships among volcanism, pCO2, temperature ocean circulation, Earth's biota and the carbon cycle.
    Description: Funding from the Smithsonian National Museum of Natural History and the National Science Foundation (NSF-OCE 1261586) helped support this research.
    Keywords: Cretaceous Hot Greenhouse ; Foraminiferal stable isotopes ; Volcanic outgassing ; pCO2 proxies ; Greenhouse glacier hypothesis ; Southern high latitudes
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 45
    Publication Date: 2022-05-25
    Description: © The Author(s), 2018. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Chemical Geology 493 (2018): 210-223, doi:10.1016/j.chemgeo.2018.05.040.
    Description: The GEOTRACES Intermediate Data Product 2017 (IDP2017) is the second publicly available data product of the international GEOTRACES programme, and contains data measured and quality controlled before the end of 2016. The IDP2017 includes data from the Atlantic, Pacific, Arctic, Southern and Indian oceans, with about twice the data volume of the previous IDP2014. For the first time, the IDP2017 contains data for a large suite of biogeochemical parameters as well as aerosol and rain data characterising atmospheric trace element and isotope (TEI) sources. The TEI data in the IDP2017 are quality controlled by careful assessment of intercalibration results and multi-laboratory data comparisons at crossover stations. The IDP2017 consists of two parts: (1) a compilation of digital data for more than 450 TEIs as well as standard hydrographic parameters, and (2) the eGEOTRACES Electronic Atlas providing an on-line atlas that includes more than 590 section plots and 130 animated 3D scenes. The digital data are provided in several formats, including ASCII, Excel spreadsheet, netCDF, and Ocean Data View collection. Users can download the full data packages or make their own custom selections with a new on-line data extraction service. In addition to the actual data values, the IDP2017 also contains data quality flags and 1-σ data error values where available. Quality flags and error values are useful for data filtering and for statistical analysis. Metadata about data originators, analytical methods and original publications related to the data are linked in an easily accessible way. The eGEOTRACES Electronic Atlas is the visual representation of the IDP2017 as section plots and rotating 3D scenes. The basin-wide 3D scenes combine data from many cruises and provide quick overviews of large-scale tracer distributions. These 3D scenes provide geographical and bathymetric context that is crucial for the interpretation and assessment of tracer plumes near ocean margins or along ridges. The IDP2017 is the result of a truly international effort involving 326 researchers from 25 countries. This publication provides the critical reference for unpublished data, as well as for studies that make use of a large cross-section of data from the IDP2017. This article is part of a special issue entitled: Conway GEOTRACES - edited by Tim M. Conway, Tristan Horner, Yves Plancherel, and Aridane G. González.
    Description: We gratefully acknowledge financial support by the Scientific Committee on Oceanic Research (SCOR) through grants from the U.S. National Science Foundation, including grants OCE-0608600, OCE-0938349, OCE-1243377, and OCE-1546580. Financial support was also provided by the UK Natural Environment Research Council (NERC), the Ministry of Earth Science of India, the Centre National de Recherche Scientifique, l'Université Paul Sabatier de Toulouse, the Observatoire Midi-Pyrénées Toulouse, the Universitat Autònoma de Barcelona, the Kiel Excellence Cluster The Future Ocean, the Swedish Museum of Natural History, The University of Tokyo, The University of British Columbia, The Royal Netherlands Institute for Sea Research, the GEOMAR-Helmholtz Centre for Ocean Research Kiel, and the Alfred Wegener Institute.
    Keywords: GEOTRACES ; Trace elements ; Isotopes ; Electronic atlas ; IDP2017
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 46
    Publication Date: 2022-05-25
    Description: Author Posting. © American Chemical Society, 2018. This is an open access article published under an ACS AuthorChoice License. The definitive version was published in Environmental Science and Technology Letters 5 (2018): 226–231, doi:10.1021/acs.estlett.8b00084.
    Description: Chemical dispersants are one of many tools used to mitigate the overall environmental impact of oil spills. In principle, dispersants break up floating oil into small droplets that disperse into the water column where they are subject to multiple fate and transport processes. The effectiveness of dispersants typically decreases as oil weathers in the environment. This decrease in effectiveness is often attributed to evaporation and emulsification, with the contribution of photochemical weathering assumed to be negligible. Here, we aim to test this assumption using Macondo well oil released during the Deepwater Horizon spill as a case study. Our results indicate that the effects of photochemical weathering on Deepwater Horizon oil properties and dispersant effectiveness can greatly outweigh the effects of evaporative weathering. The decrease in dispersant effectiveness after light exposure was principally driven by the decreased solubility of photo-oxidized crude oil residues in the solvent system that comprises COREXIT EC9500A. Kinetic modeling combined with geospatial analysis demonstrated that a considerable fraction of aerial applications targeting Deepwater Horizon surface oil had low dispersant effectiveness. Collectively, the results of this study challenge the paradigm that photochemical weathering has a negligible impact on the effectiveness of oil spill response and provide critical insights into the “window of opportunity” to apply chemical dispersants in response to oil spills in sunlit waters.
    Description: This work was supported, in part, by National Science Foundation Grant OCE-1333148, Gulf of Mexico Research Initiative Grants 015, SA 16-30, the DEEP-C consortium, and the Clark Family Foundation, Inc. EPA funding was provided to R.N.C. from the Oil Spill Liability Trust Fund.
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 47
    Publication Date: 2022-05-25
    Description: This paper is not subject to U.S. copyright. The definitive version was published in Deep Sea Research Part II: Topical Studies in Oceanography 152 (2018): 67-81, doi:10.1016/j.dsr2.2018.05.020.
    Description: Ocean acidification (OA), driven by rising anthropogenic carbon dioxide (CO2), is rapidly advancing in the Pacific Arctic Region (PAR), producing conditions newly corrosive to biologically important carbonate minerals like aragonite. Naturally short linkages across the PAR food web mean that species-specific acidification stress can be rapidly transmitted across multiple trophic levels, resulting in widespread impacts. Therefore, it is critical to understand the formation, transport, and persistence of acidified conditions in the PAR in order to better understand and project potential impacts to this delicately balanced ecosystem. Here, we synthesize data from process studies across the PAR to show the formation of corrosive conditions in colder, denser winter-modified Pacific waters over shallow shelves, resulting from the combination of seasonal terrestrial and marine organic matter respiration with anthropogenic CO2. When these waters are subsequently transported off the shelf, they acidify the Pacific halocline. We estimate that Barrow Canyon outflow delivers ~2.24 Tg C yr-1 to the Arctic Ocean through corrosive winter water transport. This synthesis also allows the combination of spatial data with temporal data to show the persistence of these conditions in halocline waters. For example, one study in this synthesis indicated that 0.5–1.7 Tg C yr-1 may be returned to the atmosphere via air-sea gas exchange of CO2 during upwelling events along the Beaufort Sea shelf that bring Pacific halocline waters to the ocean surface. The loss of CO2 during these events is more than sufficient to eliminate corrosive conditions in the upwelled Pacific halocline waters. However, corresponding moored and discrete data records indicate that potentially corrosive Pacific waters are present in the Beaufort shelfbreak jet during 80% of the year, indicating that the persistence of acidified waters in the Pacific halocline far outweighs any seasonal mitigation from upwelling. Across the datasets in this large-scale synthesis, we estimate that the persistent corrosivity of the Pacific halocline is a recent phenomenon that appeared between 1975 and 1985. Over that short time, these potentially corrosive waters originating over the continental shelves have been observed as far as the entrances to Amundsen Gulf and M’Clure Strait in the Canadian Arctic Archipelago. The formation and transport of corrosive waters on the Pacific Arctic shelves may have widespread impact on the Arctic biogeochemical system and food web reaching all the way to the North Atlantic.
    Description: National Science Foundation Grant PLR-1303617.
    Keywords: Ocean acidification ; Pacific Arctic ; Arctic Ocean ; East Siberian Sea ; Chukchi Sea ; Beaufort Sea ; Transport ; Arctic Rivers ; Sea Ice ; Respiration ; Upwelling ; Biological vulnerability ; Community resilience
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 48
    Publication Date: 2022-05-25
    Description: © The Author(s), 2018. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Remote Sensing of Environment 209 (2018): 677-699, doi:10.1016/j.rse.2018.02.075.
    Description: We analyse ten years of QuikSCAT satellite surface winds to statistically characterize the spatio-temporal variability of the westward mountain-gap wind jets over the northern Red Sea. These wind jets bring relatively cold and dry air from the Arabian Desert, increasing heat loss and evaporation over the region similar to cold-air outbreaks from mid and subpolar latitudes. QuikSCAT captures the spatial structure of the wind jets and agrees well with in situ observations from a heavily instrumented mooring in the northern Red Sea. The local linear correlations between QuikSCAT and in situ winds are 0.96 (speed) and 0.85 (direction). QuikSCAT also reveals that cross-axis winds such as the mountain-gap wind jets are a major component of the regional wind variability. The cross-axis wind pattern appears as the second (or third) mode in the four vector Empirical Orthogonal Function analyses we performed, explaining between 6% to 11% of the wind variance. Westward wind jets are typical in winter, especially in December and January, but with strong interannual variability. Several jets can occur simultaneously and cover a large latitudinal range of the northern Red Sea, which we call large-scale westward events. QuikSCAT recorded 18 large-scale events over ten years, with duration between 3 to 8 days and strengths varying from 3–4 to 9–10 m/s. These events cause large changes in the wind stress curl pattern, imposing a remarkable sequence of positive and negative curl along the Red Sea main axis, which might be a wind forcing mechanism for the oceanic mesoscale circulation.
    Description: This work was supported by NSF grant OCE-1435665 and NASA grant NNX14AM71G.
    Keywords: QuikSCAT ; Air-sea interaction ; Wind jets ; Mountain gap ; Evaporation ; Heat loss
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 49
    Publication Date: 2022-05-25
    Description: This paper is not subject to U.S. copyright. The definitive version was published in Coastal Engineering 136 (2018): 147-160, doi:10.1016/j.coastaleng.2018.01.003.
    Description: The performance of a linear depth inversion algorithm, cBathy, applied to coastal video imagery was assessed using observations of water depth from vessel-based hydrographic surveys and in-situ altimeters for a wide range of wave conditions (0.3 〈 significant wave height 〈 4.3 m) on a sandy Atlantic Ocean beach near Duck, North Carolina. Comparisons of video-based cBathy bathymetry with surveyed bathymetry were similar to previous studies (root mean square error (RMSE) = 0.75 m, bias = −0.26 m). However, the cross-shore locations of the surfzone sandbar in video-derived bathymetry were biased onshore 18–40 m relative to the survey when offshore wave heights exceeded 1.2 m or were greater than half of the bar crest depth, and broke over the sandbar. The onshore bias was 3–4 m when wave heights were less than 0.8 m and were not breaking over the sandbar. Comparisons of video-derived seafloor elevations with in-situ altimeter data at three locations onshore of, near, and offshore of the surfzone sandbar over ∼1 year provide the first assessment of the cBathy technique over a wide range of wave conditions. In the outer surf zone, video-derived results were consistent with long-term patterns of bathymetric change (r2 = 0.64, RMSE = 0.26 m, bias = −0.01 m), particularly when wave heights were less than 1.2 m (r2 = 0.83). However, during storms when wave heights exceeded 3 m, video-based cBathy over-estimated the depth by up to 2 m. Near the sandbar, the sign of depth errors depended on the location relative to wave breaking, with video-based depths overestimated (underestimated) offshore (onshore) of wave breaking in the surfzone. Wave speeds estimated by video-based cBathy at the initiation of wave breaking often were twice the speeds predicted by linear theory, and up to three times faster than linear theory during storms. Estimated wave speeds were half as fast as linear theory predictions at the termination of wave breaking shoreward of the sandbar. These results suggest that video-based cBathy should not be used to track the migration of the surfzone sandbar using data when waves are breaking over the bar nor to quantify morphological evolution during storms. However, these results show that during low energy conditions, cBathy estimates could be used to quantify seasonal patterns of seafloor evolution.
    Description: This research was funded by the U.S. Army Corps of Engineers Coastal Field Data Collection Program, the Deputy Assistant Secretary of the Army for Research and Technology under ERDC's research program titled “Force Projection Entry Operations, STO D.GRD.2015.34”, the U.S. Naval Research Laboratory base program from the Office of Naval Research, a Vannevar Bush Faculty Fellowship funded by the Assistant Secretary of Defense for Research and Engineering, and the National Science Foundation.
    Keywords: Remote sensing ; Beach morphology ; Depth inversion ; Bathymetry estimation ; Video imaging ; Surfzone
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 50
    Publication Date: 2022-05-25
    Description: © The Author(s), 2018. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Geochimica et Cosmochimica Acta 228 (2018): 95-118, doi:10.1016/j.gca.2018.01.021.
    Description: Hosted in basaltic substrate on the ultra-slow spreading Mid-Cayman Rise, the Piccard hydrothermal field is the deepest currently known seafloor hot-spring (4957–4987 m). Due to its great depth, the Piccard site is an excellent natural system for investigating the influence of extreme pressure on the formation of submarine vent fluids. To investigate the role of rock composition and deep circulation conditions on fluid chemistry, the abundance and isotopic composition of organic, inorganic, and dissolved volatile species in high temperature vent fluids at Piccard were examined in samples collected in 2012 and 2013. Fluids from the Beebe Vents and Beebe Woods black smokers vent at a maximum temperature of 398 °C at the seafloor, however several lines of evidence derived from inorganic chemistry (Cl, SiO2, Ca, Br, Fe, Cu, Mn) support fluid formation at much higher temperatures in the subsurface. These high temperatures, potentially in excess of 500 °C, are attainable due to the great depth of the system. Our data indicate that a single deep-rooted source fluid feeds high temperature vents across the entire Piccard field. High temperature Piccard fluid H2 abundances (19.9 mM) are even higher than those observed in many ultramafic-influenced systems, such as the Rainbow (16 mM) and the Von Damm hydrothermal fields (18.2 mM). In the case of Piccard, however, these extremely high H2 abundances can be generated from fluid-basalt reaction occurring at very high temperatures. Magmatic and thermogenic sources of carbon in the high temperature black smoker vents are described. Dissolved ΣCO2 is likely of magmatic origin, CH4 may originate from a combination of thermogenic sources and leaching of abiotic CH4 from mineral-hosted fluid inclusions, and CO abundances are at equilibrium with the water–gas shift reaction. Longer-chained n-alkanes (C2H6, C3H8, n-C4H10, i-C4H10) may derive from thermal alteration of dissolved and particulate organic carbon sourced from the original seawater source, entrainment of microbial ecosystems peripheral to high temperature venting, and/or abiotic mantle sources. Dissolved ΣHCOOH in the Beebe Woods fluid is consistent with thermodynamic equilibrium for abiotic production via ΣCO2 reduction with H2 at 354 °C measured temperature. A lack of ΣHCOOH in the relatively higher temperature 398 °C Beebe Vent fluids demonstrates the temperature sensitivity of this equilibrium. Abundant basaltic seafloor outcrops and the axial location of the vent field, along with multiple lines of geochemical evidence, support extremely high temperature fluid-rock reaction with mafic substrate as the dominant control on Piccard fluid chemistry. These results expand the known diversity of vent fluid composition, with implications for supporting microbiological life in both the modern and ancient ocean.
    Description: This work was supported by the National Aeronautics and Space Administration (NASA) Astrobiology Science and Technology for Exploring Planets program [award number NNX09AB75G to CRG and JSS]; and the National Science Foundation [award number OCE-1061863 to CRG and JSS].
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 51
    Publication Date: 2022-05-25
    Description: © The Author(s), 2018. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Earth and Planetary Science Letters 487 (2018): 165-178, doi:10.1016/j.epsl.2018.01.032.
    Description: A new geospeedometer is developed based on the differential closures of Mg and rare earth element (REE) bulk-diffusion between coexisting plagioclase and clinopyroxene. By coupling the two elements with distinct bulk closure temperatures, this speedometer can numerically solve the initial temperatures and cooling rates for individual rock samples. As the existing Mg-exchange thermometer was calibrated for a narrow temperature range and strongly relies on model-dependent silica activities, a new thermometer is developed using literature experimental data. When the bulk closure temperatures of Mg and REE are determined, respectively, using this new Mg-exchange thermometer and the existing REE-exchange thermometer, this speedometer can be implemented for a wide range of compositions, mineral modes, and grain sizes. Applications of this new geospeedometer to oceanic gabbros from the fast-spreading East Pacific Rise at Hess Deep reveal that the lower oceanic crust crystallized at temperatures of 998–1353 °C with cooling rates of 0.003–10.2 °C/yr. Stratigraphic variations of the cooling rates and crystallization temperatures support deep hydrothermal circulations and in situ solidification of various replenished magma bodies. Together with existing petrological, geochemical and geophysical evidence, results from this new speedometry suggest that the lower crust formation at fast-spreading mid-ocean ridges involves emplacement of primary mantle melts in the deep section of the crystal mush zone coupled with efficient heat removal by crustal-scale hydrothermal circulations. The replenished melts become chemically and thermally evolved, accumulate as small magma bodies at various depths, feed the shallow axial magma chamber, and may also escape from the mush zone to generate off-axial magma lenses.
    Description: C. Sun acknowledges support from the Devonshire postdoctoral scholarship at WHOI and NSF grant OCE-1637130. This work was also supported by Natural Environment Research Council (NERC) Grant NE/I001670/1 to J. Lissenberg.
    Keywords: Oceanic crust ; Cooling rate ; Crystallization temperature ; Plagioclase ; Clinopyroxene ; Hess Deep
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 52
    Publication Date: 2022-05-25
    Description: This paper is not subject to U.S. copyright. The definitive version was published in Marine and Petroleum Geology 19 (2002): 971-987, doi:10.1016/S0264-8172(02)00132-0.
    Description: Considerable crustal thickness variations are inferred along Cayman Trough, a slow-spreading ocean basin in the Caribbean Sea, from modeling of the gravity field. The crust to a distance of 50 km from the spreading center is only 2–3 km thick in agreement with dredge and dive results. Crustal thickness increases to ∼5.5 km at distances between 100 and 430 km west of the spreading center and to 3.5–6 km at distances between 60 and 370 km east of the spreading center. The increase in thickness is interpreted to represent serpentinization of the uppermost mantle lithosphere, rather than a true increase in the volume of accreted ocean crust. Serpentinized peridotite rocks have indeed been dredged from the base of escarpments of oceanic crust rocks in Cayman Trough. Laboratory-measured density and P-wave speed of peridotite with 40–50% serpentine are similar to the observed speed in published refraction results and to the inferred density from the model. Crustal thickness gradually increases to 7–8 km at the far ends of the trough partially in areas where sea floor magnetic anomalies were identified. Basement depth becomes gradually shallower starting 250 km west of the rise and 340 km east of the rise, in contrast to the predicted trend of increasing depth to basement from cooling models of the oceanic lithosphere. The gradual increase in apparent crustal thickness and the shallowing trend of basement depth are interpreted to indicate that the deep distal parts of Cayman Trough are underlain by highly attenuated crust, not by a continuously accreted oceanic crust.
    Description: DFC was partly supported by NSF grant EAR-92-19796.
    Keywords: Caribbean plate ; Cayman trough ; Continental margins ; Gravity anomalies ; Serpentinized peridotite ; Slow spreading
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 53
    Publication Date: 2022-05-25
    Description: © The Author(s), 2018. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Marine Chemistry 206 (2018): 7-18, doi:10.1016/j.marchem.2018.08.005.
    Description: The lateral export of carbon from coastal marshes via tidal exchange is a key component of the marsh carbon budget and coastal carbon cycles. However, the magnitude of this export has been difficult to accurately quantify due to complex tidal dynamics and seasonal cycling of carbon. In this study, we use in situ, high-frequency measurements of dissolved inorganic carbon (DIC) and water fluxes to estimate lateral DIC fluxes from a U.S. northeastern salt marsh. DIC was measured by a CHANnelized Optical Sensor (CHANOS) that provided an in situ concentration measurement at 15-min intervals, during periods in summer (July – August) and late fall (December). Seasonal changes in the marsh had strong effects on DIC concentrations, while tidally-driven water fluxes were the fundamental vehicle of marsh carbon export. Episodic events, such as groundwater discharge and mean sea water level changes, can impact DIC flux through altered DIC concentrations and water flow. Variability between individual tides within each season was comparable to mean variability between the two seasons. Estimated mean DIC fluxes based on a multiple linear regression (MLR) model of DIC concentrations and high-frequency water fluxes agreed reasonably well with those derived from CHANOS DIC measurements for both study periods, indicating that high-frequency, modeled DIC concentrations, coupled with continuous water flux measurements and a hydrodynamic model, provide a robust estimate of DIC flux. Additionally, an analysis of sampling strategies revealed that DIC fluxes calculated using conventional sampling frequencies (hourly to two-hourly) of a single tidal cycle are unlikely to capture a representative mean DIC flux compared to longer-term measurements across multiple tidal cycles with sampling frequency on the order of tens of minutes. This results from a disproportionately large amount of the net DIC flux occurring over a small number of tidal cycles, while most tides have a near-zero DIC export. Thus, high-frequency measurements (on the order of tens of minutes or better) over the time period of interest are necessary to accurately quantify tidal exports of carbon species from salt marshes.
    Description: This work was funded by NSF Graduate Research Fellowship Program, NSF Ocean Sciences Postdoctoral Fellowship (OCE-1323728), Link FoundationOcean Engineering and Instrumentation Fellowship, National Institute of Science and Technology (NIST no. 60NANB10D024), the USGS LandCarbon and Coastal & Marine Geology Programs, NSF Chemical Oceanography Program (OCE-1459521), NSF Ocean Technology and Interdisciplinary Coordination program (OCE-1233654) and NOAA Science Collaborative (NA09NOS4190153).
    Keywords: Dissolved inorganic carbon ; Carbon export ; Salt marshes ; Wetlands
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 54
    Publication Date: 2022-05-25
    Description: This paper is not subject to U.S. copyright. The definitive version was published in Marine Geology 337 (2013): 53-66, doi:10.1016/j.margeo.2013.01.005.
    Description: Submarine canyons are common features of continental margins worldwide. They are conduits that funnel vast quantities of sediment from the continents to the deep sea. Though it is known that submarine canyons form primarily from erosion induced by submarine sediment flows, we currently lack quantitative, empirically based expressions that describe the morphology of submarine canyon networks. Multibeam bathymetry data along the entire passive US Atlantic margin (USAM) and along the active central California margin near Monterey Bay provide an opportunity to examine the fine-scale morphology of 171 slope-sourced canyons. Log–log regression analyses of canyon thalweg gradient (S) versus up-canyon catchment area (A) are used to examine linkages between morphological domains and the generation and evolution of submarine sediment flows. For example, canyon reaches of the upper continental slope are characterized by steep, linear and/or convex longitudinal profiles, whereas reaches farther down canyon have distinctly concave longitudinal profiles. The transition between these geomorphic domains is inferred to represent the downslope transformation of debris flows into erosive, canyon-flushing turbidity flows. Over geologic timescales this process appears to leave behind a predictable geomorphic fingerprint that is dependent on the catchment area of the canyon head. Catchment area, in turn, may be a proxy for the volume of sediment released during geomorphically significant failures along the upper continental slope. Focused studies of slope-sourced submarine canyons may provide new insights into the relationships between fine-scale canyon morphology and down-canyon changes in sediment flow dynamics.
    Keywords: Turbidity flow ; Debris flow ; Multibeam bathymetry ; Regression ; Power law ; Landslide
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 55
    Publication Date: 2020-03-09
    Description: Stream chemistry reflects the mixture of complex biogeochemical reactions that vary across space and time within watersheds. For example, streams experience changing hydrologic connectivity to heterogeneous water sources under different flow regimes; however, it remains unclear how seasonal flow paths link these different sources and regulate concentration-discharge behavior, i.e., changes in stream solute concentration as a function of discharge. At the Susquehanna Shale Hills Critical Zone Observatory (SSHCZO) in central Pennsylvania, USA, concentrations of chemostatic solutes (K, Mg, Na, Si, Cl) vary little across a wide range of discharge values while concentrations of chemodynamic solutes (Fe, Mn, Ca) decrease sharply with increasing stream discharge. To elucidate controls on chemodynamic solute behavior, we investigated the chemistry of surface water and shallow subsurface water at the SSHCZO in early autumn when discharge was negligible and concentrations of chemodynamic solutes were high. Dissolved ions, colloids, and micron-sized particles were extracted from hillslope soils and stream sediments to evaluate how elements were mobilized into pore waters and transported from hillslopes to the stream. During the study period when flow was intermittent, the stream consisted of isolated puddles that were chemically variable along the length of the channel. Inputs of subsurface water to the stream were limited to an area of upwelling near the stream headwaters, and the water table remained over a meter below the stream bed along the rest of the channel. Chemodynamic elements Fe and Mn were preferentially mobilized from organic-rich soils as a mixture of dissolved ions, colloids, and micron-sized particles; consequently, subsurface water draining organic-rich soils in the upper catchment was enriched in Fe and Mn. Conversely, Ca increased towards the catchment outlet and was primarily mobilized from stream sediments as Ca2+. Concentrations of chemostatic solutes were relatively invariable throughout the catchment. We conclude that chemodynamic behavior at SSHCZO is driven by seasonally variable connectivity between the stream and hillslope soils. During the dry season, stream water derives from a shallow perched water table (interflow) that upwells to generate metal-rich stream headwaters. High concentrations of soluble Fe and Mn at low discharge occur when metal-rich headwaters are flushed to the catchment outlet during periodic rain events. Interflow during the dry season originates from water that infiltrates through organic-rich swales; thus, metals in the stream at low flow are ultimately derived from convergent hillslopes where biological processes have concentrated and/or mobilized these chemodynamic elements. In contrast, high concentrations of Ca2+ at low discharge are likely mobilized from stream sediments that contain secondary calcite precipitates. We infer that chemodynamic solutes are diluted at high discharge primarily due to increased flow through planar hillslopes. This study highlights how spatially heterogeneous biogeochemistry and seasonally variable flow paths regulate concentration-discharge behavior within catchments.
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , peerRev
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 56
    Publication Date: 2022-06-06
    Description: A network of shear zones that evolved through the brittle-ductile transition is exposed in the Calamita Schists, Elba Island, Italy. The shear zones formed during Late Miocene contractional deformation coeval with high grade contact metamorphism (∼650 °C) related to the emplacement of plutonic rocks at shallow crustal levels (∼7–10 Km). An early stage high metamorphic grade foliation was overprinted by mylonitic deformation that progressively localized on low-metamorphic grade shear bands producing S-C mylonites during cooling of contact aureole. Localization of deformation on shear bands was driven by temperature decrease that triggered strain partitioning between ‘hard’ high grade relics and ‘soft’ shear bands. Softening of shear bands occurred likely due to fluid influx and retrograde growth of fine-grained phyllosilicates. The interconnection of anastomosing shear bands and passive rotation of the relic high grade foliation caused widening of the shear bands producing mylonites with a composite mylonitic foliation and C′ shear bands. An estimate of the vorticity number Wk of the flow of ∼0.3–0.5 was obtained from the orientation of C′ shear bands measured at the meso- and thin sectionscale. Close to the brittle-ductile transition, the growth of soft phyllosilicates allowed C′ shear bands to act as precursory structures to brittle deformation localized into an array of low-angle faults and shear fractures.
    Description: Published
    Description: 100-114
    Description: 1T. Struttura della Terra
    Description: JCR Journal
    Keywords: Brittle-ductile transition ; Mylonite Shear zone ; Shear band Faulting ; Strain localization ; Structural geology, brittle ductile transition
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 57
    Publication Date: 2022-06-09
    Description: To obtain a 3-D crustal density and shear-wave velocity structure beneath the Po plain we exploit seismic records gathered from 2006 to 2014 and Bouguer gravity data assembled for the last estimation of the Italian Geoid. 2-D maps for both Love and Rayleigh fundamental mode at periods between 4 and 20 s are obtained applying a tomographic inversion. The defined local dispersion curves are then jointly inverted using a linearized scheme to obtain a 3-D isotropic shear-wave velocity model across the Po plain region. The model, transformed into density through a priori velocity-density relationships, is then the input of the Sequential Integrated Inversion algorithm, which enables us to recover a new 3-D density-shear wave velocity coupling and inferences on the lithology and tectonics. Low and fast S-wave velocities are highlighted for the shallow Pliocene–Quaternary sediments along the foredeep, in front of the Northern Apennines, and for the presence of limestone units in the upper crust, respectively. Whereas sediment trends seem to be consistent with the results obtained, the Mesozoic carbonates, which are inherently characterized by high variability, are less resolved. A major result is the recovery of a high speed (3.3 km/s) - density (2.2 kg/m3) structure in the upper crust (6–10 km) localized beneath the arcuate Po plain thrust front expanding from the external margin of the Ferrara arc toward the Alps and the Adriatic Sea. At the boundaries of this brittle body, we locate earthquakes of the Emilia 2012 seismic sequence and the historical seismicity. Mapping lateral discontinuities in density and shear wave velocity could provide insights in defining strengthening and weakening zones, and in focusing on transition zones often prone to earthquakes.
    Description: Published
    Description: 262-279
    Description: 2TR. Ricostruzione e modellazione della struttura crostale
    Description: JCR Journal
    Keywords: Po plain ; 3D crustal model ; Surface waves ; Bouguer gravity anomalies
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 58
    Publication Date: 2022-05-26
    Description: © The Author(s), 2018. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Marine Geology 404 (2018): 1-14, doi:10.1016/j.margeo.2018.06.016.
    Description: Recent major storms have piqued interest in understanding the responses of estuarine hydrodynamics and sediment transport to these events. To that end, flow velocity, wave characteristics, and suspended-sediment concentration (SSC) were measured for 11 months at eight locations in Chincoteague Bay, MD/VA, USA, a shallow back-barrier estuary. Daily breezes and episodic storms generated sediment-resuspending waves and modified the flow velocity at all sites, which occupied channel, shoal, and sheltered-bay environments with different bed-sediment characteristics. Despite comparable SSC during calm periods, SSC at the channel locations was considerably greater than at the shoal sites during windy periods because of relatively more erodible bed sediment in the channels. Sediment fluxes were strongly wind modulated: within the bay's main channel, depth-integrated unit-width sediment flux increased nonlinearly with increasing wind speed. When averaged over all sites, about 35% of the flux occurred during windy periods (wind speed greater than 6 m s−1), which represented just 15% of the deployment time. At channel sites, the net water and sediment fluxes were opposite to the direction of the wind forcing, while at shoal sites, the fluxes generally were aligned with the wind, implying complex channel–shoal dynamics. Yearly sediment fluxes exceed previous estimates of sediment delivery to the entirety of Chincoteague Bay. These observations illustrate the dynamic sedimentary processes occurring within microtidal back-barrier lagoons and highlight the importance of storm events in the hydrodynamics and overall sediment budgets of these systems.
    Description: his study was part of the Estuarine Physical Response to Storms project (GS2-2D), supported by the Department of the Interior Hurricane Sandy Recovery program.
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 59
    Publication Date: 2022-05-26
    Description: © The Author(s), 2017. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Marine Geology 395 (2018): 301-319, doi:10.1016/j.margeo.2017.10.014.
    Description: A high-resolution multibeam echosounder (MBES) dataset covering over 279,000 km2 was acquired in the southeastern Indian Ocean to assist the search for Malaysia Airlines Flight 370 (MH370) that disappeared on 8 March 2014. The data provided an essential geospatial framework for the search and is the first large-scale coverage of MBES data in this region. Here we report on geomorphic analyses of the new MBES data, including a comparison with the Global Seafloor Geomorphic Features Map (GSFM) that is based on coarser resolution satellite altimetry data, and the insights the new data provide into geological processes that have formed and are currently shaping this remote deepsea area. Our comparison between the new MBES bathymetric model and the latest global topographic/bathymetric model (SRTM15_plus) reveals that 62% of the satellite-derived data points for the study area are comparable with MBES measurements within the estimated vertical uncertainty of the SRTM15_plus model (± 100 m). However, 〉 38% of the SRTM15_plus depth estimates disagree with the MBES data by 〉 100 m, in places by up to 1900 m. The new MBES data show that abyssal plains and basins in the study area are significantly more rugged than their representation in the GSFM, with a 20% increase in the extent of hills and mountains. The new model also reveals four times more seamounts than presented in the GSFM, suggesting more of these features than previously estimated for the broader region. This is important considering the ecological significance of high-relief structures on the seabed, such as hosting high levels of biodiversity. Analyses of the new data also enabled sea knolls, fans, valleys, canyons, troughs, and holes to be identified, doubling the number of discrete features mapped. Importantly, mapping the study area using MBES data improves our understanding of the geological evolution of the region and reveals a range of modern sedimentary processes. For example, a large series of ridges extending over approximately 20% of the mapped area, in places capped by sea knolls, highlight the preserved seafloor spreading fabric and provide valuable insights into Southeast Indian Ridge seafloor spreading processes, especially volcanism. Rifting is also recorded along the Broken Ridge – Diamantina Escarpment, with rift blocks and well-bedded sedimentary bedrock outcrops discernible down to 2400 m water depth. Modern ocean floor sedimentary processes are documented by sediment mass transport features, especially along the northern margin of Broken Ridge, and in pockmarks (the finest-scale features mapped), which are numerous south of Diamantina Trench and appear to record gas and/or fluid discharge from underlying marine sediments. The new MBES data highlight the complexity of the search area and serve to demonstrate how little we know about the vast areas of the ocean that have not been mapped with MBES. The availability of high-resolution and accurate maps of the ocean floor can clearly provide new insights into the Earth's geological evolution, modern ocean floor processes, and the location of sites that are likely to have relatively high biodiversity.
    Keywords: Indian Ocean ; Multibeam echosounder ; Geomorphology ; Processes ; Deepsea ; Seamount
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 60
    Publication Date: 2022-05-26
    Description: © The Author(s), 2017. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Ecological Modelling 368 (2018): 357-376, doi:10.1016/j.ecolmodel.2017.12.010.
    Description: Despite diel and seasonal vertical migrations (DVM and SVM) of high-latitude zooplankton have been studied since the late-19th century, questions still remain about the influence of environmental seasonality on vertical migration, and the combined influence of DVM and SVM on zooplankton fitness. Toward addressing these, we developed a model for simulating DVM and SVM of high-latitude herbivorous copepods in high spatio-temporal resolution. In the model, a unique timing and amplitude of DVM and SVM and its ontogenetic trajectory were defined as a vertical strategy. Growth, survival and reproductive performances of numerous vertical strategies hardwired to copepods spawned in different times of the year were assessed by a fitness estimate, which was heuristically maximized by a Genetic Algorithm to derive the optimal vertical strategy for a given model environment. The modelled food concentration, temperature and visual predation risk had a significant influence on the observed vertical strategies. Under low visual predation risk, DVM was less pronounced, and SVM and reproduction occurred earlier in the season, where capital breeding played a significant role. Reproduction was delayed by higher visual predation risk, and copepods that spawned later in the season used the higher food concentrations and temperatures to attain higher growth, which was efficiently traded off for survival through DVM. Consequently, the timing of SVM did not change much from that predicted under lower visual predation risk, but the body and reserve sizes of overwintering stages and the importance of capital breeding diminished. Altogether, these findings emphasize the significance of DVM in environments with elevated visual predation risk and shows its contrasting influence on the phenology of reproduction and SVM, and moreover highlights the importance of conducting field and modeling work to study these migratory strategies in concert.
    Description: This project was funded by VISTA (project no. 6165), a basic research program in collaboration between The Norwegian Academy of Science and Letters and Statoil. ØV received funding from the Fulbright Arctic Initiative.
    Keywords: Vertical migration ; Seasonality ; Phenology ; Optimization model ; Genetic algorithm ; Habitat choice
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 61
    Publication Date: 2022-05-26
    Description: © The Author(s), 2017. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Marine Pollution Bulletin 126 (2018): 1-18, doi:10.1016/j.marpolbul.2017.10.034.
    Description: Loud sound emitted during offshore industrial activities can impact marine mammals. Regulations typically prescribe marine mammal monitoring before and/or during these activities to implement mitigation measures that minimise potential acoustic impacts. Using seismic surveys under low visibility conditions as a case study, we review which monitoring methods are suitable and compare their relative strengths and weaknesses. Passive acoustic monitoring has been implemented as either a complementary or alternative method to visual monitoring in low visibility conditions. Other methods such as RADAR, active sonar and thermal infrared have also been tested, but are rarely recommended by regulatory bodies. The efficiency of the monitoring method(s) will depend on the animal behaviour and environmental conditions, however, using a combination of complementary systems generally improves the overall detection performance. We recommend that the performance of monitoring systems, over a range of conditions, is explored in a modelling framework for a variety of species.
    Description: This work was supported by the Joint Industry Programme on E&P Sound and Marine Life - Phase III. TAM was partially supported by CEAUL (funded by FCT - Fundação para a Ciência e a Tecnologia, Portugal, through the project UID/MAT/00006/2013).
    Keywords: Marine mammals ; Monitoring methods ; Underwater noise ; Seismic survey ; Detection performance ; Low visibility
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 62
    Publication Date: 2022-05-26
    Description: © The Author(s), 2017. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Ocean Modelling 121 (2018): 49-75, doi:10.1016/j.ocemod.2017.11.008.
    Description: Lagrangian analysis is a powerful way to analyse the output of ocean circulation models and other ocean velocity data such as from altimetry. In the Lagrangian approach, large sets of virtual particles are integrated within the three-dimensional, time-evolving velocity fields. Over several decades, a variety of tools and methods for this purpose have emerged. Here, we review the state of the art in the field of Lagrangian analysis of ocean velocity data, starting from a fundamental kinematic framework and with a focus on large-scale open ocean applications. Beyond the use of explicit velocity fields, we consider the influence of unresolved physics and dynamics on particle trajectories. We comprehensively list and discuss the tools currently available for tracking virtual particles. We then showcase some of the innovative applications of trajectory data, and conclude with some open questions and an outlook. The overall goal of this review paper is to reconcile some of the different techniques and methods in Lagrangian ocean analysis, while recognising the rich diversity of codes that have and continue to emerge, and the challenges of the coming age of petascale computing.
    Description: EvS has received funding from the European Research Council (ERC) under the European Unions Horizon 2020 research and innovation programme (grant agreement No 715386). This research for PJW was supported as part of the Energy Exascale Earth System Model (E3SM) project, funded by the U.S. Department of Energy, Office of Science, Office of Biological and Environmental Research. Funding for HFD was provided by Grant No. DE-SC0012457 from the US Department of Energy. PB acknowledges support for this work from NERC grant NE/R011567/1. SFG is supported by NERC National Capability funding through the Extended Ellett Line Programme.
    Keywords: Ocean circulation ; Lagrangian analysis ; Connectivity ; Particle tracking ; Future modelling
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 63
    Publication Date: 2022-05-26
    Description: This paper is not subject to U.S. copyright. The definitive version was published in Geomorphology 300 (2018): 189-202, doi:10.1016/j.geomorph.2017.08.004.
    Description: Hurricane Sandy at Fire Island, New York presented unique challenges in the quantification of storm impacts using traditional metrics of coastal change, wherein measured changes (shoreline, dune crest, and volume change) did not fully reflect the substantial changes in sediment redistribution following the storm. We used a time series of beach profile data at Fire Island, New York to define a new contour-based morphologic change metric, the Beach Change Envelope (BCE). The BCE quantifies changes to the upper portion of the beach likely to sustain measurable impacts from storm waves and capture a variety of storm and post-storm beach states. We evaluated the ability of the BCE to characterize cycles of beach change by relating it to a conceptual beach recovery regime, and demonstrated that BCE width and BCE height from the profile time series correlate well with established stages of recovery. We also investigated additional applications of this metric to capture impacts from storms and human modification by applying it to several post-storm historical datasets in which impacts varied considerably; Nor'Ida (2009), Hurricane Irene (2011), Hurricane Sandy (2012), and a 2009 community replenishment. In each case, the BCE captured distinctive upper beach morphologic change characteristic of these different beach building and erosional events. Analysis of the beach state at multiple profile locations showed spatial trends in recovery consistent with recent morphologic island evolution, which other studies have linked with sediment availability and the geologic framework. Ultimately we demonstrate a new way of more effectively characterizing beach response and recovery cycles to evaluate change along sandy coasts.
    Description: This work was supported by the 2013 Disaster Relief Appropriations Act, Department of Interior Hurricane Sandy Supplemental Project GS2-2B.
    Keywords: Barrier Island ; Coastal geomorphology ; Storm response ; Beach recovery
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 64
    Publication Date: 2022-05-26
    Description: © The Author(s), 2017. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Marine Micropaleontology 138 (2018): 12-32, doi:10.1016/j.marmicro.2017.10.005.
    Description: We report systematic transmission electron microscope (TEM) observations of the cellular ultrastructure of selected, small rotalid benthic foraminifera. Nine species from different environments (intertidal mudflat, fjord, and basin) were investigated: Ammonia sp., Elphidium oceanense, Haynesina germanica, Bulimina marginata, Globobulimina sp., Nonionellina labradorica, Nonionella sp., Stainforthia fusiformis and Buliminella tenuata. All the observed specimens were fixed just after collection from their natural habitats allowing description of intact and healthy cells. Foraminiferal organelles can be divided into two broad categories: (1) organelles that are present in all eukaryotes, such as the nuclei, mitochondria, endoplasmic reticulum, Golgi apparatus, and peroxisomes; and (2) organelles observed in all foraminifera but not common in all eukaryotic cells, generally with unknown function, such as fibrillar vesicles or electron-opaque bodies. Although the organelles of the first category were observed in all the observed species, their appearance varies. For example, subcellular compartments linked to feeding and metabolism exhibited different sizes and shapes between species, likely due to differences in their diet and/or trophic mechanisms. The organelles of the second category are common in all foraminiferal species investigated and, according to the literature, are frequently present in the cytoplasm of many different species, both benthic and planktonic. This study, thus, provides a detailed overview of the major ultrastructural components in benthic foraminiferal cells from a variety of marine environments, and also highlights the need for further research to better understand the function and role of the various organelles in these fascinating organisms.
    Description: This work was supported by the Swiss National Science Foundation (grant no. 200021_149333), The Investment in Science Fund at WHOI and the French national program EC2CO-LEFE (project ForChlo). TJ was funded by the “FRESCO” project, a project supported by the Region Pays de Loire and the University of Angers.
    Keywords: Protist ; Organelles ; TEM ; Cytology ; Mudflat ; Gullmar Fjord
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 65
    Publication Date: 2022-05-26
    Description: © The Author(s), 2017. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Science of The Total Environment 621 (2018): 1185-1198, doi:10.1016/j.scitotenv.2017.10.109.
    Description: We made an assessment of the levels of radionuclides in the ocean waters, seafloor and groundwater at Bikini and Enewetak Atolls where the US conducted nuclear weapons tests in the 1940's and 50's. This included the first estimates of submarine groundwater discharge (SGD) derived from radium isotopes that can be used here to calculate radionuclide fluxes in to the lagoon waters. While there is significant variability between sites and sample types, levels of plutonium (239,240Pu) remain several orders of magnitude higher in lagoon seawater and sediments than what is found in rest of the world's oceans. In contrast, levels of cesium-137 (137Cs) while relatively elevated in brackish groundwater are only slightly higher in the lagoon water relative to North Pacific surface waters. Of special interest was the Runit dome, a nuclear waste repository created in the 1970's within the Enewetak Atoll. Low seawater ratios of 240Pu/239Pu suggest that this area is the source of about half of the Pu in the Enewetak lagoon water column, yet radium isotopes suggest that SGD from below the dome is not a significant Pu source. SGD fluxes of Pu and Cs at Bikini were also relatively low. Thus radioactivity associated with seafloor sediments remains the largest source and long term repository for radioactive contamination. Overall, Bikini and Enewetak Atolls are an ongoing source of Pu and Cs to the North Pacific, but at annual rates that are orders of magnitude smaller than delivered via close-in fallout to the same area.
    Description: Finally, none of this would have been possible without the generous financial support from the Dalio Explore Fund (WHOI #25531513) for the vessel and our post cruise analyses that together resulted in this unique and successful research program.
    Keywords: Marshall Islands ; Runit dome ; Plutonium ; Cesium ; Radium ; Nuclear weapons tests
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 66
    facet.materialart.
    Unknown
    Elsevier
    In:  EPIC3Marine Policy, Elsevier, 89, pp. 50-57, ISSN: 0308-597X
    Publication Date: 2024-02-07
    Description: The ‘Code of Conduct for Responsible Fisheries’ developed by the United Nations Food and Agriculture Organisation has been central for the governance of fisheries. Most responsible fisheries initiatives are market-driven and motivate transitions towards greener economies. These added-value fish economies have increasingly connected fishing grounds to external markets that demand high quality sustainable products. This article problematizes the framework of responsible fishing and examines its intersections with place-base institutional processes in the Pacific coast of Colombia. In doing this, it explores how the concept of ‘responsible fishing’ has been framed, arguing that it has been used to operationalize the expansion of neoliberal processes in the oceans. It draws on small-scale fisheries performed by Afro-descendant people in the Gulf of Tribugá, where responsible fishing narratives have been linked to the creation of marine protected areas and responsible fish supply chains. Two dominant framings of responsible fishing were identified; a 'sustainability’ framing that denotes the sustainable use of fishing resources, and a ‘technical’ framing that refers to the use of environmentally safe practices. However, none of these framings accounts for social responsibility. Instead they have enforced the division of fishing practices between ‘responsible’/‘irresponsible’, and produced static, ahistorical and oversimplified understandings of fishing dynamics. All this has triggered a local need for external control over fisheries governance, disempowering place-based control mechanisms. This article concludes by questioning whether responsible fishing can successfully ensure a sustainable use of fishing resources, or if moving beyond ‘responsibility’ is needed to strengthen local institutional processes and autonomy among coastal peoples.
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , isiRev
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 67
    Publication Date: 2018-08-09
    Print ISSN: 0276-7333
    Electronic ISSN: 1520-6041
    Topics: Chemistry and Pharmacology
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 68
    Publication Date: 2018-08-09
    Print ISSN: 0276-7333
    Electronic ISSN: 1520-6041
    Topics: Chemistry and Pharmacology
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 69
    Publication Date: 2018-08-14
    Print ISSN: 0276-7333
    Electronic ISSN: 1520-6041
    Topics: Chemistry and Pharmacology
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 70
    Publication Date: 2018-08-15
    Print ISSN: 0276-7333
    Electronic ISSN: 1520-6041
    Topics: Chemistry and Pharmacology
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 71
  • 72
    Publication Date: 2018-11-15
    Print ISSN: 0276-7333
    Electronic ISSN: 1520-6041
    Topics: Chemistry and Pharmacology
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 73
    Publication Date: 2018-11-14
    Print ISSN: 0276-7333
    Electronic ISSN: 1520-6041
    Topics: Chemistry and Pharmacology
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 74
    Publication Date: 2018-08-07
    Print ISSN: 0276-7333
    Electronic ISSN: 1520-6041
    Topics: Chemistry and Pharmacology
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 75
  • 76
    Publication Date: 2018-11-08
    Print ISSN: 0276-7333
    Electronic ISSN: 1520-6041
    Topics: Chemistry and Pharmacology
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 77
    Publication Date: 2018-08-14
    Print ISSN: 0276-7333
    Electronic ISSN: 1520-6041
    Topics: Chemistry and Pharmacology
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 78
    Publication Date: 2018-10-17
    Print ISSN: 0276-7333
    Electronic ISSN: 1520-6041
    Topics: Chemistry and Pharmacology
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 79
    Publication Date: 2018-08-31
    Print ISSN: 0276-7333
    Electronic ISSN: 1520-6041
    Topics: Chemistry and Pharmacology
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 80
    Publication Date: 2018-09-06
    Print ISSN: 0276-7333
    Electronic ISSN: 1520-6041
    Topics: Chemistry and Pharmacology
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 81
    Publication Date: 2018-09-10
    Print ISSN: 0276-7333
    Electronic ISSN: 1520-6041
    Topics: Chemistry and Pharmacology
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 82
    Publication Date: 2018-12-24
    Print ISSN: 0276-7333
    Electronic ISSN: 1520-6041
    Topics: Chemistry and Pharmacology
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 83
    Publication Date: 2018-06-21
    Print ISSN: 0276-7333
    Electronic ISSN: 1520-6041
    Topics: Chemistry and Pharmacology
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 84
  • 85
    Publication Date: 2018-08-27
    Print ISSN: 0276-7333
    Electronic ISSN: 1520-6041
    Topics: Chemistry and Pharmacology
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 86
  • 87
    Publication Date: 2018-10-15
    Print ISSN: 0276-7333
    Electronic ISSN: 1520-6041
    Topics: Chemistry and Pharmacology
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 88
    Publication Date: 2018-08-16
    Print ISSN: 0276-7333
    Electronic ISSN: 1520-6041
    Topics: Chemistry and Pharmacology
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 89
  • 90
    Publication Date: 2018-11-07
    Print ISSN: 0276-7333
    Electronic ISSN: 1520-6041
    Topics: Chemistry and Pharmacology
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 91
    Publication Date: 2018-08-08
    Print ISSN: 0276-7333
    Electronic ISSN: 1520-6041
    Topics: Chemistry and Pharmacology
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 92
    Publication Date: 2018-07-30
    Print ISSN: 0276-7333
    Electronic ISSN: 1520-6041
    Topics: Chemistry and Pharmacology
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 93
    Publication Date: 2018-03-01
    Electronic ISSN: 1948-7185
    Topics: Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 94
    Publication Date: 2018-03-01
    Electronic ISSN: 1948-7185
    Topics: Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 95
  • 96
  • 97
  • 98
    Publication Date: 2018-02-14
    Electronic ISSN: 1948-7185
    Topics: Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 99
  • 100
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...