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  • Artikel  (7)
  • 04.07. Tectonophysics  (4)
  • Acoustics  (3)
  • MDPI  (4)
  • Frontiers Media  (3)
  • 2020-2022  (4)
  • 2015-2019  (3)
  • 1945-1949
  • 1
    Publikationsdatum: 2021-01-04
    Beschreibung: Following the 2004 seismic unrest at Tenerife and the 2011–2012 submarine eruption at El Hierro, the number of Global Navigation Satellite System (GNSS) observation sites in the Canary Islands (Spain) has increased, offering scientists a useful tool with which to infer the kinematics and present-day surface deformation of the Canary sector of the Atlantic Ocean. We take advantage of the common-mode component filtering technique to improve the signal-to-noise ratio of the velocities retrieved from the daily solutions of 18 permanent GNSS stations distributed in the Canaries. The analysis of GNSS time series spanning the period 2011–2017 enabled us to characterize major regions of deformation along the archipelago through the mapping of the 2D infinitesimal strain field. By applying the triangular segmentation approach to GNSS velocities, we unveil a variable kinematic behaviour within the islands. The retrieved extension pattern shows areas of maximum deformation west of Tenerife, Gran Canaria and Fuerteventura. For the submarine main seismogenic fault between Tenerife and Gran Canaria, we simulated the horizontal deformation and strain due to one of the strongest (mbLg 5.2) earthquakes of the region. The seismic areas between islands, mainly offshore Tenerife and Gran Canaria, seem mainly influenced by the regional tectonic stress, not the local volcanic activity. In addition, the analysis of the maximum shear strain confirms that the regional stress field influences the E–W and NE–SW tectonic lineaments, which, in accordance with the extensional and compressional tectonic regimes identified, might favour episodes of volcanism in the Canary Islands.
    Beschreibung: Published
    Beschreibung: 3297
    Beschreibung: 2T. Deformazione crostale attiva
    Beschreibung: 6V. Pericolosità vulcanica e contributi alla stima del rischio
    Beschreibung: JCR Journal
    Schlagwort(e): GNSS time series ; kinematics and ground deformation ; Canary Islands ; 04.02. Exploration geophysics ; 04.03. Geodesy ; 04.07. Tectonophysics ; 04.08. Volcanology
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
    Standort Signatur Erwartet Verfügbarkeit
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  • 2
    Publikationsdatum: 2021-01-07
    Beschreibung: We present a novel inverse method for discriminating regional deformation and long-term fault creep by inversion of GNSS velocities observed at the spatial scale of intraplate faults by exploiting the different spatial signatures of these two mechanisms. In doing so our method provides a refined estimate of the upper bound of the strain accumulation process. As case study, we apply this method to a six year GNSS campaign (2003–2008) set up in the southern portion of the Pollino Range over the Castrovillari and Pollino faults. We show that regional deformation alone cannot explain the observed deformation pattern and implies high geodetic strain rate, with a WSW-ENE extension of 86±41×10−9/yr. Allowing for the possibility of fault creep, the modelling of GNSS velocities is consistent with their uncertainties and they are mainly explained by a shallow creep over the Pollino fault, with a normal/strike-slip mechanism up to 5 mm/yr. The regional strain rate decrease by about 70 percent and is characterized by WNW-ESE extension of 24±28×10−9/yr. The large uncertainties affecting our estimate of regional strain rate do not allow infering whether the tectonic regime of the area is extensional or strike-slip, although the latter is slightly more likely
    Beschreibung: Published
    Beschreibung: 2921
    Beschreibung: 2T. Deformazione crostale attiva
    Beschreibung: JCR Journal
    Schlagwort(e): regional deformation ; fault creep ; GNSS velocities ; inverse theory ; 04. Solid Earth ; 04.03. Geodesy ; 04.07. Tectonophysics
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
    Standort Signatur Erwartet Verfügbarkeit
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  • 3
    Publikationsdatum: 2021-01-19
    Beschreibung: Using an analyticalmethodology taking into account heat flowdensity data, frictional heating, temperature variations due to the re-equilibrated conductive state after thrusting and geological constrains, we calculated surface heat flow, geotherms and isotherms along a balanced and restored regional geological cross-section. Our results highlight the impact of frictional heating produced by thrusts on the thermal structure of the study area, leading to a raising of the isotherms both in the inner Albanides to the E and in the Adriatic sector offshore. Minimum values of Qs in the surroundings of Tirana and the reconstructed 2D thermal structure suggest less favorable conditions for exploitation of geothermal energy, besides the direct use (Borehole Heat Exchanger-Geothermal Heat Pump systems). Nevertheless, the occurrence of the “Kruja geothermal zone”, partially overlapping this area and including hot springmanifestations, emphasize the structural control in driving hot fluids to the surface with respect to the regional thermal structure.
    Beschreibung: Published
    Beschreibung: 6028
    Beschreibung: 1T. Struttura della Terra
    Beschreibung: JCR Journal
    Schlagwort(e): balanced cross-sections ; thermal modeling ; fold and thrust belts ; frictional heating ; 04.07. Tectonophysics
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
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  • 4
    Publikationsdatum: 2021-01-19
    Beschreibung: The Zagros thrust belt is a large orogenic zone located along the southwest region of Iran. To obtain a better knowledge of this important mountain chain, we elaborated the first 3-D model reproducing the thermal structure of its northwestern part, i.e., the Lurestan arc. This study is based on a 3-D structural model obtained using published geological sections and available information on the depth of the Moho discontinuity. The analytical calculation procedure took into account the temperature variation due to: (1) The re-equilibrated conductive state after thrusting, (2) frictional heating, (3) heat flow density data, and (4) a series of geologically derived constraints. Both geotherms and isotherms were obtained using this analytical methodology. The results pointed out the fundamental control exerted by the main basement fault of the region, i.e., the Main Frontal Thrust (MFT), in governing the thermal structure of the crust, the main parameter being represented by the amount of basement thickening produced by thrusting. This is manifested by more densely spaced isotherms moving from the southwestern foreland toward the inner parts of orogen, as well as in a lateral variation related with an along-strike change from a moderately dipping crustal ramp of the MFT to the NW to a gently dipping crustal ramp to the SE. The complex structural architecture, largely associated with late-stage (Pliocene) thick-skinned thrusting, results in a zone of relatively high geothermal gradient in the easternmost part of the study area. Our thermal model of a large crustal volume, besides providing new insights into the geodynamic processes affecting a major salient of the Zagros thrust belt, may have important implications for seismotectonic analysis in an area recently affected by a Mw = 7.3 earthquake, as well as for geothermal/hydrocarbon exploration in the highly perspective Lurestan region.
    Beschreibung: Published
    Beschreibung: 2140
    Beschreibung: 1T. Struttura della Terra
    Beschreibung: JCR Journal
    Schlagwort(e): active tectonics ; heat flow ; 3-D thermal modelling ; thermal structure ; temperature profile ; 04.07. Tectonophysics
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
    Standort Signatur Erwartet Verfügbarkeit
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  • 5
    Publikationsdatum: 2022-05-25
    Beschreibung: © The Author(s), 2018. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Frontiers in Marine Science 5 (2018): 158, doi:10.3389/fmars.2018.00158.
    Beschreibung: In autumn 2015, several sources reported observations of large amounts of gelatinous material in a large north Norwegian fjord system, either caught when trawling for other organisms or fouling fishing gear. The responsible organism was identified as a physonect siphonophore, Nanomia cara, while a ctenophore, Beroe cucumis, and a hydromedusa, Modeeria rotunda, were also registered in high abundances on a couple of occasions. To document the phenomena, we have compiled a variety of data from concurrent fisheries surveys and local fishermen, including physical samples, trawl catch, and acoustic data, photo and video evidence, and environmental data. Because of the gas-filled pneumatophore, characteristic for these types of siphonophores, acoustics provided detailed and unique insight to the horizontal and vertical distribution and potential abundances (~0.2–20 colonies·m−3) of N. cara with the highest concentrations observed in the near bottom region at ~320 m depth in the study area. This suggests that these animals were retained and accumulated in the deep basins of the fjord system possibly blooming here because of favorable environmental conditions and potentially higher prey availability compared to the shallower shelf areas to the north. Few cues as to the origin and onset of the bloom were found, but it may have originated from locally resident siphonophores. The characteristics of the deep-water masses in the fjord basins were different compared to the deep water outside the fjord system, suggesting no recent deep-water import to the fjords. However, water-masses containing siphonophores (not necessarily very abundant), may have been additionally introduced to the fjords at intermediate depths, with the animals subsequently trapped in the deeper fjord basins. The simultaneous observations of abundant siphonophores, hydromedusae, and ctenophores in the Lyngen-Kvænangen fjord system are intriguing, but difficult to provide a unified explanation for, as the organisms differ in their biology and ecology. Nanomia and Beroe spp. are holopelagic, while M. rotunda has a benthic hydroid stage. The species also have different trophic ecologies and dietary preferences. Only by combining information from acoustics, trawling, genetics, and local fishermen, were the identity, abundance, and the vertical and horizontal distribution of the physonect siphonophore, N. cara, established.
    Beschreibung: The work was funded by the Ministry of Fisheries and Coastal Affairs through the Institute of Marine Research (IMR), while the Research Council of Norway (RCN) is thanked for the financial support through the project The Arctic Ocean Ecosystem—(SI_ARCTIC, RCN 228896). AH was supported by the Norwegian Taxonony Initiative (NTI 70184233) and ForBio Research School funding (RCN 248799 and NTI 70184215).
    Schlagwort(e): Jellyfish bloom ; Genetics ; Acoustics ; Nanomia ; North Norwegian fjords ; Gelatinous zooplankton
    Repository-Name: Woods Hole Open Access Server
    Materialart: Article
    Standort Signatur Erwartet Verfügbarkeit
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  • 6
    Publikationsdatum: 2022-05-26
    Beschreibung: © The Author(s), 2017. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Frontiers in Marine Science 4 (2017): 332, doi:10.3389/fmars.2017.00332.
    Beschreibung: While sound scattering layers (SSLs) have been described previously from ice-covered waters in the Arctic, the existence of a viable mesopelagic community that also includes mesopelagic fishes in the Arctic has been questioned. In addition, it has been hypothesized that vertical migration would hardly exist in these areas. We wanted to check if deep scattering layers (DSLs) was found to the west and north of Svalbard (79°30′N−82°10′N) during autumn 2015, and if present; whether organisms in such DSLs undertook vertical migrations. Our null hypothesis was that there would be no evidence of diel vertical migration. Multi-frequency acoustic observations by hull mounted echo sounder (18, 38, and 120 kHz) revealed a DSL at depths ~210–510 m in areas with bottom depths exceeding ~600 m. Investigating eight geographical locations that differed with respect to time periods, light cycle and sea ice conditions, we show that the deeper layer of DSL displayed a clear ascending movement during night time and a descending movement during daytime. The high-light weighted mean depth (WMD) (343–514 m) with respect to backscattered energy was statistically deeper than the low-light WMD (179–437 m) for the locations studied. This behavior of the DSL was found to be consistent both when the sun was continuously above the horizon and after it started to set on 1 September, and both in open water and sea ice covered waters. The WMD showed an increasing trend, while the nautical area backscattering strength from the DSL showed a decreasing trend from south to north among the studied locations. Hydrographic observations revealed that the diel migration was found in the lower part of the north-flowing Atlantic Water, and was disconnected from the surface water masses above the Atlantic Water during day and night. The organisms conducting vertical migrations were studied by vertical and oblique hauls with zooplankton nets and pelagic trawls. These data suggest that these organisms were mainly various mesopelagic fishes, some few larger fishes, large zooplankton like krill and amphipods, and various gelatinous forms.
    Beschreibung: The Research Council of Norway is thanked for the financial support through the projects “The Arctic Ocean Ecosystem” — (SI_ARCTIC, RCN 228896), the “Effects of climate change on the Calanus complex”—(ECCO, RCN 200508), “Harvesting marine cold water plankton species—abundance estimation and stock assessment”—(Harvest II, RCN 203871).
    Schlagwort(e): Arctic Ocean ; Deep scattering layer ; Diel vertical migration ; Mesopelagic organisms ; Acoustics
    Repository-Name: Woods Hole Open Access Server
    Materialart: Article
    Standort Signatur Erwartet Verfügbarkeit
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  • 7
    Publikationsdatum: 2022-10-26
    Beschreibung: © The Author(s), 2019. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Capotondi, A., Jacox, M., Bowler, C., Kavanaugh, M., Lehodey, P., Barrie, D., Brodie, S., Chaffron, S., Cheng, W., Dias, D. F., Eveillard, D., Guidi, L., Iudicone, D., Lovenduski, N. S., Nye, J. A., Ortiz, I., Pirhalla, D., Buil, M. P., Saba, V., Sheridan, S., Siedlecki, S., Subramanian, A., de Vargas, C., Di Lorenzo, E., Doney, S. C., Hermann, A. J., Joyce, T., Merrifield, M., Miller, A. J., Not, F., & Pesant, S. Observational needs supporting marine ecosystems modeling and forecasting: from the global ocean to regional and coastal systems. Frontiers in Marine Science, 6, (2019): 623, doi:10.3389/fmars.2019.00623.
    Beschreibung: Many coastal areas host rich marine ecosystems and are also centers of economic activities, including fishing, shipping and recreation. Due to the socioeconomic and ecological importance of these areas, predicting relevant indicators of the ecosystem state on sub-seasonal to interannual timescales is gaining increasing attention. Depending on the application, forecasts may be sought for variables and indicators spanning physics (e.g., sea level, temperature, currents), chemistry (e.g., nutrients, oxygen, pH), and biology (from viruses to top predators). Many components of the marine ecosystem are known to be influenced by leading modes of climate variability, which provide a physical basis for predictability. However, prediction capabilities remain limited by the lack of a clear understanding of the physical and biological processes involved, as well as by insufficient observations for forecast initialization and verification. The situation is further complicated by the influence of climate change on ocean conditions along coastal areas, including sea level rise, increased stratification, and shoaling of oxygen minimum zones. Observations are thus vital to all aspects of marine forecasting: statistical and/or dynamical model development, forecast initialization, and forecast validation, each of which has different observational requirements, which may be also specific to the study region. Here, we use examples from United States (U.S.) coastal applications to identify and describe the key requirements for an observational network that is needed to facilitate improved process understanding, as well as for sustaining operational ecosystem forecasting. We also describe new holistic observational approaches, e.g., approaches based on acoustics, inspired by Tara Oceans or by landscape ecology, which have the potential to support and expand ecosystem modeling and forecasting activities by bridging global and local observations.
    Beschreibung: This study was supported by the NOAA’s Climate Program Office’s Modeling, Analysis, Predictions, and Projections (MAPP) Program through grants NA17OAR4310106, NA17OAR4310104, NA17OAR4310108, NA17OAR4310109, NA17OAR4310110, NA17OAR4310111, NA17OAR4310112, and NA17OAR4310113. This manuscript is a product of the NOAA/MAPP Marine Prediction Task Force. The Tara Oceans consortium acknowledges support from the CNRS Research Federation FR2022 Global Ocean Systems Ecology and Evolution, and OCEANOMICS (grant agreement ‘Investissement d’Avenir’ ANR-11-BTBR-0008). This is article number 95 of the Tara Oceans consortium. MK and SD acknowledge support from NASA grant NNX14AP62A “National Marine Sanctuaries as Sentinel Sites for a Demonstration Marine Biodiversity Observation Network (MBON)” funded under the National Ocean Partnership Program (NOPP RFP NOAA-NOS-IOOS-2014-2003803 in partnership between NOAA, BOEM, and NASA), and the NOAA Integrated Ocean Observing System (IOOS) Program Office. WC, IO, and AH acknowledge partial support from the Joint Institute for the Study of the Atmosphere and Ocean (JISAO) under NOAA Cooperative Agreement NA15OAR4320063, Contribution No. 2019-1029. This study received support from the European H2020 International Cooperation project MESOPP (Mesopelagic Southern Ocean Prey and Predators), grant agreement no. 692173.
    Schlagwort(e): Marine ecosystems ; Modeling and forecasting ; Seascapes ; Genetics ; Acoustics
    Repository-Name: Woods Hole Open Access Server
    Materialart: Article
    Standort Signatur Erwartet Verfügbarkeit
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