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  • 1
    Electronic Resource
    Electronic Resource
    Modeling of mineralogical composition, density and elastic wave velocities in anhydrous magmatic rocks (1994)
    Springer
    Surveys in geophysics 15 (1994), S. 515-544 
    Details
    ISSN: 1573-0956
    Keywords: Petrophysical modeling ; thermodynamic database ; phase diagrams ; elastic properties ; petrologic interpretation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract We use the technique of direct minimization of the Gibbs free energy of the 8-component (K2O-Na2O-Fe2O3-FeO-CaO-MgO-Al2O3-SiO2) multiphase system in order to determine the equilibrium mineral assemblages of rocks of different bulk chemical compositions equilibrated at various P-T conditions. The calculated modal compositions of rocks and experimental data on elastic moduli of single crystals are then used to calculate densities and isotropic elastic wave velocities of rocks together with their pressure and temperature derivatives. Sufficient accuracy of the calculations is confirmed by comparison with experimental data on the gabbro-eclogite transformation and precise ultrasonic measurements of elastic wave velocities in a number of magmatic and metamorphic rocks. We present calculated phase diagrams with isolines of density, elastic wave velocities, and their pressure and temperature derivatives for several anhydrous magmatic rocks, from granite to lherzolite. Density and elastic properties of rocks are controlled by their chemical compositions, especially the SiO2 content, and by P-T of equilibration, and they increase with pressure due to mineral reactions changing mineral assemblages from plagioclase-bearing and garnet-free to garnetbearing and plagioclase-free. TheV p -density correlation is high, and shows two clear trends: one for iron-poor ultramafic rocks and another for all the other rocks considered. Mineral reactions, which occur at high pressures, changeV p and density of anhydrous magmatic rocks following the well-known Birch (or a similar) law. Felsic, intermediate and mafic rocks can be well distinguished in theV p -V p /V s - diagram, although their values ofV p can be close to one another. TheV p -V p /V s -density diagrams together with calculated phase diagrams can serve as efficient instruments for petrologic interpretation of seismic velocities.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00690173
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    Paper (German National Licenses)
    Fulltext
  • 2
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    Controls of the Foreland Deformation Pattern in the Orogen‐Foreland Shortening System: Constraints From High‐Resolution Geodynamic Models (2022)
    Details
    Publication Date: 2022-09-22
    Description: Controls on the deformation pattern (shortening mode and tectonic style) of orogenic forelands during lithospheric shortening remain poorly understood. Here, we use high‐resolution 2D thermomechanical models to demonstrate that orogenic crustal thickness and foreland lithospheric thickness significantly control the shortening mode in the foreland. Pure‐shear shortening occurs when the orogenic crust is not thicker than the foreland crust or thick, but the foreland lithosphere is thin (〈70–80 km, as in the Puna foreland case). Conversely, simple‐shear shortening, characterized by foreland underthrusting beneath the orogen, arises when the orogenic crust is much thicker. This thickened crust results in high gravitational potential energy in the orogen, which triggers the migration of deformation to the foreland under further shortening. Our models present fully thick‐skinned, fully thin‐skinned, and intermediate tectonic styles in the foreland. The first tectonics forms in a pure‐shear shortening mode whereas the others require a simple‐shear mode and the presence of thick (〉∼4 km) sediments that are mechanically weak (friction coefficient 〈∼0.05) or weakened rapidly during deformation. The formation of fully thin‐skinned tectonics in thick and weak foreland sediments, as in the Subandean Ranges, requires the strength of the orogenic upper lithosphere to be less than one‐third as strong as that of the foreland upper lithosphere. Our models successfully reproduce foreland deformation patterns in the Central and Southern Andes and the Laramide province.
    Description: Key Points: Thicknesses of the orogenic crust and the foreland lithosphere control the foreland shortening mode (pure‐shear or simple‐shear). Foreland weak sediments and the upper lithosphere of the weaker orogen control the foreland tectonic style (thin‐skinned or thick‐skinned). High‐resolution geodynamic models successfully reproduce foreland deformation patterns in several natural orogen‐foreland shortening systems.
    Description: Deutsche Forschungsgemeinschaft (DFG) http://dx.doi.org/10.13039/501100001659
    Description: https://bitbucket.org/bkaus/LaMEM
    Description: https://doi.org/10.5281/zenodo.5963016
    Keywords: ddc:551.8
    Language: English
    Type: doc-type:article
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    CITATION GEO-LEO
  • 3
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    Submarine landslides at the eastern Sunda margin: observations and tsunami impact assessment (2010)
    Springer
    In:  Natural Hazards, 54 (2). pp. 547-562.
    Details
    Publication Date: 2019-09-23
    Description: Our analysis of new bathymetric data reveals six submarine landslides at the eastern Sunda margin between central Java and Sumba Island, Indonesia. Their volumes range between 1 km³ in the Java fore-arc basin up to 20 km³ at the trench off Sumba and Sumbawa. We estimate the potential hazard of each event by modeling the corresponding tsunami and its run-up on nearby coasts. Four slides are situated remarkably close to the epicenter of the 1977 tsunamigenic Sumba M w = 8.3 earthquake. However, comparison of documented tsunami run-up heights and arrival times with our modeling results neither allows us to confirm nor can we falsify the hypothesis that the earthquake triggered these submarine landslides.
    Type: Article , PeerReviewed
    Format: text
    DOI: 10.1007/s11069-009-9487-8
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    OceanRep: Article in a Scientific Journal - peer-reviewed
  • 4
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    Impact Forecasting to Support Emergency Management of Natural Hazards (2020)
    AGU (American Geophysical Union) | Wiley
    Details
    Publication Date: 2023-02-08
    Description: Forecasting and early warning systems are important investments to protect lives, properties and livelihood. While early warning systems are frequently used to predict the magnitude, location and timing of potentially damaging events, these systems rarely provide impact estimates, such as the expected amount and distribution of physical damage, human consequences, disruption of services or financial loss. Complementing early warning systems with impact forecasts has a two‐fold advantage: it would provide decision makers with richer information to take informed decisions about emergency measures, and focus the attention of different disciplines on a common target. This would allow capitalizing on synergies between different disciplines and boosting the development of multi‐hazard early warning systems. This review discusses the state‐of‐the‐art in impact forecasting for a wide range of natural hazards. We outline the added value of impact‐based warnings compared to hazard forecasting for the emergency phase, indicate challenges and pitfalls, and synthesize the review results across hazard types most relevant for Europe. Plain language summary Forecasting and early warning systems are important investments to protect lives, properties and livelihood. While such systems are frequently used to predict the magnitude, location and timing of potentially damaging events, they rarely provide impact estimates, such as the expected physical damage, human consequences, disruption of services or financial loss. Extending hazard forecast systems to include impact estimates promises many benefits for the emergency phase, for instance, for organising evacuations. We review and compare the state‐of‐the‐art of impact forcasting across a wide range of natural hazards, and outline opportunities and key challenges for research and development of impact forecasting.
    Type: Article , PeerReviewed , info:eu-repo/semantics/article
    Format: text
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    OceanRep: Article in a Scientific Journal - peer-reviewed
  • 5
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    Controls of the Foreland Deformation Pattern in the Orogen‐Foreland Shortening System: Constraints From High‐Resolution Geodynamic Models (2022)
    AGU (American Geophysical Union) | Wiley
    Details
    Publication Date: 2024-02-07
    Description: Controls on the deformation pattern (shortening mode and tectonic style) of orogenic forelands during lithospheric shortening remain poorly understood. Here, we use high-resolution 2D thermomechanical models to demonstrate that orogenic crustal thickness and foreland lithospheric thickness significantly control the shortening mode in the foreland. Pure-shear shortening occurs when the orogenic crust is not thicker than the foreland crust or thick, but the foreland lithosphere is thin (〈70–80 km, as in the Puna foreland case). Conversely, simple-shear shortening, characterized by foreland underthrusting beneath the orogen, arises when the orogenic crust is much thicker. This thickened crust results in high gravitational potential energy in the orogen, which triggers the migration of deformation to the foreland under further shortening. Our models present fully thick-skinned, fully thin-skinned, and intermediate tectonic styles in the foreland. The first tectonics forms in a pure-shear shortening mode whereas the others require a simple-shear mode and the presence of thick (〉∼4 km) sediments that are mechanically weak (friction coefficient 〈∼0.05) or weakened rapidly during deformation. The formation of fully thin-skinned tectonics in thick and weak foreland sediments, as in the Subandean Ranges, requires the strength of the orogenic upper lithosphere to be less than one-third as strong as that of the foreland upper lithosphere. Our models successfully reproduce foreland deformation patterns in the Central and Southern Andes and the Laramide province.
    Type: Article , PeerReviewed , info:eu-repo/semantics/article
    Format: text
    Format: other
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    OceanRep: Article in a Scientific Journal - peer-reviewed
  • 6
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    Risk workflow for CAScading and COmpounding hazards in COastal urban areas: The CASCO Project (2022)
    Details
    Publication Date: 2024-02-19
    Description: Extreme climatic and geophysical events pose a threat to societies and have the capacity to cause significant damage and losses whenever they occur, both in their immediate aftermath and in the medium- to long-term. Their consequences can be amplified even further when more than one event affects the same geographical areas within a short time. Be it cascading hazards, in which one event triggers the next, or simply hazards that happen to occur simultaneously (“compounding” hazards), estimation of their cumulative consequences is challenging because the action of one event affects the exposure and vulnerability to the next one. While the efforts from the research community to develop multi-hazard perspectives have increased considerably in recent years, multiple remaining challenges require strongly-coordinated efforts across different disciplines and areas of expertise to tackle them with the most appropriate tools. With a multidisciplinary team of scientists from four different Helmholtz research centres in Germany, we have started working on the CASCO project (2022-2024), in which we will develop an integrated risk workflow for CAScading and COmpounding hazards in COastal urban areas by focusing on a series of events occurring around Mount Etna (Italy). The case-scenario starts with a strong earthquake that triggers a submarine collapse at the eastern flank of Mount Etna, an area already known to be unstable, and both the earthquake and the landslide trigger a tsunami that hits the coasts of Sicily and Calabria. Almost concomitantly, a heatwave or heavy rainfall happens to affect the same regions, further stressing the population that had been affected by the combined effects of the earthquake and tsunami. The project will be directed towards the modelling of the cascading earthquake, landslide and tsunami events, the compounding heatwave and rainfall, as well as their immediate impacts in terms of cumulative damage and casualties. Moreover, the medium- to long-term response in urban dynamics and the effect of these extreme events on the economic development of the affected populations will be explored. By focusing on a tangible scenario, CASCO will not only tackle the challenges associated with bringing together the whole risk chain (which will be valid beyond our case-study) but also produce outcomes that help increase awareness of such extreme events and the need for societies to develop suitable strategies to strengthen their resilience and improve their disaster response.
    Type: Conference or Workshop Item , NonPeerReviewed
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    OceanRep: Talk
  • 7
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    The Making of the NEAM Tsunami Hazard Model 2018 (NEAMTHM18) (2021)
    Frontiers
    Details
    Publication Date: 2021-03-08
    Description: The NEAM Tsunami Hazard Model 2018 (NEAMTHM18) is a probabilistic hazard model for tsunamis generated by earthquakes. It covers the coastlines of the North-eastern Atlantic, the Mediterranean, and connected seas (NEAM). NEAMTHM18 was designed as a three-phase project. The first two phases were dedicated to the model development and hazard calculations, following a formalized decision-making process based on a multiple-expert protocol. The third phase was dedicated to documentation and dissemination. The hazard assessment workflow was structured in Steps and Levels. There are four Steps: Step-1) probabilistic earthquake model; Step-2) tsunami generation and modeling in deep water; Step-3) shoaling and inundation; Step-4) hazard aggregation and uncertainty quantification. Each Step includes a different number of Levels. Level-0 always describes the input data; the other Levels describe the intermediate results needed to proceed from one Step to another. Alternative datasets and models were considered in the implementation. The epistemic hazard uncertainty was quantified through an ensemble modeling technique accounting for alternative models’ weights and yielding a distribution of hazard curves represented by the mean and various percentiles. Hazard curves were calculated at 2,343 Points of Interest (POI) distributed at an average spacing of ∼20 km. Precalculated probability maps for five maximum inundation heights (MIH) and hazard intensity maps for five average return periods (ARP) were produced from hazard curves. In the entire NEAM Region, MIHs of several meters are rare but not impossible. Considering a 2% probability of exceedance in 50 years (ARP≈2,475 years), the POIs with MIH 〉5 m are fewer than 1% and are all in the Mediterranean on Libya, Egypt, Cyprus, and Greece coasts. In the North-East Atlantic, POIs with MIH 〉3 m are on the coasts of Mauritania and Gulf of Cadiz. Overall, 30% of the POIs have MIH 〉1 m. NEAMTHM18 results and documentation are available through the TSUMAPS-NEAM project website (http://www.tsumaps-neam.eu/), featuring an interactive web mapper. Although the NEAMTHM18 cannot substitute in-depth analyses at local scales, it represents the first action to start local and more detailed hazard and risk assessments and contributes to designing evacuation maps for tsunami early warning.
    Description: The NEAMTHM18 was prepared in the framework of the European Project TSUMAPS-NEAM (http://www.tsumaps-neam.eu/) funded by the mechanism of the European Civil Protection and Humanitarian Aid Operations with grant no. ECHO/SUB/2015/718568/PREV26 (https://ec.europa.eu/echo/funding-evaluations/financing-civil-protection-europe/selected-projects/probabilistic-tsunami-hazard_en). The work by INGV authors also benefitted from funding by the INGV-DPC Agreement 2012-2021 (Annex B2).
    Description: Published
    Description: 616594
    Description: 6T. Studi di pericolosità sismica e da maremoto
    Description: 1SR TERREMOTI - Sorveglianza Sismica e Allerta Tsunami
    Description: 2SR TERREMOTI - Gestione delle emergenze sismiche e da maremoto
    Description: 3SR TERREMOTI - Attività dei Centri
    Description: 5SR TERREMOTI - Convenzioni derivanti dall'Accordo Quadro decennale INGV-DPC
    Description: 3IT. Calcolo scientifico
    Description: 4IT. Banche dati
    Description: JCR Journal
    Keywords: probabilistic tsunami hazard assessment ; earthquake-generated tsunami ; hazard uncertainty analysis ; ensemble modeling ; maximum inundation height ; NEAM ; 05.08. Risk ; 03.02. Hydrology ; 04.06. Seismology ; 04.07. Tectonophysics ; 05.01. Computational geophysics
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
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    PAPER (OA)
  • 8
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    A New Approximate Method for Quantifying Tsunami Maximum Inundation Height Probability (2019)
    Details
    Publication Date: 2021-06-16
    Description: Regional and global tsunami hazard analysis requires simplified and efficient methods for estimating the tsunami inundation height and its related uncertainty. One such approach is the amplification factor (AF) method. Amplification factors describe the relation between offshore wave height and the maximum inundation height, as predicted by linearized plane wave models employed for incident waves with different wave characteristics. In this study, a new amplification factor method is developed that takes into account the offshore bathymetry proximal to the coastal site. The present AFs cover the North-Eastern Atlantic and Mediterranean (NEAM) region. The model is the first general approximate model that quantifies inundation height uncertainty. Uncertainty quantification is carried out by analyzing the inundation height variability in more than 500 high-resolution inundation simulations at six different coastal sites. The inundation simulations are undertaken with different earthquake sources in order to produce different wave period and polarity. We show that the probability density of the maximum inundation height can be modeled with a log-normal distribution, whose median is quite well predicted by the AF. It is further demonstrated that the associated maximum inundation height uncertainties are significant and must be accounted for in tsunami hazard analysis. The application to the recently developed TSUMAPS-NEAM probabilistic tsunami hazard analysis (PTHA) is presented as a use case.
    Description: Published
    Description: 3227–3246
    Description: 6T. Studi di pericolosità sismica e da maremoto
    Description: JCR Journal
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
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    PAPER (OA)
  • 9
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    Effect of Shallow Slip Amplification Uncertainty on Probabilistic Tsunami Hazard Analysis in Subduction Zones: Use of Long-Term Balanced Stochastic Slip Models (2020)
    Springer
    Details
    Publication Date: 2021-04-20
    Description: The complexity of coseismic slip distributions influences the tsunami hazard posed by local and, to a certain extent, distant tsunami sources. Large slip concentrated in shallow patches was observed in recent tsunamigenic earthquakes, possibly due to dynamic amplification near the free surface, variable frictional conditions or other factors. We propose a method for incorporating enhanced shallow slip for subduction earthquakes while preventing systematic slip excess at shallow depths over one or more seismic cycles. The method uses the classic k−2 stochastic slip distributions, augmented by shallow slip amplification. It is necessary for deep events with lower slip to occur more often than shallow ones with amplified slip to balance the long-term cumulative slip. We evaluate the impact of this approach on tsunami hazard in the central and eastern Mediterranean Sea adopting a realistic 3D geometry for three subduction zones, by using it to model ~ 150,000 earthquakes with 𝑀𝑤 from 6.0 to 9.0. We combine earthquake rates, depth-dependent slip distributions, tsunami modeling, and epistemic uncertainty through an ensemble modeling technique. We found that the mean hazard curves obtained with our method show enhanced probabilities for larger inundation heights as compared to the curves derived from depth-independent slip distributions. Our approach is completely general and can be applied to any subduction zone in the world.
    Description: Published
    Description: 1497–1520
    Description: 3T. Sorgente sismica
    Description: 6T. Studi di pericolosità sismica e da maremoto
    Description: JCR Journal
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
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  • 10
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    Probabilistic Tsunami Hazard Analysis: High Performance Computing for Massive Scale Inundation Simulations (2021)
    Frontiers
    Details
    Publication Date: 2021-01-14
    Description: Probabilistic Tsunami Hazard Analysis (PTHA) quantifies the probability of exceeding a specified inundation intensity at a given location within a given time interval. PTHA provides scientific guidance for tsunami risk analysis and risk management, including coastal planning and early warning. Explicit computation of site-specific PTHA, with an adequate discretization of source scenarios combined with high-resolution numerical inundation modelling, has been out of reach with existing models and computing capabilities, with tens to hundreds of thousands of moderately intensive numerical simulations being required for exhaustive uncertainty quantification. In recent years, more efficient GPU-based High-Performance Computing (HPC) facilities, together with efficient GPU-optimized shallow water type models for simulating tsunami inundation, have now made local long-term hazard assessment feasible. A workflow has been developed with three main stages: 1) Site-specific source selection and discretization, 2) Efficient numerical inundation simulation for each scenario using the GPU-based Tsunami-HySEA numerical tsunami propagation and inundation model using a system of nested topo-bathymetric grids, and 3) Hazard aggregation. We apply this site-specific PTHA workflow here to Catania, Sicily, for tsunamigenic earthquake sources in the Mediterranean. We illustrate the workflows of the PTHA as implemented for High-Performance Computing applications, including preliminary simulations carried out on intermediate scale GPU clusters. We show how the local hazard analysis conducted here produces a more fine-grained assessment than is possible with a regional assessment. However, the new local PTHA indicates somewhat lower probabilities of exceedance for higher maximum inundation heights than the available regional PTHA. The local hazard analysis takes into account small-scale tsunami inundation features and non-linearity which the regional-scale assessment does not incorporate. However, the deterministic inundation simulations neglect some uncertainties stemming from the simplified source treatment and tsunami modelling that are embedded in the regional stochastic approach to inundation height estimation. Further research is needed to quantify the uncertainty associated with numerical inundation modelling and to properly propagate it onto the hazard results, to fully exploit the potential of site-specific hazard assessment based on massive simulations.
    Description: Published
    Description: 591549
    Description: 6T. Studi di pericolosità sismica e da maremoto
    Description: JCR Journal
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
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