1,720,984 research outputs found
Can simple magnitude-dependent 2D Gaussian representations of co-seismic slip distributions improve real time tsunami simulations?
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Landslide-tsunamis along the flanks of Mount Epomeo, Ischia: propagation patterns and coastal hazard for the Campania Coasts, Italy
No full textIschia Island has been repeatedly affected by mass collapses, which are mainly caused by the steepness of the main peak (Mt Epomeo) and by phenomena related to its volcanic activity. The most relevant cases of mass failure studied in the literature and postulated to be tsunamigenic cover a wide spectrum of sizes, from sector collapse to small-volume mass transports. Tsunamis generated by landslides in Ischia may affect the coast of the Campania mainland, including the Gulf of Naples. The focus of this work is an evaluation of the pattern of the maximum tsunami energy. To this purpose, we perform a series of numerical simulations by moving the same landslide source in different hypothetical positions around the island. The landslide dynamics are computed through the code UBO-BLOCK, and the tsunami propagation by employing the code UBO-TSUFD, both developed in-house. The final goal is to characterize the coastal areas of the Campania mainland most exposed to tsunami attack from Ischia sources. It is found that the position of the landslide deeply influences the distribution of the tsunami elevation in the coastal stretch north of the Procida Mt, while, remarkably, it is irrelevant inside the Gulf of Naples where the bathymetric effect prevails
APPLICABILITY OF 2D GAUSSIAN SLIP DISTRIBUTIONS TO REPRESENT REALISTIC CO- SEISMIC SLIP HETEROGENEITIES: CONSEQUENCES FOR TSUNAMI MODELLING AND EARLY WARNING
No full textModelling a Composite Tsunami Scenario for Karpathos Island (Aegean Sea)
No full textKarpathos is one of the biggest Greek islands, located between Crete and Rhodes in Aegean Sea. As the most of the islands in the area Karpathos is prone to earthquakes and tsunamis. The event of 9 February 1948 (M 7.1) near the eastern coast of the island caused local tsunami with damages in the area of Pigadia bay, nevertheless tsunamis also from regional sources are expected. The tsunami hazard for the Karpathos Island, focusing on the city of Karpathos and the Airport area, is modelled merging the data from simulation of tsunamis generated by three seismic sources: Eastern Hellenic Arc (EHA referring the 1303 A.D. event, Mw = 8.0); near Rhodes (hypothetical scenario earthquake, Mw = 7.3); and near the coast of Karpathos, based on the 1948, Mw = 7.3 earthquake. Numerical calculations are made using the code UBO-TSUFD on a set of nested grids. Tsunami observables, such as maximal water column height, maximum velocity flux, inundation, are computed for each individual scenario and merged to individuate the areas most exposed to tsunami. The seismic source EHA dominates in the tsunami hazard maps: moreover, the impact over the southern part of Karpathos has biggest risk since the airport and the main city of the island are located in this part
Aggregated Tsunami Scenario for Karpathos Island
No full textKarpathos is the second largest of the Greek Dodecanese islands. Historical data such as the event of 9 February 1948, indicate that this area is prone to earthquakes and tsunamis. In this study we evaluate the tsunami hazard for the Karpathos Island by means of a scenario-based technique. We take into account tsunamis generated by three main seismic sources in agreement with local tectonics and historical records. The code UBO-TSUFD is used for all numerical simulations. Tsunamis are computed in several domains with different resolution for a better calculation of the maximum coastal wave height and tsunami inundation. Tsunami parameters for each individual scenario are used to construct a unique aggregated scenario, which help us to evaluate the inundation zone. The contribution of all scenarios along the coast of Karpathos is studied via synthetic mareograms. It is found that EHA dominates and that the southern Karpathos is more exposed to tsunamis
An improved workflow to efficiently compute local seismic probabilistic tsunami analysis (SPTHA): a case study for the harbour of Ravenna, Italy
No full textAn improved workflow to efficiently compute local seismic probabilistic tsunami analysis (SPTHA): a case study for the harbour of Ravenna, Italy
No full textRisk Assessment Methodology for Cascading Earthquake and Tsunami Impact Applied to the Town of Augusta (Eastern Sicily, Italy)
No full textThe AD 365 Crete Earthquake/Tsunami Submarine Impact on the Mediterranean Region
Full text linkThe Calabrian and Hellenic subduction systems accommodate the African Eurasian plate convergence in the Mediterranean Sea and are the site of large earthquakes in the forearc region facing the northern African coasts. Some of the historical earthquakes were associated with the generation of tsunami waves affecting the entire Mediterranean basin. We investigated the submarine effects of the AD 365 Crete earthquake on the sedimentary records through the integrated analysis of geophysical data, turbidite deposits, and tsunami modelling. Seismic reflection images show that some turbidite beds are thick and marked by acoustic transparent layers at their top. Radiometric dating of the most recent of such mega-beds, the Homogenite/Augias turbidite (HAT), provide evidence for synchronous basin-wide sedimentation during a catastrophic event which has occurred in the time window of AD 364–415, consistent with the AD 365 Mw = 8.3–8.5 Crete earthquake/tsunamis. The HAT (up to 25 m thick) contains components from different sources, implying remobilization of material from areas very far from the epicentre. Utilizing the expanded stratigraphy of the HAT and the heterogeneity of the sediment sources of the Mediterranean margins, we reconstructed the relative contribution of the Italian, Maltan and African margins to the turbidite deposition. Our sedimentological reconstructions combined with tsunami modelling suggest that the tsunami following the Crete earthquake produced giant turbidity currents along a front over 2000 km long, from northern Africa to Italy. Our cores suggests that during the last 15,000 years, only two similar turbidites have been deposited in the deep basins, pointing to a large recurrence time of such extreme sedimentary events
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