Seismotectonics of the Horseshoe Abyssal Plain and Gorringe Bank, eastern Atlantic Ocean: Constraints from ocean bottom seismometer data

Grevemeyer, Ingo; Lange, Dietrich; Villinger, Heinrich; Custódio, Susana; Matias, L.

doi:10.1002/2016jb013586

Cited by 16 publications

(7 citation statements)

References 73 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In this methodological work, we considered a widened AGPB tsunamigenic area and we chose to explore as largely as possible 2 | Summary of the variation range of the seismic source input parameters for the design, the western, the eastern database and for the tsunami scenarios associated to the Gorringe bank and the Horseshoe bank (hypothesis from Duarte et al, 2013;Grevemeyer et al, 2017). Magnitude range M w [-] 6.7 -9.3 6.7 -8.3 6.8 -9.3 7.7 -8.9 7.7 -8.9 6.7 -9.3 *Seismic source parameters are assumed uniformly distributed and are randomly sampled for the construction of the Global database.…”

Section: Numerical Tool and Design Data-basementioning

confidence: 99%

“…In order to illustrate how to integrate the evaluation of uncertainties in a MCS approach, we focus on two specific and nearly deterministic scenarios considered as likely sources generating the Lisbon 1755 tsunami, namely the Gorringe and Horseshoe structures (Buforn et al, 1988;Stich et al, 2007;Cunha et al, 2012;Duarte et al, 2013;Grevemeyer et al, 2017). Both structures were modeled taking into account available maps (Cunha et al, 2012;Duarte et al, 2013) and fault parameters (Stich et al, 2007;Grevemeyer et al, 2017) summarized in Table 2. For the computation of the tsunami heights associated with these scenarios, fault parameters are considered uniformly distributed and are randomly sampled in their range of variation ( Table 2), for a total of nearly 10,000 tsunami scenarios.…”

Section: Potential Application Of Meta-models For Tsunami Hazard Analmentioning

confidence: 99%

See 1 more Smart Citation

Using Meta-Models for Tsunami Hazard Analysis: An Example of Application for the French Atlantic Coast

Bacchi¹,

Jomard²,

Scotti³

et al. 2020

Front. Earth Sci.

View full text Add to dashboard Cite

This paper illustrates how an emulator (or meta-model) of a tsunami code can be a useful tool to evaluate or qualify tsunami hazard levels associated with both specific and unknown tsunamigenic seismic sources. The meta-models are statistical tools permitting to drastically reduce the computational time necessary for tsunami simulations. As a consequence they can be used to explore the tsunamigenic potential of a seismic zone, by taking into account an extended set of tsunami scenarios. We illustrate these concepts by studying the tsunamis generated by the Azores-Gibraltar Plate Boundary (AGPB) and potentially impacting the French Atlantic Coast. We first analyze the impact of two realistic scenarios corresponding to potential sources of the 1755-Lisbon tsunami (when uncertainty on seismic parameters is considered). We then show how meta-models could permit to qualify the tsunamis generated by this seismic area. All the results are finally discussed in light of tsunami hazard issued by the TSUMAPS-NEAM research project available online (http://ai2lab.org/tsumapsneam/ interactive-hazard-curve-tool/). From this methodological study, it appears that tsunami hazard issued by TSUMAPS-NEAM research project is envelop, even when compared to all the likely and unlikely tsunami scenarios generated in the AGPB area. Abbreviations: µ, shear modulus; [N(m(x), s 2 (x))], Gaussian process of mean "m(x)" and variance "s 2 (x)"; [M(x)], kriging surrogate; {X,Y}, are the coordinates of the design simulations used for kriging parameters evaluation; C(.), covariance kernel; CEA, commissariat à l'énergie atomique et aux énergies alternatives; D [m], average slip along the rupture surface; DTHA, deterministic tsunami hazard assessment; GSA, global sensitivity analysis; L [m], length of the rupture surface; MCS, maximum credible scenario; MCS_h, tsunami hazard level issued by an exploration of a very wide range of tsunamigenic scenarios; M o , seismic moment; M w , seismic moment magnitude; MSE, mean squared error; PTHA, probabilistic tsunami hazard assessment; R 2 , squared correlation coefficient; RMSE, root mean squared error; UQ, uncertainty quantifications; W [m], width of the rupture surface.

show abstract

Section: Numerical Tool and Design Data-basementioning

confidence: 99%

Section: Potential Application Of Meta-models For Tsunami Hazard Analmentioning

confidence: 99%

Using Meta-Models for Tsunami Hazard Analysis: An Example of Application for the French Atlantic Coast

Bacchi¹,

Jomard²,

Scotti³

et al. 2020

Front. Earth Sci.

View full text Add to dashboard Cite

show abstract

“…Four works with heat flow values in the area were published by three different teams (Bullard and Day, 1961;Verzhbitsky and Zolotarev, 1989;Grevemeyer et al, 2009;Grevemeyer et al, 2017)…”

Section: Introductionmentioning

confidence: 99%

The Deep South Portuguese Margin: An Attempt to Account for Heat Flow Density Variation in this Region

Duque¹

2022

ijthfa

View full text Add to dashboard Cite

Heat flow data measured in a region characterized by a very high and non-uniform thickness (accretionary prism) of sediments, traversed by strike-slip faults in the E-W direction and thrust faults in the N-S direction, were analyzed. Mud volcanoes have been discovered in the region during the last 20 years. The region includes parts of the borders between the Eurasian and the African plates, at SW of the Iberian Peninsula. Sediment porosity and vertical fluid movements were inferred from thermal conductivity and thermal gradient data. Fault location and boundary of the sediment prism were used to test the results inferred and to explain the scatter in the published heat flow values. Special attention was given to values obtained in regions separating different geologic settings (Gorringe Bank – Horseshoe Plain and Marquês de Pombal fault region). Geoid height values were used to obtain information related with heat flow values from deep parts of the Horseshoe plain and in the Gorringe Bank located in the western part of the region studied outside the accretionary prism of sediments. Information related with the evolution of some transient properties in the region were obtained from geoid height variations using three models made for three different years. Information about the thermal disturbance caused by fluid movements in the region and the heat flow values without them were obtained at the end of the work.

show abstract

“…In spite of the current low tectonic convergence rate, the study area exhibits remarkable levels of seismic activity, both onshore and offshore. Current studies, based on data recorded both on land and on the seafloor, indicate that earthquakes occur either in thickened, normal or thinned continental crust, as well as in the oceanic crust and lithospheric uppermost mantle (Custódio et al 2015;Grevemeyer et al 2015Grevemeyer et al , 2016Grevemeyer et al , 2017Veludo et al 2017;Silva et al 2017). A reliable 3-D P-and S-wave speed model of both the crust and upper mantle is therefore needed for accurate seismic wave propagation and geodynamic modelling.…”

Section: Introductionmentioning

confidence: 99%

PRISM3D: a 3-D reference seismic model for Iberia and adjacent areas

Arroucau

Custódio

Civiero

et al. 2021

Geophysical Journal International

View full text Add to dashboard Cite

SUMMARY We present PRISM3D, a 3-D reference seismic model of P- and S-wave velocities for Iberia and adjacent areas. PRISM3D results from the combination of the most up-to-date earth models available for the region. It extends horizontally from 15°W to 5°E in longitude, 34°N to 46°N in latitude and vertically from 3.5 km above to 200 km below sea level, and is modelled on a regular grid with 10 and 0.5 km of grid node spacing in the horizontal and vertical directions, respectively. It was designed using models inferred from local and teleseismic body-wave tomography, earthquake and ambient noise surface wave tomography, receiver function analysis and active source experiments. It includes two interfaces, namely the topography/bathymetry and the Mohorovičić (Moho) discontinuity. The Moho was modelled from previously published receiver function analysis and deep seismic sounding results. To that end we used a probabilistic surface reconstruction algorithm that allowed to extract the mean of the Moho depth surface along with its associated standard deviation, which provides a depth uncertainty estimate. The Moho depth model is in good agreement with previously published models, although it presents slightly sharper gardients in orogenic areas such as the Pyrenees or the Betic-Rif system. Crustal and mantle P- and S-wave wave speed grids were built separately on each side of the Moho depth surface by weighted average of existing models, thus allowing to realistically render the speed gradients across that interface. The associated weighted standard deviation was also calculated, which provides an uncertainty estimation on the average wave speed values at any point of the grid. At shallow depths (<10 km), low P and S wave speeds and high VP/VS are observed in offshore basins, while the Iberian Massif, which covers a large part of western Iberia, appears characterized by a rather flat Moho, higher than average VP and VS and low VP/VS. Conversely, the Betic-Rif system seems to be associated with low VP and VS, combined with high VP/VS in comparison to the rest of the study area. The most prominent feature of the mantle is the well known high wave speed anomaly related to the Alboran slab imaged in various mantle tomography studies. The consistency of PRISM3D with previous work is verified by comparing it with two recent studies, with which it shows a good general agreement.The impact of the new 3-D model is illustrated through a simple synthetic experiment, which shows that the lateral variations of the wave speed can produce traveltime differences ranging from –1.5 and 1.5 s for P waves and from –2.5 and 2.5 s for S waves at local to regional distances. Such values are far larger than phase picking uncertainties and would likely affect earthquake hypocentral parameter estimations. The new 3-D model thus provides a basis for regional studies including earthquake source studies, Earth structure investigations and geodynamic modelling of Iberia and its surroundings.

show abstract

Seismotectonics of the Horseshoe Abyssal Plain and Gorringe Bank, eastern Atlantic Ocean: Constraints from ocean bottom seismometer data

Cited by 16 publications

References 73 publications

Using Meta-Models for Tsunami Hazard Analysis: An Example of Application for the French Atlantic Coast

Using Meta-Models for Tsunami Hazard Analysis: An Example of Application for the French Atlantic Coast

The Deep South Portuguese Margin: An Attempt to Account for Heat Flow Density Variation in this Region

PRISM3D: a 3-D reference seismic model for Iberia and adjacent areas

Contact Info

Product

Resources

About