Deformation and Tsunami Inundation estimates from published slip distributions: How reliable are they?

Mapping Intimacies ◽

10.5194/egusphere-egu2020-1613 ◽

2020 ◽

Author(s):

Jochen Woessner ◽

Rozita Jalali Farahani

Keyword(s):

Elastic Deformation ◽

Initial Conditions ◽

Fault Slip ◽

Tsunami Hazard ◽

Seismic Survey ◽

Dislocation Model ◽

Deformation Model ◽

Tsunami Inundation ◽

Finite Fault ◽

Hazard And Risk

A series of large subduction interface earthquakes along the South American coast caused large tsunamis in recent years. Each of these events, such as the 2010 Mw8.8 Maule and the 2015 Mw8.3 Illapel events, provided novel insights to improve tsunami hazard and risk modeling for the region, in particular due to the amount of data collected during post-seismic/ tsunami surveys reporting on coastal deformation, tsunami inundation, and building stock damage. These data are genuinely relevant to evaluate scenario modeling results supporting general approaches to model the tsunami hazard and risk.Despite the usefulness of rapidly determined finite-fault slip inversions for tsunami warning systems, the reliability of calculated elastic deformations along the coastline based on these models and subsequently tsunami flow depth and runup estimates might be questionable. We primarily shed light on the possible impact of using various solutions for selected historical events by performing full tsunami scenario calculation. We evaluate the inverted slip model solutions from the perspective of a tsunami modeler, i.e. we compare results of the elastic deformation modelling to observed coastal uplift and tsunami inundation against post-seismic survey data. These are important as coastal deformation strongly affects tsunami inundation results. Secondly, we compare observed data to modeled data from inverted slip distributions to solutions based on simulated slip distributions on the same fault geometries to understand the possible range of outcomes. .Given an inverted slip distribution, we first map those onto the Slab2.0 subduction interface and then calculate stochastic slip distributions. Thereafter, vertical seafloor/coastline deformations are computed using a triangular elastic dislocation model that captures the complexities of the subduction zone geometry. The deformations serve as initial conditions to a high-resolution numerical model that simulates the tsunami wave propagation and coastal inundations. Parallel computations are applied to overcome the large numerical computational efforts needed. Variable land surface roughness based on land cover data is used to simulate the accurate hydraulics of coastal inundation.Based on our modelling approach, we find that some published slip inversion models are deficient in modelling observed coastal deformation using an elastic deformation model. Only when including tsunami data for the inversions, these models tend to be better constrained. Without these data, finite fault slip inversions for local tsunami forecasts might be misleading in spatial inundation estimates as deformation results may be incorrect. This can happen both ways, either underestimating or overestimating tsunami inundations. While there are many additional aspects in the tsunami modelling procedure, this is an important basic aspect.Our results show that simulating stochastic slip distributions enables to cover the range of possible deformation and inundation results well. This result underlines that this approach is a useful tool to generate local probabilistic tsunami hazard and risk models.

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Present-day orogenic processes in the western Kalpin nappe explored by interseismic GNSS measurements and coseismic InSAR observations of the 2020 Mw 6.1 Kalpin event

Geophysical Journal International ◽

10.1093/gji/ggab097 ◽

2021 ◽

Author(s):

Ping He ◽

Yangmao Wen ◽

Shuiping Li ◽

Kaihua Ding ◽

Zhicai Li ◽

...

Keyword(s):

Source Parameters ◽

Satellite System ◽

Tien Shan ◽

Dislocation Model ◽

Maximum Displacement ◽

Finite Fault ◽

Instantaneous Deformation ◽

Gnss Measurements ◽

Global Navigation Satellite ◽

Finite Fault Model

Summary As the largest and most active intracontinental orogenic belt on Earth, the Tien Shan (TS) is a natural laboratory for understanding the Cenozoic orogenic processes driven by the India-Asia collision. On 19 January 2020, a Mw 6.1 event stuck the Kalpin region, where the southern frontal TS interacts with the Tarim basin. To probe the local ongoing orogenic processes and potential seismic hazard in the Kalpin region, both interseismic and instantaneous deformation derived from geodetic observations are employed in this study. With the constraint of interseismic global navigation satellite system (GNSS) velocities, we estimate the décollement plane parameters of the western Kalpin nappe based on a two-dimensional dislocation model, and the results suggest that the décollement plane is nearly subhorizontal with a dip of ∼3° at a depth of 24 km. Then, we collect both Sentinel-1 and ALOS-2 satellite images to capture the coseismic displacements caused by the 2020 Kalpin event, and the interferometric synthetic aperture radar (InSAR) images show a maximum displacement of 7 cm in the line of sight near the epicentral region. With these coseismic displacement measurements, we invert the source parameters of this event using a finite-fault model. We determine the optimal source mechanism in which the fault geometry is dominated by thrust faulting with an E–W strike of 275° and a northward dip of 11.2°, and the main rupture slip is concentrated within an area 28.0 km in length and${\rm{\,\,}}$10.3 km in width, with a maximum slip of 0.3 m at a depth of 6–8 km. The total released moment of our preferred distributed slip model yields a geodetic moment of 1.59 × 1018 N$\cdot $m, equivalent to Mw 6.1. The contrast of the décollement plane depth from interseismic GNSS and the rupture depth from coseismic InSAR suggests that a compression still exists in the Kalpin nappe forefront, which is prone to frequent moderate events and may be at risk of a much more dangerous earthquake.

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Hydrodynamic Model of Transport System

East European Journal of Physics ◽

10.26565/2312-4334-2020-1-11 ◽

2020 ◽

Keyword(s):

Hydrodynamic Model ◽

Transition Period ◽

Initial Conditions ◽

Flow Line ◽

Conveyor Belt ◽

Deformation Model ◽

Longitudinal Vibrations ◽

Production Flow ◽

Dynamic Stresses ◽

Transportation Route

A hydrodynamic model of production systems with a flow method of organizing production is considered. The basic macro-parameters of the state of the production flow line and the relationship between them are determined. The choice of a lot of moment approximation for modelling the production line is justified. It is shown that the conveyor-type flow line is a complex dynamic system with distributed parameters. The boundary value problem is formulated for the longitudinal vibrations of the conveyor belt when the material moves along the transportation route. It is assumed that there is no sliding of material along the conveyor belt, and the deformation that occurs in the conveyor belt is proportional to the applied force (Hooke's elastic deformation model). The significant effect of the uneven distribution of the material along the transportation route on the propagation velocity of dynamic stresses in the conveyor belt is shown. When constructing the boundary and initial conditions, the recommendations of DIN 22101: 2002-08 were used. The mechanism of the occurrence of longitudinal vibrations of the conveyor belt when the material moves along the transportation route is investigated. The main parameters of the model that cause dynamic stresses are determined. It is shown that dynamic stresses are formed as a result of a superposition of stresses in the direct and reflected waves. Analytical expressions are written that make it possible to calculate the magnitude of dynamic stresses in a conveyor belt and determine the conditions for the occurrence of destruction of the conveyor belt. The characteristic phases of the initial movement of the material along the technological route are considered. The process of the emergence of dynamic stresses with the constant and variable acceleration of the conveyor belt is investigated. The dynamics of stress distribution along the transportation route is presented. It is shown that the value of dynamic stresses can exceed the maximum permissible value, which leads to the destruction of the conveyor belt or structural elements. The transition period is estimated, which is required to ensure a trouble-free mode of transport operation during acceleration or braking of the conveyor belt. The use of dimensionless parameters allows us to formulate criteria for the similarity of conveyor systems.

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The Euro-Mediterranean Tsunami Catalogue

Annals of Geophysics ◽

10.4401/ag-6437 ◽

2014 ◽

Vol 57 (4) ◽

Author(s):

Alessandra Maramai ◽

Beatriz Brizuela ◽

Laura Graziani

Keyword(s):

High Reliability ◽

Tsunami Hazard ◽

Historical Documents ◽

Complex Task ◽

Detailed Review ◽

Additional Information ◽

Documentary Sources ◽

Hazard And Risk ◽

Hazard And Risk Assessment

A unified catalogue containing 290 tsunamis generated in the European and Mediterranean seas since 6150 B.C. to current days is presented. It is the result of a systematic and detailed review of all the regional catalogues available in literature covering the study area, each of them having their own format and level of accuracy. The realization of a single catalogue covering a so wide area and involving several countries was a complex task that posed a series of challenges, being the standardization and the quality of the data the most demanding. A “reliability” value was used to rate equally the quality of the data for each event and this parameter was assigned based on the trustworthiness of the information related to the generating cause, the tsunami description accuracy and also on the availability of coeval bibliographical sources. Following these criteria we included in the catalogue events whose reliability ranges from 0 (“very improbable tsunami”) to 4 (“definite tsunami”). About 900 documentary sources, including historical documents, books, scientific reports, newspapers and previous catalogues, support the tsunami data and descriptions gathered in this catalogue. As a result, in the present paper a list of the 290 tsunamis with their main parameters is reported. The online version of the catalogue, available at http://roma2.rm.ingv.it/en/facilities/data_bases/52/catalogue_of_the_euro-mediterranean_tsunamis, provides additional information such as detailed descriptions, pictures, etc. and the complete list of bibliographical sources. Most of the included events have a high reliability value (3= “probable” and 4= “definite”) which makes the Euro-Mediterranean Tsunami Catalogue an essential tool for the implementation of tsunami hazard and risk assessment.

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Case study: mapping the tsunami-hazard zone in the Pasir Jambak sub-district, in Padang, Indonesia

E3S Web of Conferences ◽

10.1051/e3sconf/202133104006 ◽

2021 ◽

Vol 331 ◽

pp. 04006

Author(s):

Leli Honesti ◽

Meli Muchlian

Keyword(s):

Large Scale ◽

Grid Point ◽

Tsunami Hazard ◽

Decision Makers ◽

Tsunami Inundation ◽

Tsunami Risk ◽

Nested Grid ◽

Inundation Map ◽

Run Up

A tsunami hazard is an adverse event that causes damage to properties and loss of life. The problem in assessing a tsunami risk zone for a small area is significant, as available tsunami inundation zone data does not give detailed information for tsunami inundation and run-up in every nested grid. Hence, this study aims to establish a tsunami risk map in the Pasir Jambak sub-district, Padang, Indonesia. The map was carried out in every nested grid point of the area and on a large scale (1:5,000). The TUNAMI N3 program was used for the simulation of the tsunami inundation. A tsunami assessment was made through simulations in nine scenarios of fault parameter data for Sipora block earthquakes. The result of the study provides a tsunami inundation map. Furthermore, this tsunami inundation map can be used for communities, local authorities, government, and others for many studies, and decision-makers can come up with mitigation plans for a small study area.

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Probabilistic Tsunami Hazard and Risk Analysis: A Review of Research Gaps

Frontiers in Earth Science ◽

10.3389/feart.2021.628772 ◽

2021 ◽

Vol 9 ◽

Author(s):

Jörn Behrens ◽

Finn Løvholt ◽

Fatemeh Jalayer ◽

Stefano Lorito ◽

Mario A. Salgado-Gálvez ◽

...

Keyword(s):

Risk Analysis ◽

Hazard Analysis ◽

Tsunami Hazard ◽

Future Research ◽

Extensive Literature ◽

Research Gaps ◽

Earthquake Sources ◽

Hazard And Risk ◽

Probabilistic Tsunami Hazard Analysis ◽

Hazard And Risk Analysis

Tsunamis are unpredictable and infrequent but potentially large impact natural disasters. To prepare, mitigate and prevent losses from tsunamis, probabilistic hazard and risk analysis methods have been developed and have proved useful. However, large gaps and uncertainties still exist and many steps in the assessment methods lack information, theoretical foundation, or commonly accepted methods. Moreover, applied methods have very different levels of maturity, from already advanced probabilistic tsunami hazard analysis for earthquake sources, to less mature probabilistic risk analysis. In this review we give an overview of the current state of probabilistic tsunami hazard and risk analysis. Identifying research gaps, we offer suggestions for future research directions. An extensive literature list allows for branching into diverse aspects of this scientific approach.

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3D linked megathrust, dynamic rupture and tsunami propagation and inundation modeling: Dynamic effects of supershear and tsunami earthquakes

10.5194/egusphere-egu21-15257 ◽

2021 ◽

Author(s):

Sara Aniko Wirp ◽

Alice-Agnes Gabriel ◽

Elizabeth H. Madden ◽

Maximilian Schmeller ◽

Iris van Zelst ◽

...

Keyword(s):

Subduction Zones ◽

Large Scale ◽

Dynamic Models ◽

Initial Conditions ◽

Poisson Ratio ◽

Fault Slip ◽

Moment Magnitude ◽

Dynamic Rupture ◽

S Wave ◽

Tsunami Propagation

Earthquake rupture dynamic models capture the variability of slip in space and time while accounting for the structural complexity which is characteristic for subduction zones. The use of a geodynamic subduction and seismic cycling (SC) model to initialize dynamic rupture (DR) ensures that initial conditions are self-consistent and reflect long-term behavior. We extend the 2D geodynamical subduction and SC model of van Zelst et al. (2019) and use it as input for realistic 3-dimensional DR megathrust earthquake models. We follow the subduction to tsunami run-up linking approach described in Madden et al. (2020), including a complex subduction setup along with their resulting tsunamis. The distinct variation of shear traction and friction coefficients with depth lead to realistic average rupture speeds and dynamic stress drop as well as efficient tsunami generation.&#160;We here analyze a total of 14 subduction-initialized 3D dynamic rupture-tsunami scenarios. By varying the hypocentral location along arc and depth, we generate 12 distinct unilateral and bilateral earthquakes with depth-variable slip distribution and directivity, bimaterial, and geometrical effects in the dynamic slip evolutions. While depth variations of the hypocenters barely influence the tsunami behavior, lateral varying nucleation locations lead to a shift in the on-fault slip which causes time delays of the wave arrival at the coast. The fault geometry of our DR model that arises during the SC model is non-planar and includes large-scale roughness. These features (topographic highs) trigger supershear rupture propagation in up-dip or down-dip direction, depending on the hypocentral depth.In two additional scenarios, we analyze variations in the energy budget of the DR scenarios. In the SC model, an incompressible medium is assumed (&#957;=0.5) which is valid only for small changes in pressure and temperature. Unlike in the DR model where the material is compressible and a different Poisson&#8217;s ratio (&#957;=0.25) has to be assigned. Poisson&#8217;s ratios between 0.1 and 0.4 stand for various compressible materials. To achieve a lower shear strength of all material on and off the megathrust fault and to facilitate slip, we increase the Poisson ratio in the DR model to &#957;=0.3 which is consistent with basaltic rocks. As a result, larger fault slip is concentrated at shallower depths and generates higher vertical seafloor displacement and earthquake moment magnitude respectively. Even though the tsunami amplitudes are much higher, the same dynamic behavior as in the twelve hypocenter-variable models can be observed. Lastly, we increase fracture energy by changing the critical slip distance in the linear slip-weakening frictional parameterization. This generates a tsunami earthquake (Kanamori, 1972) characterized by low rupture velocity (on average half the amount of s-wave speed) and low peak slip rate, but at the same time large shallow fault slip and moment magnitude. The shallow fault slip of this event causes the highest vertical seafloor uplift compared to all other simulations. This leads to the highest tsunami amplitude and inundation area while the wavefront hits the coast delayed compared to the other scenarios.

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Material removal characteristics of precorroded Lu2O3 laser crystals and elastic deformation model during nanoscratch process

Tribology International ◽

10.1016/j.triboint.2019.106027 ◽

2020 ◽

Vol 143 ◽

pp. 106027 ◽

Cited By ~ 2

Author(s):

Shuohua Zhang ◽

Xiaoguang Guo ◽

Zhuji Jin ◽

Renke Kang ◽

Dongming Guo

Keyword(s):

Elastic Deformation ◽

Material Removal ◽

Deformation Model ◽

Laser Crystals

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Tsunami hazard and risk assessment for Alexandria (Egypt) based on the maximum credible earthquake

Journal of African Earth Sciences ◽

10.1016/j.jafrearsci.2019.103735 ◽

2020 ◽

Vol 162 ◽

pp. 103735 ◽

Cited By ~ 2

Author(s):

Hany M. Hassan ◽

C. Frischknecht ◽

Mohamed N. ElGabry ◽

Hesham Hussein ◽

Mona ElWazir

Keyword(s):

Risk Assessment ◽

Tsunami Hazard ◽

Maximum Credible Earthquake ◽

Hazard And Risk ◽

Hazard And Risk Assessment

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Development of an inversion method to extract information on fault geometry from teleseismic data

Geophysical Journal International ◽

10.1093/gji/ggz496 ◽

2019 ◽

Vol 220 (2) ◽

pp. 1055-1065 ◽

Cited By ~ 3

Author(s):

Kousuke Shimizu ◽

Yuji Yagi ◽

Ryo Okuwaki ◽

Yukitoshi Fukahata

Keyword(s):

Fault Plane ◽

Slip Rate ◽

Rate Function ◽

Fault Slip ◽

Body Waves ◽

Fault System ◽

Inversion Method ◽

Fault Geometry ◽

Finite Fault ◽

Extract Information

SUMMARY Teleseismic waveforms contain information on fault slip evolution during an earthquake, as well as on the fault geometry. A linear finite-fault inversion method is a tool for solving the slip-rate function distribution under an assumption of fault geometry as a single or multiple-fault-plane model. An inappropriate assumption of fault geometry would tend to distort the solution due to Green’s function modelling errors. We developed a new inversion method to extract information on fault geometry along with the slip-rate function from observed teleseismic waveforms. In this method, as in most previous studies, we assumed a flat fault plane, but we allowed arbitrary directions of slip not necessarily parallel to the assumed fault plane. More precisely, the method represents fault slip on the assumed fault by the superposition of five basis components of potency-density tensor, which can express arbitrary fault slip that occurs underground. We tested the developed method by applying it to real teleseismic P waveforms of the MW 7.7 2013 Balochistan, Pakistan, earthquake, which is thought to have occurred along a curved fault system. The obtained spatiotemporal distribution of potency-density tensors showed that the focal mechanism at each source knot was dominated by a strike-slip component with successive strike angle rotation from 205° to 240° as the rupture propagated unilaterally towards the south-west from the epicentre. This result is consistent with Earth’s surface deformation observed in optical satellite images. The success of the developed method is attributable to the fact that teleseismic body waves are not very sensitive to the spatial location of fault slip, whereas they are very sensitive to the direction of fault slip. The method may be a powerful tool to extract information on fault geometry along with the slip-rate function without requiring detailed assumptions about fault geometry.

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