scholarly journals Insights on the Small Tsunami from 28 January 2020 Caribbean Sea MW7.7 Earthquake by Numerical Simulation and Spectral Analysis

2021 ◽  
Author(s):  
Zhiguo Xu ◽  
Lining Sun ◽  
Mohd Nashriq Abd Rahman ◽  
Shanshan Liang ◽  
Jianyu Shi ◽  
...  
Keyword(s):  
Spectral Analysis ◽  
High Frequency ◽  
Tide Gauge ◽  
Caribbean Sea ◽  
Strike Slip ◽  
Submarine Landslide ◽  
Small Scale ◽  
Tsunami Simulation ◽  
Finite Fault ◽  
Simulation Results

Abstract A huge left-lateral strike-slip Mw7.7 earthquake struck the Caribbean Sea on January 28, 2020. Thus, a small tsunami was generated as as result of the earthquake. The information and observational data gathered for the earthquake and tsunami, as well as integrating the regional tectonic setting, were used to describe the seismogenic source’s properties. The COMCOT model was used for tsunami simulation, with Okada’s dislocation model from finite fault solutions for MW7.7 Caribbean Sea earthquake published by the USGS. The simulation results were compare to tide gauge records to validate whether the seafloor vertical displacements generated by strike-slip fault caused a small tsunami. We conduct spectral analysis of tsunami to better understand the characteristics of tsunami records. Tsunami simulation results show that the coseismic vertical displacement caused by a strike-slip MW7.7 earthquake can contribute to the small tsunami, and the anomalously large high-frequency tsunami waves recorded by the George tide gauge in 11 minutes after the earthquake were unrelated to the earthquake-generated tsunami. According to spectrum analysis. The predominant period of the noticeable high frequency tsunami wave recorded by George tide gauge is only 2 minutes. This indicates that the source of small tsunami was close to the George station and travelled a distance of ~ 150 km, indicating a submarine landslide caused by the strike-slip earthquake. The comprehensive analysis shows that the small-scale tsunami was not caused solely by coseismic seafloor deformation from this strike-slip event, but that earthquake-triggered submarine landslide was the primary cause. Hence, the combined effect of two sources leads to the small-scale tsunami.

scholarly journals Deep submarine landslide contribution to the 2010 Haiti earthquake tsunami

2020 ◽  
Vol 20 (7) ◽  
pp. 2055-2065
Author(s):  
Adrien Poupardin ◽  
Eric Calais ◽  
Philippe Heinrich ◽  
Hélène Hébert ◽  
Mathieu Rodriguez ◽  
...  
Keyword(s):  
Slope Failure ◽  
Tide Gauge ◽  
Strike Slip ◽  
Submarine Landslide ◽  
Secondary Source ◽  
Submarine Landslides ◽  
Haiti Earthquake ◽  
Southern Coast ◽  
Ground Acceleration ◽  
The North

Abstract. The devastating Mw 7.1 Haiti earthquake in 2010 was accompanied by local tsunamis that caused fatalities and damage to coastal infrastructure. Some were triggered by slope failures of river deltas in the close vicinity of the epicenter, while others, 30 to 50 km to the north across the Bay of Gonâve, are well explained by the reverse component of coseismic ground motion that accompanied this mostly strike-slip event. However, observations of run-up heights up to 2 m along the southern coast of the island at distances up to 100 km from the epicenter, as well as tide gauge and DART buoy records at distances up to 600 km from the epicenter, have not yet received an explanation. Here we demonstrate that these observations require a secondary source, most likely a submarine landslide. We identify a landslide scar 30 km from the epicenter off the southern coast of Haiti at a depth of 3500 m, where ground acceleration would have been sufficient to trigger slope failure in soft sediments. This candidate source, 2 km3 in volume, matches observations remarkably well assuming that the sediment collapse obeys a viscous flow with an initial apparent viscosity of 2×105 Pa s. Although that particular source cannot be proven to have been activated in 2010, our results add to a line of evidence that earthquake-triggered submarine landslides can cause significant tsunamis in areas of strike-slip tectonic regime.

scholarly journals Deep Submarine Landslide Contribution to the 2010 Haiti Earthquake Tsunami

2020 ◽  
Author(s):  
Adrien Poupardin ◽  
Eric Calais ◽  
Philippe Heinrich ◽  
Hélène Hébert ◽  
Mathieu Rodriguez ◽  
...  
Keyword(s):  
Slope Failure ◽  
Tide Gauge ◽  
Strike Slip ◽  
Submarine Landslide ◽  
Secondary Source ◽  
Submarine Landslides ◽  
Haiti Earthquake ◽  
Southern Coast ◽  
Ground Acceleration ◽  
The North

Abstract. The devastating Mw 7, 2010, Haiti earthquake was accompanied by local tsunamis that caused fatalities and damage to coastal infrastructure. Some were triggered by slope failures of river deltas in close vicinity of the epicenter, while others, 30 to 50 km to the north across the Bay of Gonâve, are well explained by the reverse component of coseismic ground motion that accompanied this mostly strike-slip event. However, observations of run-up heights up to 2 m along the southern coast of the island at distances up to 100 km from the epicenter, as well as tide gauge and DART buoy records at distances up to 600 km from the epicenter have not yet received an explanation. Here we demonstrate that these observations require a secondary source, most likely a submarine landslide. We identify a landslide scar 30 km from the epicenter off the southern coast of Haiti at a depth of 3500 m, where ground acceleration would have been sufficient to trigger slope failure in soft sediments. This candidate source, 2 km3 in volume, matches observation remarkably well assuming that the sediment collapse obeys a viscous flow with an initial apparent viscosity of 2 × 105 Pa s. Although that particular source cannot be proven to have been activated in 2010, our results add to a line of evidence that earthquake-triggered submarine landslides can cause significant tsunamis in areas of strike-slip tectonic regime.

Numerical Study of Methane and Air Combustion Inside Heat-Recirculating Combustors

2013 ◽  
Author(s):  
Yanxia Li ◽  
Zhongliang Liu ◽  
Yan Wang ◽  
Jiaming Liu
Keyword(s):  
Gas Flow ◽  
Numerical Study ◽  
Convection Heat Transfer ◽  
Central Area ◽  
Small Scale ◽  
Inlet Velocity ◽  
Strong Convection ◽  
Simulation Results ◽  
Lean Fuel ◽  
Set Up

A numerical model on methane/air combustion inside a small Swiss-roll combustor was set up to investigate the flame position of small-scale combustion. The simulation results show that the combustion flame could be maintained in the central area of the combustor only when the speed and equivalence ratio are all within a narrow and specific range. For high inlet velocity, the combustion could be sustained stably even with a very lean fuel and the flame always stayed at the first corner of reactant channel because of the strong convection heat transfer and preheating. For low inlet velocity, small amounts of fuel could combust stably in the central area of the combustor, because heat was appropriately transferred from the gas to the inlet mixture. Whereas, for the low premixed gas flow, only in certain conditions (Φ = 0.8 ～ 1.2 when ν0 = 1.0m/s, Φ = 1.0 when ν0 = 0.5m/s) the small-scale combustion could be maintained.

Finite Element Simulation of Laser Beam Welding Induced Residual Stresses and Distortions in a T-Joint Configuration for Aeronautic Structures

2009 ◽  
Author(s):  
Muhammad Zain-ul-abdein ◽  
Daniel Ne´lias ◽  
Jean-Franc¸ois Jullien ◽  
Dominique Deloison
Keyword(s):  
Finite Element ◽  
Residual Stresses ◽  
Laser Beam ◽  
Boundary Conditions ◽  
Laser Beam Welding ◽  
Temperature Fields ◽  
Heat Transfer Analysis ◽  
Small Scale ◽  
Joint Configuration ◽  
Simulation Results

Laser beam welding has found its application in the aircraft industry for the fabrication of fuselage panels in a T-joint configuration. However, the inconveniences like distortions and residual stresses are inevitable consequences of welding. The effort is made in this work to experimentally measure and numerically simulate the distortions induced by laser beam welding of a T-joint with industrially used thermal and mechanical boundary conditions on the thin sheets of aluminium 6056-T4. Several small scale experiments were carried out with various instrumentations to establish a database necessary to verify the simulation results. Finite element (FE) simulation is performed with Abaqus and the conical heat source is programmed in FORTRAN. Heat transfer analysis is performed to achieve the required weld pool geometry and temperature fields. Mechanical analysis is then performed with industrial loading and boundary conditions so as to predict the distortion and the residual stress pattern. A good agreement is found amongst the experimental and simulation results.

Characteristics of Heat Transfer and Flow on a Surface With Small-Scale Concave Spherical Pits

2008 ◽  
Author(s):  
J. S. Wang ◽  
Y. Qiu ◽  
L. Y. Li
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Small Scale ◽  
Heat Transfer Mechanism ◽  
Transfer Enhancement ◽  
Special Effect ◽  
Turbulent Drag Reduction ◽  
Turbulent Drag ◽  
Simulation Results ◽  
Turbulent Coherent Structure

Small-scale concave spherical pits, which have a special effect on heat transfer enhancement and turbulent drag reduction, are investigated by numerical simulation in detail. Two kinds of small-scale concave pits structures are designed on surface of a plate, which are located in the bottom of a rectangle channel. The characteristics of heat transfer and flow in channel are investigated and compared with a same channel with plate bottom by means of LES. Flow structure and temperature distribution near the pits are analyzed. The numerical simulation results indicate that the concave spherical pits disturb the flow field and vortex is induced by the pits. The turbulent coherent structure is affected by the induced vortex. The numerical simulation indicates that small scale pit can generate the vortex in couple. The range of vortex is accord with the array of small scale pit. The small scale pit can enhance the intensity of vortex. As a result, the temperature field near the pit is changed with generation of the vortex. The heat transfer mechanism on plate with small scale concave spherical pit is summarized.

Microearthquake seismicity and tectonics of Coastal Northern California

1970 ◽  
Vol 60 (5) ◽  
pp. 1669-1699 ◽  
Author(s):  
Leonardo Seeber ◽  
Muawia Barazangi ◽  
Ali Nowroozi
Keyword(s):  
High Frequency ◽  
Fault Plane ◽  
San Andreas Fault ◽  
High Gain ◽  
Strike Slip ◽  
Fault System ◽  
Northern California ◽  
Fault Plane Solutions ◽  
Sharp Bend ◽  
San Andreas

Abstract This paper demonstrates that high-gain, high-frequency portable seismographs operated for short intervals can provide unique data on the details of the current tectonic activity in a very small area. Five high-frequency, high-gain seismographs were operated at 25 sites along the coast of northern California during the summer of 1968. Eighty per cent of 160 microearthquakes located in the Cape Mendocino area occurred at depths between 15 and 35 km in a well-defined, horizontal seismic layer. These depths are significantly greater than those reported for other areas along the San Andreas fault system in California. Many of the earthquakes of the Cape Mendocino area occurred in sequences that have approximately the same magnitude versus length of faulting characteristics as other California earthquakes. Consistent first-motion directions are recorded from microearthquakes located within suitably chosen subdivisions of the active area. Composite fault plane solutions indicate that right-lateral movement prevails on strike-slip faults that radiate from Cape Mendocino northwest toward the Gorda basin. This is evidence that the Gorda basin is undergoing internal deformation. Inland, east of Cape Mendocino, a significant component of thrust faulting prevails for all the composite fault plane solutions. Thrusting is predominant in the fault plane solution of the June 26 1968 earthquake located along the Gorda escarpement. In general, the pattern of slip is consistent with a north-south crustal shortening. The Gorda escarpment, the Mattole River Valley, and the 1906 fault break northwest of Shelter Cove define a sharp bend that forms a possible connection between the Mendocino escarpment and the San Andreas fault. The distribution of hypocenters, relative travel times of P waves, and focal mechanisms strongly indicate that the above three features are surface expressions of an important structural boundary. The sharp bend in this boundary, which is concave toward the southwest, would tend to lock the dextral slip along the San Andreas fault and thus cause the regional north-south compression observed at Cape Mendocino. The above conclusions support the hypothesis that dextral strike-slip motion along the San Andreas fault is currently being taken up by slip along the Mendocino escarpment as well as by slip along northwest trending faults in the Gorda basin.

Precambrian tectonic evolution of Earth: an outline

2021 ◽  
Vol 124 (1) ◽  
pp. 141-162 ◽  
Author(s):  
J.F. Dewey ◽  
E.S. Kiseeva ◽  
J.A. Pearce ◽  
L.J. Robb
Keyword(s):  
Tectonic Evolution ◽  
Plate Tectonics ◽  
Global Scale ◽  
Sensu Stricto ◽  
Strike Slip ◽  
Small Scale ◽  
Data Sets ◽  
Crustal Material ◽  
Plate Tectonic ◽  
Single Plate

Abstract Space probes in our solar system have examined all bodies larger than about 400 km in diameter and shown that Earth is the only silicate planet with extant plate tectonics sensu stricto. Venus and Earth are about the same size at 12 000 km diameter, and close in density at 5 200 and 5 500 kg.m-3 respectively. Venus and Mars are stagnant lid planets; Mars may have had plate tectonics and Venus may have had alternating ca. 0.5 Ga periods of stagnant lid punctuated by short periods of plate turnover. In this paper, we contend that Earth has seen five, distinct, tectonic periods characterized by mainly different rock associations and patterns with rapid transitions between them; the Hadean to ca. 4.0 Ga, the Eo- and Palaeoarchaean to ca. 3.1 Ga, the Neoarchaean to ca. 2.5 Ga, the Proterozoic to ca. 0.8 Ga, and the Neoproterozoic and Phanerozoic. Plate tectonics sensu stricto, as we know it for present-day Earth, was operating during the Neoproterozoic and Phanerozoic, as witnessed by features such as obducted supra-subduction zone ophiolites, blueschists, jadeite, ruby, continental thin sediment sheets, continental shelf, edge, and rise assemblages, collisional sutures, and long strike-slip faults with large displacements. From rock associations and structures, nothing resembling plate tectonics operated prior to ca. 2.5 Ga. Archaean geology is almost wholly dissimilar from Proterozoic-Phanerozoic geology. Most of the Proterozoic operated in a plate tectonic milieu but, during the Archaean, Earth behaved in a non-plate tectonic way and was probably characterised by a stagnant lid with heat-loss by pluming and volcanism, together with diapiric inversion of tonalite-trondjemite-granodiorite (TTG) basement diapirs through sinking keels of greenstone supracrustals, and very minor mobilism. The Palaeoarchaean differed from the Neoarchaean in having a more blobby appearance whereas a crude linearity is typical of the Neoarchaean. The Hadean was probably a dry stagnant lid Earth with the bulk of its water delivered during the late heavy bombardment, when that thin mafic lithosphere was fragmented to sink into the asthenosphere and generate the copious TTG Ancient Grey Gneisses (AGG). During the Archaean, a stagnant unsegmented, lithospheric lid characterised Earth, although a case can be made for some form of mobilism with “block jostling”, rifting, compression and strike-slip faulting on a small scale. We conclude, following Burke and Dewey (1973), that there is no evidence for subduction on a global scale before about 2.5 Ga, although there is geochemical evidence for some form of local recycling of crustal material into the mantle during that period. After 2.5 Ga, linear/curvilinear deformation belts were developed, which “weld” cratons together and palaeomagnetism indicates that large, lateral, relative motions among continents had begun by at least 1.88 Ga. The “boring billion”, from about 1.8 to 0.8 Ga, was a period of two super-continents (Nuna, also known as Columbia, and Rodinia) characterised by substantial magmatism of intraplate type leading to the hypothesis that Earth had reverted to a single plate planet over this period; however, orogens with marginal accretionary tectonics and related magmatism and ore genesis indicate that plate tectonics was still taking place at and beyond the bounds of these supercontinents. The break-up of Rodinia heralded modern plate tectonics from about 0.8 Ga. Our conclusions are based, almost wholly, upon geological data sets, including petrology, ore geology and geochemistry, with minor input from modelling and theory.

Estimating contribution of high-frequency sea-level oscillations to the extreme sea levels in the Adriatic Sea

2021 ◽  
Author(s):  
Krešimir Ruić ◽  
Jadranka Šepić ◽  
Maja Karlović ◽  
Iva Međugorac
Keyword(s):  
Time Series ◽  
Sea Level ◽  
High Frequency ◽  
Adriatic Sea ◽  
Tide Gauge ◽  
Data Series ◽  
Sea Levels ◽  
Short Period ◽  
Extreme Sea Levels ◽  
Sea Level Oscillations

<p>Extreme sea levels are known to hit the Adriatic Sea and to occasionally cause floods that produce severe material damage. Whereas the contribution of longer-period (T > 2 h) sea-level oscillations to the phenomena has been well researched, the contribution of the shorter period (T < 2 h) oscillations is yet to be determined. With this aim, data of 1-min sampling resolution were collected for 20 tide gauges, 10 located at the Italian (north and west) and 10 at the Croatian (east) Adriatic coast. Analyses were done on time series of 3 to 15 years length, with the latest data coming from 2020, and with longer data series available for the Croatian coast. Sea level data were thoroughly checked, and spurious data were removed. </p><p>For each station, extreme sea levels were defined as events during which sea level surpasses its 99.9 percentile value. The contribution of short-period oscillations to extremes was then estimated from corresponding high-frequency (T < 2 h) series. Additionally, for four Croatian tide gauge stations (Rovinj, Bakar, Split, and Dubrovnik), for period of 1956-2004, extreme sea levels were also determined from the hourly sea level time series, with the contribution of short-period oscillations visually estimated from the original tide gauge charts.  </p><p>Spatial and temporal distribution of contribution of short-period sea-level oscillations to the extreme sea level in the Adriatic were estimated. It was shown that short-period sea-level oscillation can significantly contribute to the overall extremes and should be considered when estimating flooding levels. </p>

Deep and Shallow Water Low-Speed Maneuvering Tests: Comparison Between Experimental and Simulation Results

2016 ◽  
Author(s):  
Felipe Ribolla Masetti ◽  
Pedro Cardozo de Mello ◽  
Guilherme F. Rosetti ◽  
Eduardo A. Tannuri
Keyword(s):  
Mathematical Model ◽  
Small Scale ◽  
Shallow Waters ◽  
Hydrodynamic Coefficients ◽  
Low Speed ◽  
Tunnel Model ◽  
Oceanographic Research ◽  
Simulation Results ◽  
The University ◽  
The Mathematical Model

This paper presents small-scale low-speed maneuvering tests with an oceanographic research vessel and the comparison with mathematical model using the real time maneuvering simulator developed by the University of São Paulo (USP). The tests are intended to verify the behavior of the vessel and the mathematical model under transient and low speed tests. The small-scale tests were conducted in deep and shallow waters, with a depth-draft ratio equal to 1.28, in order to verify the simulator ability to represent the vessel maneuverability on both depth conditions. The hydrodynamic coefficients used in the simulator model were obtained by CFD calculations and wind tunnel model tests carried out for this vessel. Standard turning circle and accelerating turn maneuvers were used to compare the experimental and numerical results. A fair agreement was achieved for shallow and deep water. Some differences were observed mainly in the initial phase of the accelerating turn test.

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