Challenges and Potential of Waveform Modeling for Crustal Scale Predictions.

Calibration of the Regional Crustal Waveguide and the Retrieval of Source Parameters Using Waveform Modeling

Monitoring the Comprehensive Nuclear-Test-Ban Treaty: Regional Wave Propagation and Crustal Structure ◽

10.1007/978-3-0348-8262-0_9 ◽

2001 ◽

pp. 1301-1338

Author(s):

Chandan K. Saikia ◽

Bradley B. Woods ◽

H. K. Thio

Keyword(s):

Source Parameters ◽

Waveform Modeling

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HYDRODYNAMIC AND BOUSSINESQ WAVE MODELING FOR THE N219 AMPHIBIOUS AIRCRAFT SEAPLANE DOCK DEVELOPMENT PLAN IN PANJANG ISLAND

Majalah ilmiah Pengkajian Industri ◽

10.29122/mipi.v15i2.4769 ◽

2021 ◽

Vol 15 (2) ◽

Author(s):

Hanah Khoirunnisa ◽

Mardi Wibowo ◽

Wahyu Hendriyono ◽

Khusnul Setia Wardani

Keyword(s):

Flight Test ◽

The Other ◽

Waveform Modeling ◽

Significant Wave ◽

Other Hand ◽

Wave Heights ◽

Significant Wave Heights ◽

Wave Conditions ◽

The Difference ◽

Mike 21

The flight test of N219 Amphibious aircraft will be targeted in 2003/2024. For flight tests, these aircraft need a seaplane dock. One of the potential locations for the seaplane dock is Panjang Island at Seribu Islands. This study aims to know the characteristic of hydrodynamic and wave conditions and to determine whether Panjang Island is suitable for the seaplane dock. This study uses a modeling method with MIKE 21 FM HD-SW module and MIKE 21 Boussinesq Wave (BW) module. The bathymetry data were obtained from the Indonesian Navy Hydrographic and Oceanographic Center (Pushidrosal), tide data is generated from Tide Model Driver (TMD), wave and wind data from ECMWF. The result of surface elevation validation between hydrodynamic modeling and TMD is 92%. During the west monsoon and spring conditions, the difference in the largest and lowest current velocity is quite large (0.018-0.199 m/s), on the other hand, when the tides are in neap conditions (0.008-0.144 m/s). Meanwhile, during the east monsoon and spring conditions, the difference in the largest and lowest current velocities is quite large (0.02-0.193 m/s), on the other hand, when the tides are in neap conditions (0.008-0.146 m/s). The maximum wave height resulting from the 50-year return period waveform modeling between 1.139 - 1.474 m. Meanwhile, the significant wave heights between 0.679 - 0.741 with a significant wave period of 13.45 seconds. In general, the current and wave conditions of the two locations are suitable for the construction of the seaplane dock, except that the dominant wave heights are still above the requirements.

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Fault reactivation by gas injection at an underground gas storage off the east coast of Spain

10.5194/se-2019-113 ◽

2019 ◽

Author(s):

Antonio Villaseñor ◽

Robert B. Herrmann ◽

Beatriz Gaite ◽

Arantza Ugalde

Keyword(s):

East Coast ◽

Fault Plane ◽

Source Parameters ◽

Gas Injection ◽

Focal Depth ◽

Gas Storage ◽

Fault Reactivation ◽

Underground Gas Storage ◽

Waveform Modeling ◽

Valencia Trough

Abstract. During September–October of 2013 an intense swarm of earthquakes occurred off the east coast of Spain associated with the injection of the base gas in an offshore underground gas storage. Two weeks after the end of the injection operations, three moderate-sized earthquakes (Mw 4.0–4.1) occurred near the storage. These events were widely felt by the nearby population, leading to the indefinite shut-down of the facility. Here we investigate the source parameters (focal depth and mechanism) of the largest earthquakes in the sequence in order to identify the faults reactivated by the gas injection, and to help understand the processes that caused the earthquakes. Our waveform modeling results indicate that the largest earthquakes occurred at depths of 6–8 km beneath the sea floor, significantly deeper than the injection depth (~ 1800 m). Although we cannot undoubtedly discriminate the fault plane from the two nodal planes of the mechanisms, most evidence seems to favor a NW-SE striking fault plane. We propose that the gas injection reactivated unmapped faults in the Paleozoic basement, with regional orientation possibly inherited from the opening of the Valencia Trough.

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Anisotropy in the oceanic lithosphere from the study of local intraplate earthquakes on the west flank of the southern East Pacific Rise: Shear wave splitting and waveform modeling

Journal of Geophysical Research Atmospheres ◽

10.1029/1999jb900046 ◽

1999 ◽

Vol 104 (B5) ◽

pp. 10695-10717 ◽

Cited By ~ 10

Author(s):

Shu-Huei Hung ◽

Donald W. Forsyth

Keyword(s):

Shear Wave ◽

East Pacific Rise ◽

Oceanic Lithosphere ◽

Shear Wave Splitting ◽

The West ◽

Intraplate Earthquakes ◽

Waveform Modeling ◽

East Pacific ◽

Wave Splitting

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Modeling teleseismic SV waves from underground explosions with tectonic release: Results for Southern Novaya Zemlya

Bulletin of the Seismological Society of America ◽

10.1785/bssa0780031158 ◽

1988 ◽

Vol 78 (3) ◽

pp. 1158-1178

Author(s):

Brian P. Cohee ◽

Thorne Lay

Keyword(s):

Source Region ◽

Test Site ◽

Strike Slip ◽

Destructive Interference ◽

Ray Theory ◽

Source Strength ◽

Sh Waves ◽

Waveform Modeling ◽

Novaya Zemlya ◽

Double Couple

Abstract Detailed forward modeling of long-period shear waves for two large underground explosions at the Southern Novaya Zemlya test site indicates that the appropriate equivalent double-couple orientation for the tectonic release radiation is vertical strike-slip. Previous studies of observed teleseismic SH waveforms and SV amplitudes for the 27 October 1973 and 2 November 1974 events using geometric ray theory could not distinguish between vertical strike-slip and 45°-dipping thrust geometries. Either mechanism can match the observed four-lobed SH radiation pattern, and the two-lobed SV amplitude pattern can be produced by interference with an appropriate size explosion pS signal. However, the complexity of the observed SV waveforms arising from Sp conversions near the receiver, diffracted Sp, and shear-coupled PL phases is not accounted for in the ray theory synthetics. Incorporating more realistic Green's functions using Baag and Langston's (1985b) WKBJ spectral method allows more complete modeling of the SV signals. Due to differences in frequency content between the explosion and double-couple SV waveforms, constructive interference occurs more efficiently than destructive interference when the two signals are linearly superimposed. As a result, using tectonic release moments determined from the SH waves and the optimum F factors required to match the SV amplitude patterns, the waveforms produced by the strike-slip and thrust orientations differ substantially at some azimuths. The strike-slip solution yields a consistently superior match to the data. Using the EU2 model of Lerner-Lam and Jordan (1987) for the source region and either EU2 or TNA (Grand and Helmberger, 1984) for the receiver structure, together with an attenuation model similar to SL8, we obtain a double-couple moment, M0 = 3.2 × 1024 dyne-cm and explosion source strength, ψ∞ = 3.8 ± 0.5 × 1011 cm3 for the 27 October 1973 event, and M0 = 1.7 × 1024 dyne-cm and ψ∞ = 2.0 ± 0.3 × 1011 cm3 for the 2 November 1974 event. Complete waveform modeling of SV signals can thus provide improved constraints on tectonic release radiation and explosion source strength.

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Waveform modeling of the November 1987 Superstition Hills earthquakes

Bulletin of the Seismological Society of America ◽

10.1785/bssa0790020500 ◽

1989 ◽

Vol 79 (2) ◽

pp. 500-514 ◽

Cited By ~ 2

Author(s):

Allison L. Bent ◽

Donald V. Helmberger ◽

Richard J. Stead ◽

Phyllis Ho-Liu

Keyword(s):

Body Wave ◽

Source Parameters ◽

Strong Motion ◽

Source Depth ◽

Strong Motion Data ◽

Waveform Modeling ◽

Motion Data ◽

Teleseismic Data ◽

Slip Event ◽

Double Event

Abstract Long-period body-wave data recorded at teleseismic distances and strong-motion data at Pasadena for the Superstition Hills earthquakes of 24 November 1987 are modeled to obtain the source parameters. We will refer to the event that occurred at 0153 UT as EQ1 and the event at 1316 UT as EQ2. At all distances the first earthquake appears to be a simple left-lateral strike-slip event on a fault striking NE. It is a relatively deep event with a source depth of 10 km. It has a teleseismic moment of 2.7 ×1025 dyne cm. The second and more complex event was modeled in two ways: by using EQ1 as the Green's function and by using a more traditional forward modeling technique to create synthetic seismograms. The first method indicated that EQ2 was a double event with both subevents similar, but not identical to EQ1 and separated by about 7.5 sec. From the synthetic seismogram study we obtained a strike of 305° for the first subevent and 320° for the second. Both have dips of 80° and rakes of 175°. The first subevent has a moment of 3.6 ×1025 which is half that of the second. We obtain depths of at least 6 km. The teleseismic data indicate a preferred subevent separation of 30 km with the second almost due south of the first, but the error bounds are substantial. This would suggest that the subevents occurred on conjugate faults. The strong-motion data at PAS, however, imply a much smaller source separation, with the sources probably produced by asperities.

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