Acoustic Pressure, Particle Motion, and Induced Ground Motion Signals from a Commercial Seismic Survey Array and Potential Implications for Environmental Monitoring

An experimental marine seismic source survey off the northwest Australian coast operated a 2600 cubic inch (41.6 l) airgun array, every 5.88 s, along six lines at a northern site and eight lines at a southern site. The airgun array was discharged 27,770 times with 128,313 pressure signals, 38,907 three-axis particle motion signals, and 17,832 ground motion signals recorded. Pressure and ground motion were accurately measured at horizontal ranges from 12 m. Particle motion signals saturated out to 1500 m horizontal range (50% of signals saturated at 230 and 590 m at the northern and southern sites, respectively). For unsaturated signals, sound exposure levels (SEL) correlated with measures of sound pressure level and water particle acceleration (r2= 0.88 to 0.95 at northern site and 0.97 at southern) and ground acceleration (r2= 0.60 and 0.87, northern and southern sites, respectively). The effective array source level was modelled at 247 dB re 1µPa m peak-to-peak, 231 dB re 1 µPa2 m mean-square, and 228 dB re 1 µPa2∙m2 s SEL at 15° below the horizontal. Propagation loss ranged from −29 to −30log10 (range) at the northern site and −29 to −38log10(range) at the southern site, for pressure measures. These high propagation losses are due to near-surface limestone in the seabed of the North West Shelf.

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Strong ground motion of mine tremors: Some implications for near-source ground motion parameters

Bulletin of the Seismological Society of America ◽

10.1785/bssa0710010295 ◽

1981 ◽

Vol 71 (1) ◽

pp. 295-319

Author(s):

A. McGarr ◽

R. W. E. Green ◽

S. M. Spottiswoode

Keyword(s):

Ground Motion ◽

Source Parameters ◽

Seismic Source ◽

Shear Velocity ◽

Recording System ◽

Ground Acceleration ◽

Hypocentral Distance ◽

Earthquake Size ◽

Mine Tremors ◽

Stress Drops

abstract Ground acceleration was recorded at a depth of about 3 km in the East Rand Proprietary Mines, South Africa, for tremors with −1 ≦ ML ≦ 2.6 in the hypocentral distance range 50 m < R ≦ 1.6 km. The accelerograms typically had predominant frequencies of several hundred Hertz and peak accelerations, a, as high as 12 g. The peak accelerations show a dependence on magnitude, especially when expressed as dynamic shear-stress differences, defined as σ˜ = ρRa, where ρ is density. For the mine tremors, σ˜ varies from 2 to 500 bars and depends on magnitude according to log σ˜ = 1.40 + 0.38 · ML. Accelerograms for 12 events were digitized and then processed to determine velocity and, for seven events with especially good S/N, displacement and seismic source parameters. Peak ground velocities v ranged up to 6 cm/sec and show a well-defined dependence one earthquake size as measured by ML or by seismic moment, Mo. On the basis of regression fits to the mine data, with −0.76 ≦ ML ≦ 1.45, log Rv = 3.95 + 0.57 ML, where Rv is in cm2/sec, and log Rv = −4.68 + 0.49 log Mo. These regression lines agree excellently with the corresponding data for earthquakes of ML up to 6.4 or Mo to 1.4 × 1026 dyne-cm. At a given value of ML or Mo, a, at fixed R, shows considerably greater variation than v and appears to depend on the bandwidth of the recording system. The peak acceleration at small hypocentral distances is broadly consistent with ρRa = 1.14 Δτrofs/β, where Δτ is stress drop, ro is the source radius, β is shear velocity, and fs is the bandwidth of the recording system. The peak velocity data agree well with Rv = 0.57 βΔτro/μ, where μ is the modulus of rigidity; both expressions follow from Brune's model of the seismic source and were compared with data for events in the size range 5 × 1016 ≦ Mo ≦ 1.4 × 1026 dyne-cm. Measurements of the source parameters indicated that, as for earthquakes, the stress drops for the tremors range from 1 to 100 bars and show no consistent dependence on Mo down to Mo = 5 × 1016 dyne-cm.

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A New Method for the Realistic Estimation of Seismic Ground Motion in Megacities: The Case of Rome

Earthquake Spectra ◽

10.1193/1.1585735 ◽

1993 ◽

Vol 9 (4) ◽

pp. 643-668 ◽

Cited By ~ 44

Author(s):

Donat Fäh ◽

Claudio Iodice ◽

Peter Suhadolc ◽

Guilano F. Panza

Keyword(s):

Total Energy ◽

Ground Motion ◽

Sedimentary Basins ◽

Radial Component ◽

Hybrid Technique ◽

Ground Acceleration ◽

Near Surface ◽

Local Soil ◽

Soil Effects ◽

Rigid Material

A hybrid technique, based on mode summation and finite differences, is used to simulate the ground motion induced in the city of Rome by the January 13, 1915, Fucino (Italy) earthquake (ML=6.8). The technique allows us to take into consideration source, path, and local soil effects. The results of the numerical simulations are used for a comparison between the observed distribution of damage in Rome, and the computed peak ground acceleration, the maximum response of simple oscillators, and the so-called “total energy of ground motion”. The total energy of ground motion is in good agreement with the observed distribution of damage. From the computation of spectral ratios, it has been recognized that the presence of a near-surface layer of rigid material is not sufficient to classify a location as a “hard-rock site” when the rigid material has a sedimentary complex below it. This is because the underlying sedimentary complex causes amplifications due to resonances. Within sedimentary basins, incident energy in certain frequency bands can also be shifted from the vertical, into the radial component of motion. This phenomenon is very localized, both in frequency and space, and closely neighboring sites can be characterized by large differences in the seismic response.

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Site Characterization Using Microtremor Array and Seismic Hazard Assessment for Jakarta, Indonesia

Bulletin of the Seismological Society of America ◽

10.1785/0120190040 ◽

2019 ◽

Vol 109 (6) ◽

pp. 2644-2657 ◽

Cited By ~ 1

Author(s):

Mohamad Ridwan ◽

Phil R. Cummins ◽

Sri Widiyantoro ◽

Masyhur Irsyam

Keyword(s):

Seismic Hazard ◽

Ground Motion ◽

Soft Soil ◽

Site Characterization ◽

Standard Penetration Test ◽

Alluvial Fan ◽

Earthquake Hazards ◽

Ground Acceleration ◽

Site Class ◽

Near Surface

Abstract Site characterization is one of the most important components in seismic hazard analysis because it accounts for the important effects of near‐surface geology on ground motion. It is usually quantified based on the time‐averaged S‐wave velocity (VS) for the top 30 m of the profile (VS30). In this study, we estimate the site class in Jakarta based on VS structure estimated using microtremor array observations. The results show that microtremor‐derived VS profiles agree well with standard penetration test‐derived profiles at nine sites. The site‐class estimates in the Jakarta area can be divided into two National Earthquake Hazards Reduction Program classes: (a) site class E (soft soil) located in alluvium, beach ridge, and alluvial fan deposits in northern and western Jakarta, and (b) site class D (stiff soil) found mainly in alluvial fan deposits in southeastern Jakarta. The variation of VS30 in Jakarta leads to different soil amplification factors that will impact the seismic hazard at the surface. We show that the seismic hazard resulting from selected ground‐motion models (GMMs) illustrates a clear influence of site effects at long periods (>1 s). However, the effect on peak ground acceleration and response spectra for short periods (0.2 s) appear to be less pronounced, due to the GMMs’ treatment of basin effects and nonlinear soil behavior. Available GMMs may not accurately account for such effects in the Jakarta basin, and GMMs specific to Indonesia should be developed to accurately assess seismic hazard there.

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Tailored acquisition and processing providing an enhanced subsurface image of the basin architecture, Exmouth Sub-basin, North West Shelf, Australia

The APPEA Journal ◽

10.1071/aj18155 ◽

2019 ◽

Vol 59 (2) ◽

pp. 886

Author(s):

Alexander Karvelas ◽

Bee Jik Lim ◽

Lianping Zhang ◽

Haryo Trihutomo ◽

Oliver Schenk ◽

...

Keyword(s):

Oil And Gas ◽

Model Building ◽

Waveform Inversion ◽

Hydrocarbon Exploration ◽

Surface Velocity ◽

Seismic Survey ◽

Image Point ◽

Surface Model ◽

Near Surface ◽

North West

Hydrocarbon exploration has resulted in the discovery of a variety of oil and gas accumulations mainly in Upper Jurassic and Lower Cretaceous intervals. However, the distribution of the different petroleum system elements including Jurassic and Triassic intervals is poorly determined, but required for improved understanding of the complex charge history, as indicated by the variety of hydrocarbon types encountered in the basin. The new WesternGeco multiclient 3D seismic survey extends to the edges of the basin to give a comprehensive picture. Raw hydrophone data were delivered from the vessel as acquisition progressed to begin the near-surface model building. The model building consisted of two major stages: first, using full waveform inversion (FWI) to derive the near-surface velocity field; and, second, common image point (CIP) tomography to update the deeper section beyond the FWI illumination zone. As illustrated herein, various stages of processing and imaging provided a cleaner and crisper dataset across the record length, allowing (1) detailed picking of the events within the entire Mesozoic (Cretaceous–Triassic) section allowing key events to be interpreted and correlated across the area and (2) accurate investigation of the complexity of different aged fault networks and their relationships across the full Exmouth Sub-basin for the first time. In summary, this survey provides a detailed insight into the deeper basin architecture of the Exmouth Sub-basin. The seamless volume imaged to depth allows accurate mapping which is critical to unravel the complex evolutionary history in a basin with proven and significant remaining hydrocarbon potential.

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Repeatability study of seismic source signatures

Geophysics ◽

10.1190/1.1487123 ◽

2001 ◽

Vol 66 (6) ◽

pp. 1811-1817 ◽

Cited By ~ 19

Author(s):

Bibi C. Aritman

Keyword(s):

Phase Difference ◽

Seismic Source ◽

Seismic Survey ◽

Surface Source ◽

Near Surface ◽

Seismic Surveys ◽

Instantaneous Phase ◽

Reservoir Monitoring ◽

The Difference

This study discusses the repeatability of source signature using the instantaneous phase, as derived from the complex trace attributes. The study is part of a very large 2‐D seismic survey using sources of vibroseis and surface dynamite. The field procedure consisted of recording the production record, retaining the positions, then repeat‐recording the same shake or shot. The instantaneous phase was found to be the best measure for the difference between the first and the repeat records. In addition to the instantaneous phase, other analyses were used to evaluate changes in source signature. Results were tabulated for statistical comparisons and graded for quality. Excluding erroneous cases, the remainder of poor repeatabilities were studied. The analyses of near‐offset data seem to indicate that nonrepeatability of source signature relates mostly to changes in absorption and cohesion induced by elastic saturation at the near surface. In general, by time shifting and phase rotating the repeat record, the difference in instantaneous phase tends to diminish. The new idea of using instantaneous phase difference plots to evaluate repeatability offers improved evaluation of source signatures and can also be used to detect time‐lapsed changes in reservoir monitoring. By evaluating repeatability and avoiding elastic saturation near the surface, source signatures can be made more consistent, thus increasing the resolution of stacked data for 2‐D, 3‐D, and 4‐D seismic surveys.

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Study on frequency content of provided strong ground motion in West Azerbaijan and East Azerbaijan

Ukrainian Journal of Ecology ◽

10.15421/2017_125 ◽

2017 ◽

Vol 7 (4) ◽

pp. 340-348

Author(s):

Katayoun Behzadafshar

Keyword(s):

Ground Motion ◽

Strong Ground Motion ◽

Frequency Content ◽

Ground Acceleration ◽

Maximum Acceleration ◽

North West ◽

Large Cities ◽

Industrial Software ◽

East Azerbaijan ◽

Strong Ground

This study aims to better reveal the characteristics of the assessed ground motion in west and east Azerbaijan. Due to existence of happened great earthquakes and large number of potential seismic sources in North-West of Iran which is located in junction of Alborz and Zagros seismotectonic provinces, it is an interesting area for seismologists. Considering to population and existence of large cities like Tabriz, Ardabil and Orumiyeh which play crucial role in industry and economy of Iran, authors decided to focus on study of frequency content of strong ground motion to achieve ground acceleration in different frequencies indicate critical frequencies in the studied area. in this study have been applied is professional industrial software which has been written in 2009 and provided by authors; Because This applied software can cover previous software weak points very well. Obtained hazard maps illustrate that maximum accelerations will be experienced in North West to South East direction which increased by frequency reduction from 100 Hz to 10 Hz then decreased by frequency reduce (to 0.25 Hz). Maximum acceleration will be occurred in the basement in 10 Hz.

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Characteristics of the Strong Ground Motion from the 24th August 2016 Amatrice Earthquake

Annals of Geophysics ◽

10.4401/ag-7219 ◽

2016 ◽

Vol 59 ◽

Author(s):

Marta Pischiutta ◽

Aybige Akinci ◽

Luca Malagnini ◽

André Herrero

Keyword(s):

Ground Motion ◽

Peak Ground Acceleration ◽

Normal Fault ◽

Peak Ground Velocity ◽

Rupture Directivity ◽

Ground Acceleration ◽

Ground Shaking ◽

North West ◽

Motion Characteristics ◽

2016 Amatrice Earthquake

The 2016 August 24 Amatrice earthquake occurred at 03:36 local time in Central Apennines Italy with an epicentre at 43.36°E, 38.76°N, Istituto Nazionale di Geofisica e Vulcanologia (INGV), few kilometers north of the city of Amatrice. The earthquake ruptured a North-West (NW)–South-East (SE) oriented normal fault dipping toward the South-West (SW) (Scognamiglio et al., 2016). High values of peak ground acceleration (~0.45 g) were observed close to Amatrice (3 stations being few kilometer distances from the fault). The present study presents an overview of the main features of the seismic ground shaking during the Amatrice earthquake. We analyze the ground motion characteristics of the main shock in terms of peak ground acceleration (PGA), peak ground velocity (PGV) and spectral accelerations (SA, 5 per cent of critical damping). In order to understand the characteristics of the ground motions induced by Amatrice earthquake, we also study the source-related effects relative to the fault rupture directivity.

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Evaluation of strong ground motion for Yogyakarta depression area, Indonesia

Journal of Applied Geology ◽

10.22146/jag.7249 ◽

2015 ◽

Vol 2 (2) ◽

Author(s):

Myo Thant ◽

Subagyo Pramumijoyo ◽

Heru Hendrayana ◽

Hiroshi Kawase ◽

Agus Darmawan Adi

Keyword(s):

Seismic Hazard ◽

Ground Motion ◽

Peak Ground Acceleration ◽

Strong Ground Motion ◽

Seismic Source ◽

Probabilistic Seismic Hazard ◽

Hazard Maps ◽

Ground Acceleration ◽

Seismic Hazard Maps ◽

Strong Ground

The probabilistic seismic hazard maps are developed for Yogyakarta depression area. The earthquake catalog of ANSS (1970-2007) is taken into account with the complement of NEIC (USGS, 1973-2007) and the records of BMG (2000-2004). On the basis of seismicity of the area, tectonics and geological information, the seismic source zones are characterized for this area. The seismicity parameters of each seismic source are determined by applying the classical Gutenberg-Richter recurrence model, regarding the historical records. The attenuation relation for Yogyakarta depression area cannot be evaluated since the sufficient strong ground motion records are not available for this region. Therefore the attenuation relations which were developed for other territories as Europe and Japan are used for the present hazard calculation by validating, using the aftershocks records, modeling the peak ground acceleration maps for the recent event, 27 May, 2006, Yogyakarta earthquake inserting the damage area distribution pattern. The probabilistic seismic hazard maps are finally developed by using the McGuire (1976) EQRISK computer program by modifying for the present purpose. The seismic hazard maps expressed in term of peak ground acceleration are developed for the recurrence intervals of 10, 50, 100, 200 and 500 years

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Site effects of the Denis-Perron dam (SM-3): A case study in Eastern North America

Earthquake Spectra ◽

10.1177/87552930211019439 ◽

2021 ◽

pp. 875529302110194

Author(s):

Daniel Verret ◽

Denis LeBœuf ◽

Éric Péloquin

Keyword(s):

North America ◽

Ground Motion ◽

Site Effects ◽

Transfer Functions ◽

Ground Motions ◽

Published Data ◽

Eastern North America ◽

Ground Acceleration ◽

Large Dams ◽

Moderate Seismicity

Eastern North America (ENA) is part of a region with low-to-moderate seismicity; nonetheless, some significant seismic events have occurred in the last few decades. Recent events have reemphasized the need to review ENA seismicity and ground motion models, along with continually reevaluating and updating procedures related to the seismic safety assessment of hydroelectric infrastructures, particularly large dams in Québec. Furthermore, recent researchers have shown that site-specific characteristics, topography, and valley shapes may significantly aggravate the severity of ground motions. To the best of our knowledge, very few instrumental data from actual earthquakes have been published for examining the site effects of hydroelectric dam structures located in eastern Canada. This article presents an analysis of three small earthquakes that occurred in 1999 and 2002 at the Denis-Perron (SM-3) dam. This dam, the highest in Québec, is a rockfill embankment structure with a height of 171 m and a length of 378 m; it is located in a narrow valley. The ground motion datasets of these earthquakes include the bedrock and dam crest three-component accelerometer recordings. Ground motions are analyzed both in the time and frequency domains. The spectral ratios and transfer functions obtained from these small earthquakes provide new insights into the directionality of resonant frequencies, vibration modes, and site effects for the Denis-Perron dam. The crest amplifications observed for this dam are also compared with previously published data for large dams. New statistical relationships are proposed to establish dam crest amplification on the basis of the peak ground acceleration (PGA) at the foundation.

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From scenario-based seismic hazard to scenario-based landslide hazard: fast-forwarding to the future via statistical simulations

Stochastic Environmental Research and Risk Assessment ◽

10.1007/s00477-021-02020-1 ◽

2021 ◽

Author(s):

Luigi Lombardo ◽

Hakan Tanyas

Keyword(s):

Ground Motion ◽

Landslide Susceptibility ◽

Additive Model ◽

Landslide Hazard ◽

Northridge Earthquake ◽

Ground Acceleration ◽

Temporal Dimension ◽

Earthquake Scenario ◽

The Mean ◽

Ground Motion Scenarios

AbstractGround motion scenarios exists for most of the seismically active areas around the globe. They essentially correspond to shaking level maps at given earthquake return times which are used as reference for the likely areas under threat from future ground displacements. Being landslides in seismically actively regions closely controlled by the ground motion, one would expect that landslide susceptibility maps should change as the ground motion patterns change in space and time. However, so far, statistically-based landslide susceptibility assessments have primarily been used as time-invariant.In other words, the vast majority of the statistical models does not include the temporal effect of the main trigger in future landslide scenarios. In this work, we present an approach aimed at filling this gap, bridging current practices in the seismological community to those in the geomorphological and statistical ones. More specifically, we select an earthquake-induced landslide inventory corresponding to the 1994 Northridge earthquake and build a Bayesian Generalized Additive Model of the binomial family, featuring common morphometric and thematic covariates as well as the Peak Ground Acceleration generated by the Northridge earthquake. Once each model component has been estimated, we have run 1000 simulations for each of the 217 possible ground motion scenarios for the study area. From each batch of 1000 simulations, we have estimated the mean and 95% Credible Interval to represent the mean susceptibility pattern under a specific earthquake scenario, together with its uncertainty level. Because each earthquake scenario has a specific return time, our simulations allow to incorporate the temporal dimension into any susceptibility model, therefore driving the results toward the definition of landslide hazard. Ultimately, we also share our results in vector format – a .mif file that can be easily converted into a common shapefile –. There, we report the mean (and uncertainty) susceptibility of each 1000 simulation batch for each of the 217 scenarios.

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