scholarly journals Spatiotemporal Evolution of a Landslide: A Transition to Explosive Percolation

Entropy ◽  
2020 ◽  
Vol 22 (1) ◽  
pp. 67 ◽  
Author(s):  
Kushwant Singh ◽  
Antoinette Tordesillas
Keyword(s):  
Percolation Theory ◽  
Ground Motions ◽  
Connected Components ◽  
Early Prediction ◽  
Critical Transition ◽  
Spatiotemporal Evolution ◽  
Evolving Graphs ◽  
Motion Data ◽  
Recent Developments ◽  
Failure Precursors

Patterns in motion characterize failure precursors in granular materials. Currently, a broadly accepted method to forecast granular failure from data on motion is still lacking; yet such data are being generated by remote sensing and imaging technologies at unprecedented rates and unsurpassed resolution. Methods that deliver timely and accurate forecasts on failure from such data are urgently needed. Inspired by recent developments in percolation theory, we map motion data to time-evolving graphs and study their evolution through the lens of explosive percolation. We uncover a critical transition to explosive percolation at the time of imminent failure, with the emerging connected components providing an early prediction of the location of failure. We demonstrate these findings for two types of data: (a) individual grain motions in simulations of laboratory scale tests and (b) ground motions in a real landslide. Results unveil spatiotemporal dynamics that bridge bench-to-field signature precursors of granular failure, which could help in developing tools for early warning, forecasting, and mitigation of catastrophic events like landslides.

scholarly journals Rupture model of the 1989 Loma Prieta earthquake from the inversion of strong-motion and broadband teleseismic data

1991 ◽  
Vol 81 (5) ◽  
pp. 1540-1572 ◽  
Author(s):  
David J. Wald ◽  
Donald V. Helmberger ◽  
Thomas H. Heaton
Keyword(s):  
Ground Motion ◽  
Ground Motions ◽  
Strong Motion ◽  
High Gain ◽  
Temporal And Spatial Distribution ◽  
Origin Time ◽  
Loma Prieta Earthquake ◽  
Motion Data ◽  
Teleseismic Data ◽  
Loma Prieta

Abstract We have used 24 broadband teleseismic and 48 components of local strong-motion velocity records of the 1989 Loma Prieta earthquake in a formal inversion to determine the temporal and spatial distribution of slip. Separate inversions of the teleseismic data (periods of 3 to 30 sec) or strong-motion data (periods of 1 to 5 sec) result in similar models. The data require bilateral rupture with relatively little slip in the region directly updip from the hypocenter. Slip is concentrated in two patches: one centered 6 km northwest of the hypocenter at a depth of 12 km and with a maximum slip of 350 cm, and the other centered about 5 km southeast of the hypocenter at a depth of 16 km and with a maximum slip of 460 cm. The bilateral nature of the rupture results in large amplitude ground motions at sites located along the fault strike, both to the northwest and the southeast. However, the northwestern patch has a larger moment and overall stress drop and is, consequently, the source of the largest ground motion velocities, consistent with the observed recordings. This bilateral rupture also produces relatively modest ground motion amplitudes directly updip from the hypocenter, which is in agreement with the velocity ground motions observed at Corralitos. There is clear evidence of a foreshock (magnitude between 3.5 and 5.0) or a slow rupture nucleation about 2 sec before the main part of the rupture; the origin time implied by strong-motion trigger times is systematically 2 sec later than the time predicted from the high-gain regional network data. The seismic moment obtained from either of the separate data sets or both sets combined is about 3.0 × 1026 dyne-cm and the potency is 0.95 km3.

Overview of strong-motion data from the Darfield earthquake

2010 ◽  
Vol 43 (4) ◽  
pp. 222-227 ◽  
Author(s):  
Jim Cousins ◽  
Graeme H. McVerry
Keyword(s):  
Main Shock ◽  
Ground Motions ◽  
Strong Motion ◽  
Vertical Acceleration ◽  
Strong Motion Data ◽  
Motion Data ◽  
Near Fault ◽  
Long Period ◽  
Fault Record ◽  
Stiff Soil

The Darfield earthquake of 3rd September 2010 UT and its aftershocks have yielded New Zealand’s richest set of strong-motion data since recording began in the early 1960s. Main-shock accelerograms were returned by 130 sites, ten of which had peak horizontal accelerations in the range 0.3 to 0.82g. One near-fault record, from Greendale, had a peak vertical acceleration of 1.26g. Eighteen records showed peak ground velocities exceeding 0.5 m/s, with three of them exceeding 1 m/s. The records included some with strong long-period directivity pulses, some with other long-period components that were related to a mixture of source and site effects, and some that exhibited the effects of liquefaction at their sites. There were marked differences between records on the deep alluvium of Christchurch City and the Canterbury Plains, and those on shallow stiff soil sites. The strong-motion records provide the opportunity to assess the effects of the earthquake in terms of the ground motions and their relationship to design motions. They also provide an invaluable set of near-source motions for seismological studies. Our report presents an overview of the records and some preliminary findings derived from them.

scholarly journals Ground motions variability in Israel from 3-D simulations of M 6 and M 7 earthquakes

2021 ◽  
Author(s):  
Jonatan Glehman ◽  
Michael Tsesarsky
Keyword(s):  
Ground Motion ◽  
Ground Motions ◽  
Peak Ground Velocity ◽  
Motion Data ◽  
Ground Motion Model ◽  
Spatial Coverage ◽  
Seismicity Rates ◽  
Shear Rupture ◽  
Single Station ◽  
Simulated Ground Motions

Abstract. In Israel, due to low seismicity rates and sparse seismic network, the temporal and spatial coverage of ground motion data is insufficient to estimate the variability of moderate-strong (M > 6) ground motions required to construct a local ground motion model (GMM). To fill this data gap and to study the ground motions variability of M > 6 events, we performed a series of 3-D numerical simulations of M 6 and M 7 earthquakes. Based on the results of the simulations, we developed a statistical attenuation model (AM) and studied the residuals between simulated and AM PGVs and the single station variability. We also compared the simulated ground motions with a global GMM in terms of peak ground velocity (PGV) and significant duration (Ds 595). Our results suggest that the AM was unable to fully capture the simulated ground motions variability, mainly due to the incorporation of super-shear rupture and effects of local sedimentary structures. We also show that an imported GMM considerably deviates from simulated ground motions. This work sets the basis for future development of a comprehensive GMM for Israel, accounting for local sources, path, and site effects.

Ground motion amplification factors for the proposed 2005 edition of the National Building Code of Canada

2003 ◽  
Vol 30 (2) ◽  
pp. 272-278 ◽  
Author(s):  
W.D Liam Finn ◽  
Adrian Wightman
Keyword(s):  
Seismic Design ◽  
Ground Motions ◽  
Building Code ◽  
Soil Conditions ◽  
Site Conditions ◽  
Amplification Factors ◽  
Seismic Codes ◽  
Local Soil ◽  
Recent Developments ◽  
Site Classes

Foundation factors are used in seismic codes to capture the amplification effects of local soil conditions on ground motions and, hence, on seismic design forces. Recent developments in categorizing site conditions for seismic codes and assigning intensity- and frequency-dependent amplification factors to the various site classes are presented to provide a basis for understanding the new foundation factors proposed for the 2005 edition of the National Building Code of Canada.Key words: design spectra, site characterization, amplification factors.

Seismic Response of a Hill in Wenxian, Gansu, Observed from Aftershocks of 2008 Wenchuan Earthquake

2011 ◽  
Vol 243-249 ◽  
pp. 3952-3957 ◽  
Author(s):  
Yu Xia Lu ◽  
Kun Liu ◽  
Yu Cheng Shi ◽  
Qian Li
Keyword(s):  
Site Response ◽  
Ground Motions ◽  
Strong Motion ◽  
Spectral Ratio ◽  
Gansu Province ◽  
Spectra Analysis ◽  
2008 Wenchuan Earthquake ◽  
Motion Data ◽  
Source Effects ◽  
The Hill

To help understand the ground motions of the topographic site, the workers of Seismic Bureau of Gansu province deployed a temporary array of seismometers around the Wenxian hill and recorded ground motions from Wenchuan aftershocks. Only 11 aftershocks were recorded on all stations across the hill, these data were collected to facilitate studies of site response, wave propagation effect, and correlations of mainshock damage with local site conditions. In this paper, we analyze the weak motion data as well as the strong-motion data, and conduct comparisons of peak ground accelerations, seismic spectra analysis, and spectral ratio analysis. A more complete description of the site’s amplification, its relationship to topography, and its relationship to earthquake source effects are provided. The result shows that the ground motion was consistently amplified at station at or near the top of the hill compared with stations at the base of the hill and the amplifications frequency dependent and has its maximum at the resonant frequency of the site.

The SMART I Accelerograph Array (1980-1987): A Review

1987 ◽  
Vol 3 (2) ◽  
pp. 263-287 ◽  
Author(s):  
N. A. Abrahamson ◽  
B. A. Bolt ◽  
R. B. Darragh ◽  
J. Penzien ◽  
Y. B. Tsai
Keyword(s):  
Ground Motion ◽  
Earthquake Engineering ◽  
Ground Motions ◽  
Near Field ◽  
Strong Motion ◽  
Response Spectra ◽  
Transform Faults ◽  
Engineering Research ◽  
Motion Data ◽  
Time Histories

SMART 1 is the first large digital array of strong-motion seismographs specially designed for engineering and seismological studies of the generation and near-field properties of earthquakes. Since the array began operation in September 1980, it has recorded over 3000 accelerogram traces from 48 earthquakes ranging in local magnitude ( ML) from 3.6 to 7.0. Peak ground accelerations have been recorded up to 0.33g and 0.34g on the horizontal and vertical components, respectively. Epicentral distances have ranged from 3 km 200 km from the array center, and focal depths have ranged from shallow to 100 km. The recorded earthquakes had both reverse and strike-slip focal mechanisms associated with the subduction zone and transform faults. These high quality, digital, ground motions provide a varied resource for earthquake engineering research. Earthquake engineering studies of the SMART 1 ground motion data have led to advances in knowledge in several cases: for example, on frequency-dependent incoherency of free-surface ground motions over short distances, on response of linear systems to multiple support excitations, on attenuation of peak ground-motion parameters and response spectra, on site torsion and phasing effects, and on the identification of wave types. Accelerograms from individual strong-motion seismographs do not, in general, provide such information. This review describes the SMART 1 array and the recorded earthquakes with special engineering applications. Also, it tabulates the unfiltered peak array accelerations, displays some of the recorded ground motion time histories, and summarizes the main engineering research that has made use of SMART 1 data.

Web-Based Virtual Seismic Monitoring for Pipelines

2013 ◽  
Author(s):  
Douglas J. Nyman ◽  
Robert L. Nigbor
Keyword(s):  
Ground Motion ◽  
Ground Motions ◽  
Strong Motion ◽  
Seismic Monitoring ◽  
Scientific Data ◽  
Soil Conditions ◽  
Pipeline System ◽  
Web Based ◽  
Motion Data ◽  
Liquefaction Hazard

Strong motion seismic monitoring systems are often installed at critical industrial facilities located in areas of moderate to high seismicity. The objective of seismic monitoring is to facilitate post-earthquake evaluation and emergency action by providing rapid detection of seismic events and associated data, alarms, and information. Seismic monitoring can play a similar role for pipelines, especially considering the added geohazard risks along right-of-ways that might include landslides, fault crossings, and liquefaction hazard areas. Because of spatial distribution, seismic monitoring for pipelines is more complex than that required for a site-specific facility. In recent years, graphical software known as “ShakeMap,” developed by U.S. Geological Survey (USGS), has been used to rapidly estimate and distribute the distribution and intensity of earthquake ground motions from an earthquake. The ShakeMap solution for ground motions takes into account the distance from the earthquake source, the rock and soil conditions at sites, and variations in the propagation of seismic waves due to complexities in the structure of the Earth’s crust. ShakeMap ground motion data is available for automatic download from the USGS for potentially damaging earthquakes, e.g., Magnitude 5 and greater, within minutes after the event. USGS’ ShakeMap provides the opportunity to implement web-based systems to conduct automatic seismic monitoring for cross-county pipelines or networks of pipelines. A monitoring website can be equipped with a seismic database of fragilities that characterize geohazard vulnerabilities along pipeline right-of-ways as well as support facilities. Website software can be used to process the ground motion data to assess the threat to the pipeline system, advise pipeline controllers on the need for shutdown, and guide post-earthquake inspection on a prioritized basis. Drawing from the authors’ recent seismic monitoring experience for the Trans-Alaska Pipeline and other lifeline facilities, a conceptual plan for web-based seismic monitoring for pipelines is presented. The choice of a software platform can range from the use of open-source software available from USGS (ShakeCast) to custom software making direct use of gridded data downloads. Regardless of implementation strategy, the most convincing point to be made is that a seismic monitoring system need not require the installation of seismic instruments and the associated commitment to maintenance and hands-on seismology; instead it makes use of publicly available scientific data for rapid post-earthquake assessment.

scholarly journals Empirical Spectral Amplification Function for a Reference Site Near Keddara Dam in Algeria using Strong Motion Data.

2021 ◽  
Author(s):  
Faouzi Gherboudj ◽  
Toufiq Ouzandja ◽  
Rabah Bensalem
Keyword(s):  
Ground Motion ◽  
Reference Site ◽  
Ground Motions ◽  
Free Field ◽  
Strong Motion ◽  
Ambient Vibration ◽  
Motion Prediction ◽  
Ground Motion Prediction ◽  
Strong Motion Data ◽  
Motion Data

Abstract This paper deals with empirical spectral amplification function for a reference site (STK) near Keddara dam in Algeria using local strong ground motion of earthquakes of magnitudes Mw 4.0-6.8. Amplification function is obtained as the 5% damped mean spectral ratio of surface observed and the rock predicted ground motions and it is compared to the ambient vibration HVSR which shows a good agreement in terms of fundamental frequency and curve tendency. In addition, recorded ground motions are compared to surface predicted motion with modified GMPE, the site term of the local ground motion prediction equation is adjusted based on the obtained amplification function of the free field STK site. Examples of the M 6.8, M5.4 and M4.7 earthquakes show clearly the advantage of using the adjusted Ground Motion Prediction Equations (GMPE) for predicting surface ground motion. Site effect characterization and the adjusted GMPE presented in this study provide the basis elements toward partially non ergodic site specific-Probabilistic seismic hazard assessment (PSHA) application based on local strong motion data in Algeria.

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