Intensity Of Seismic Shaking Research Articles

Seismotectonic Deformation of the Early Medieval Fortress Wall of Derbent (Dagestan)

The results of the latest research on active faults in Southern Dagestan, in the area of Derbent, using the paleoseismological and archeoseismological methods are highlighted. The zone of seismogenerating fault—the Derbent segment of the regional tectonic boundary between the mountain structure of the Greater Caucasus and the North Caucasian foredeep—is revealed. The last seismotectonic slip along the fault due to a strong earthquake led to the displacement of the early medieval city wall of Derbent. The magnitude of this event was M ≈ 7, and, therefore, the seismic shaking intensity was I0 ≥ IX. This seismic event occurred, most likely, in the 10th century AD.

Automated Estimation of Seismic Shaking Intensity from Instrumental Data in Quasi-Real-time Mode and Its Use in the Operation of the of Seismic Early Warning Service in the Kamchatka Region

Early warning systems are becoming increasingly important in the modern world. These systems combine several components: predictive systems (For example, tsunami warning systems), earthquake early warning systems, emergency message services, and systems of seismic damage monitoring. Information about shaking intensity becomes especially important in the case of a strong earthquake occurrence. These data are necessary for planning emergency rescue operations, but they are difficult to collect in a natural disasters situation because of possible communication problems. Application of data on instrumental seismic intensity may make it possible to solve this problem. Early warning systems predicting seismic intensity distributions just after the occurrence of an earthquake have already been developed in many seismically active regions of the world. Such a system also needs to be implemented in Kamchatka, where the strongest earthquakes can produce extremely high values of strong motion acceleration. As a result of the development of a system for seismological observation in Kamchatka, a unified specialized system for collection, transmission, archiving, and processing of seismic information was created. Seismological observations in Kamchatka were significantly improved with the update of the tsunami warning service in 2006–2011. As a result, a network of strong motion stations is currently operating in Kamchatka and can serve as a basis for creating a quasi-real-time seismic early warning system under the auspices the Kamchatka Branch of the Geophysical Survey, Russian Academy of Sciences (KB GS RAS). It uses data from strong motion stations to estimate the instrumental seismic intensity in quasi-real-time mode and visualizes the results. During the operational period while the service is being intensively used in the framework of the Seismic Early Warning Reports Tsunami Warning Service in the Kamchatka and Sakhalin branches of the GS RAS for real-time warning of interested parties about the shaking intensities at observation points, the technology implemented in this service has proved highly informative. In total, 75 messages on instrumental intensity in various places of Kamchatka krai and the northern Kuril Islands (Paramushir Islands) have been sent since the service was commissioned at the end of 2014. The currently operating version of the service has proved its informativeness and applicability for special departments of the Emergency Situations Ministry. In addition, real-time warning has improved coordination between the departments of KB GS RAS, and the results of this system are being used in a number of basic research projects. Further development of the service is related to the creation of denser instrumental networks to record strong ground motions and the transition to automatic decision-making and message sending.

Vichada meteorite impact effects from simulation of regional environmental consequences of a meteoroid impact on Earth

This study estimates the regional environmental consequences of the impactor extraterrestrial body that could produce the probable Vichada impact crater structure on the Vichada Plain, in Colombia, South America. This paper details the parameter assumptions upon which the estimation is made. It describes an approach to quantifying the principal impact processes that could have affected the landscape in the vicinity of the probable Vichada impact event in the past. The key parameters are impactor diameter, impactor density, impact velocity before atmospheric entry, impact angle, and the distance from the impact at which the environmental effects are to be calculated, and the target type of sedimentary rock or crystalline rock. These parameters were chosen with support from The Vichada Structure dimensions obtained from remote sensing data interpretation, regional geologic mapping and interpreted satellite data and ground-based gravity and magnetic anomalies. The calculations are based on compiled novel algorithms for estimating the thermal radiation emitted by the impact-generated vapor plume or fireball, and the intensity of seismic shaking. Model validation is performed by obtaining the approximates various dimensions of the Vichada impact crater and ejecta deposit, as well as estimating the severity of the air blasting both crater-forming and air burst impacts. We illustrate the utility of the calculations by examining the predicted environmental consequences in seven localities of the Colombian territory, through hypothetical impact scenarios occurring in Cumaribo and Puerto Carreño (Vichada), Puerto Inirida (Guainía), Puerto Gaitán and Villavicencio (Meta), Mitú (Vaupes) and Bogotá, D.C. It is concluded that the most wide-reaching environmental consequence is seismic shaking. Both ejecta deposit thickness and air-blast pressure decay much more rapidly with distance than with seismic ground motion. Close to the impact site, the most devastating effect is from thermal radiation; however, the curvature of the Earth implies that distant localities are shielded from direct thermal radiation because the fireball is below the horizon. These results would guide further detailed fieldwork hunting for direct impact crater evidence and interpret high-resolution geophysical studies and borehole that could be carried out in the probable Vichada impact crater area shortly.

Post-disaster infrastructure restoration: A comparison of events for future planning

The restoration of lifeline infrastructures following a major disruptive disaster is a complex task. Along with the implementation of mitigation measures, pre-event recovery planning can be of great assistance to this process. This paper seeks to inform such planning discussions by suggesting likely paths of recovery over time, and in turn computing indicative estimates of expected restoration times. While current methods can require significant amounts of data and are calibrated to few events, the presented approach analyses and combines 63 electricity, water, gas, and telecommunications post-disaster infrastructure recoveries from across the world. Recoveries are compared across disaster types with global median recovery curves produced to inform likely restoration rates for future disasters. Models based on initial outages or seismic shaking intensity directly provide estimates of expected recovery times back to 90% operability of the initial disruption. An application of the presented methodology is presented as a case study for the Wellington Region of New Zealand with recovery estimates comparing favorably with those presented in the literature.

Influence of isolation hysteresis on the seismic performance of isolated buildings

Seismic isolation is one of the most used protective technologies for earthquake engineering. Many innovative devices have been researched and implemented. Selection of the different isolation devices is commonly based on engineering experience, where no detailed and systematic comparison has been provided. In this paper, the seismic performances of a three-story office building isolated using five different devices were evaluated. The isolation devices included the bilinear, flag-shaped I, flag-shaped II, crystallizing rubber (CR), and rigid-perfectly plastic (RPP) models. These isolation devices were designed to achieve an equivalent performance at the seismic shaking intensity of 2% probability of exceedance in 50 years. The evaluation was conducted using the state-of-the-art assessment procedure at 2%, 10%, and 50% probability of exceedance in 50 years (50/50, 10/50, and 2/50) hazard levels. The results indicated that all the isolators performed well by limiting the financial losses. At both the 50/50 and 10/50 shaking intensities, the building with CR isolators experienced no repair costs, while those with bilinear, flag-shaped I, flag-shaped II, and RPP isolators had minor repair costs contributed from the content performance groups. At the 2/50 shaking intensity, all isolators incurred minor damages in the content performance groups. The building with CR isolators had additional repair costs because of the interior drift sensitive nonstructural components, while the building with the RPP isolators had repair costs contributed from the interior drift and acceleration sensitive nonstructural components and the acceleration sensitive equipment at the roof. Copyright © 2014 John Wiley & Sons, Ltd.

The effect of glaciation on the intensity of seismic ground motion

ABSTRACTSeismicity is known to contribute to landscape denudation through its role in earthquake‐triggered slope failure; but little is known about how the intensity of seismic ground motions, and therefore triggering of slope failures, may change through time. Topography influences the intensity of seismic shaking – generally steep slopes amplify shaking more than flatter slopes – and because glacial erosion typically steepens and enlarges slopes, glaciation may increase the intensity of seismic shaking of some landforms. However, the effect of this may be limited until after glaciers retreat because valley ice or ice‐caps may damp seismic ground motions. Two‐dimensional numerical models (FLAC 6.0) were used to explore how edifice shape, rock stiffness and various levels of ice inundation affect edifice shaking intensity. The modelling confirmed that earthquake shaking is enhanced with steeper topography and at ridge crests but it showed for the first time that total inundation by ice may reduce shaking intensity at hill crests to about 20–50% of that experienced when no ice is present. The effect is diminished to about 80–95% if glacier ice level reduces to half of the mountain slope height. In general, ice cover reduced shaking most for the steepest‐sided edifices, for wave frequencies higher than 3 Hz, and when ice was thickest and the rock had shear stiffness well in excess of the stiffness of ice. If rock stiffness is low and shear‐wave velocity is similar to that of ice, the presence of ice may amplify the shaking of rock protruding above the ice surface. The modelling supports the idea that topographic amplification of earthquake shaking increases as a result of glacial erosion and deglaciation. It is possible that the effect of this is sufficient to have influenced the distribution of post‐glacial slope failures in glaciated seismically active areas. Copyright © 2012 John Wiley & Sons, Ltd.

Microcontroller-based Seismic-ShakingIntensity Meter

Abstract A microcontroller-based seismic shaking intensity meter is developed and tested. This device will bemounted in many high rise building that can be found mainly in big city like Jakarta. The device willrecord information on earthquake s magnitude in the building which is taken by using accelerometer;later on the data will be compared with the real earthquake s magnitude that is taken using seismograph.Data on device position, time, and magnitude level will be sent through Short Message Services (SMS)via Global System for Mobile Communications (GSM) networks to server. The result showed that theaccuracy is 95% compared to the commercial seismograph measurement.© 2012 Published by Elsevier Ltd. Selection and/or peer-review under responsibility of Bina Nusantara University Keywords: earthquake, seismic intensity meter, accelerometer, GSM, microcontroller, AVR 1. Introduction Indonesia is often referred to as the world's largest archipelago[1] whichsurroundedbylotsofactivevolcano and placed in between two giant tectonic plates[2]. Having this richness means that earthquakesometimes happened, and for a big city like Jakarta, it is necessary to have safety high rise building andprevention system.The prevention building system consist of pre-earthquake, that is by continuousmonitoring building structure and post-earthquake by develop several strategy to minimize the earthquakedamage[3]. The Indonesian Agency for Meteorology, Climatology, and Geophysics (BMKG) detects theearthquake by using seismograph[4], records it using paper andthe data saving is done manually. There

Media velocity model and macroseismic effect: The Spitak earthquake of December 7, 1988

Relationship between the intensity of seismic shaking on the surface and the velocity structure of the medium at large depth is studied. The Spitak earthquake of December 7, 1988 is chosen as an object of study. A method to correlate the intensity of shaking in the localities to the geophysical parameters specified in the nodes of regular spatial grid is proposed. Formalized definition of anomalous intensity is suggested; it takes into account the distribution of distances from the localities with given intensity degrees to the hypocenter or to the nearest segment of the surface fault. It is found that the seismic wave velocities at a depth of 1 km are higher (up to 0.2–0.6 km/s) under the localities with anomalously high intensity. No any certain regularity is found in deeper layers.

Incorporating the effects of topographic amplification in the analysis of earthquake-induced landslide hazards using logistic regression

Abstract. Seismic-induced landslide hazards are studied using seismic shaking intensity based on the topographic amplification effect. The estimation of the topographic effect includes the theoretical topographic amplification factors and the corresponding amplified ground motion. Digital elevation models (DEM) with a 5-m grid space are used. The logistic regression model and the geographic information system (GIS) are used to perform the seismic landslide hazard analysis. The 99 Peaks area, located 3 km away from the ruptured fault of the Chi-Chi earthquake, is used to test the proposed hypothesis. An inventory map of earthquake-triggered landslides is used to produce a dependent variable that takes a value of 0 (no landslides) or 1 (landslides). A set of independent parameters, including lithology, elevation, slope gradient, slope aspect, terrain roughness, land use, and Arias intensity (Ia) with the topographic effect. Subsequently, logistic regression is used to find the best fitting function to describe the relationship between the occurrence and absence of landslides within an individual grid cell. The results of seismic landslide hazard analysis that includes the topographic effect (AUROC = 0.890) are better than those of the analysis without it (AUROC = 0.874).

Ejection Landslide at Northern Terminus of Beichuan Rupture Triggered by the 2008 Mw 7.9 Wenchuan Earthquake

On 12 May 2008, the Mw 7.9 Wenchuan earthquake triggered wide- spread damaging landslides in many parts of the Longmen Shan area. Among these landslides, the Donghekou ejection landslide is quite special. It is located at the north- east end of the Beichuan rupture, and it has caused a great loss of life at the villages of Donghekou, Qinchuan, and Sichuan Provinces. Because of its special location, this ejection landslide differs from landslides caused by gravity or rainstorms only; the sliding surface is not uniformly continuous. Instead, two sections can be distin- guished: an upper section with a step sliding surface and a lower section more gently dipping. The landslide started with material ejection caused by large local seismic acceleration, throwing rocks into the air with a parabolic trajectory before they fell back to the ground. In this paper, we analyze geologic and geomorphologic conditions that favored the occurrence of this landslide, and we introduce a simple tectonic- geomorphology model to explain the mechanism that led to the ejection landslide. We find that the location of the landslide zone, along with the domino-like ground tension cracks observed on both sides of the Beichuan rupture, is controlled by the propagation of the rupture. Our result also suggests that, in addition to local seismic shaking intensity, horizontal acceleration, and geomorphologic and geologic condi- tions, the vertical acceleration and the style of faulting could also play an important role in the occurrence of earthquake-triggered landslides.

Lichenometry dating of coseismic changes to a New Zealand landslide complex

Lichenometry is a surface-exposure-dating procedure that complements traditional trench-and-date stratigraphic studies of earthquakes. Lichens on the surficial blocks of a slump in the Seaward Kaikoura Range, South Island, New Zealand provide precise, accurate (± 2 years) dating of 20 post-landslide rockfall events. The coseismic character of these rockfall events is apparent when ages of lichen-size peaks are compared with dates of historical earthquakes. Most local prehistoric lichen-size peaks are synchronous with peaks at other lichenometry sites in a 20 000 km2 region. Lichenometry may be the best paleoseismic tool for describing the extent and intensity of seismic shaking caused by prehistoric earthquakes, and for dating earthquakes generated by concealed thrust faults and subduction fault zones.

Earth Impact Effects Program: A Web-based computer program for calculating the regional environmental consequences of a meteoroid impact on Earth

Abstract— We have developed a Web-based program for quickly estimating the regional environmental consequences of a comet or asteroid impact on Earth (http:www.lpl.arizona.eduimpacteffects). This paper details the observations, assumptions and equations upon which the program is based. It describes our approach to quantifying the principal impact processes that might affect the people, buildings, and landscape in the vicinity of an impact event and discusses the uncertainty in our predictions. The program requires six inputs: impactor diameter, impactor density, impact velocity before atmospheric entry, impact angle, the distance from the impact at which the environmental effects are to be calculated, and the target type (sedimentary rock, crystalline rock, or a water layer above rock). The program includes novel algorithms for estimating the fate of the impactor during atmospheric traverse, the thermal radiation emitted by the impact-generated vapor plume (fireball), and the intensity of seismic shaking. The program also approximates various dimensions of the impact crater and ejecta deposit, as well as estimating the severity of the air blast in both crater-forming and airburst impacts. We illustrate the utility of our program by examining the predicted environmental consequences across the United States of hypothetical impact scenarios occurring in Los Angeles. We find that the most wide-reaching environmental consequence is seismic shaking: both ejecta deposit thickness and air-blast pressure decay much more rapidly with distance than with seismic ground motion. Close to the impact site the most devastating effect is from thermal radiation; however, the curvature of the Earth implies that distant localities are shielded from direct thermal radiation because the fireball is below the horizon.

The November 25, 1988 Saguenay Earthquake: Isoseismal Survey In Ithaca Region, Central New York

The Saguenay, Quebec Earthquake of November 25, 1988 was widely felt in southeast Canada and in northeast U.S. (Figure 1a). In Ithaca, New York, 795 km southwest of the epicenter, reports of the intensity of shaking caused by this earthquake varied considerably. Intrigued by these variations, we took advantage of this rare event to construct an isoseismal map of the Ithaca area. The results of our study, detailed below, provide a good example of the variability in the intensity of seismic shaking associated with areas of variable surface topography and lithology. The Saguenay earthquake was an unusually deep crustal event (28 km) of moderate magnitude (M = 6) (Gariel and Jacob, 1989; Basham and Adams, 1989). Its focal mechanism indicates thrusting on north-to-northwest trending, intermediate-dipping planes (Wetmiller et al., 1989). The epicenter was near structures related to a failed Paleozoic rift within the Grenville Basement (Adams and Basham, 1989). Felt areas were reported as far (1100 km) as Washington, D.C. (N.Y. Times, November 26, 1988). That the felt area was exceptionally large for an earthquake of this magnitude was not surprising. It has been previously noted (Nuttli, 1973; Nuttli and Zollweg, 1974) that earthquakes in the eastern United States have much larger felt areas than earthquakes of the same magnitude in the western U.S. Nuttli (1973) reports, for example, that the seismic quality factor, Q, for 1-sec waves is 10 times greater in the east than in the west. Questionnaires were printed in a local newspaper and circulated through Cornell . . .

Dynamic analysis of a slope failure from the 6 August 1979 Coyote Lake, California, earthquake

abstract The Coyote Lake, California, earthquake of 6 August 1979 (ML = 5.7) provided a rare opportunity to perform a dynamic numerical analysis of a seismically induced slope failure using actual strong-motion records. The earthquake displaced a preexisting slump on the northeast shore of Lake Anderson and formed a fissure 20 m long; offsets of 9 mm vertically and 18 mm horizontally were measured across the fissure. The slump is 9 km northwest of the located epicenter but within 100 m of the mapped trace of the Calaveras fault. Two strong-motion records were written in the vicinity of the slump: Coyote Creek, 5 km to the southeast, and Gilroy #6, 15 km to the southeast. These records combined with field measurements of the slope, estimates of the material properties, and a dynamic numerical model based on the Newmark analysis of seismic slope stability to calculate a predicted displacement for the landslide. A displacement of 27 mm, calculated using the N50°E component of the Gilroy #6 record, is in excellent agreement with the displacement measured in the field (21 mm). However, displacements of only 0.12 mm, calculated using the 250° component of the Coyote Creek strong-motion record, reflect significant local variations in seismic shaking intensity. Because strong-motion records and slope failures rarely coincide, this landslide provides an important test case for our understanding of the dynamics of seismically induced landslides, as well as a warning that local seismologic variations need to be considered in any design applications.