scholarly journals Earthquakes on the surface: earthquake location and area based on more than 14 500 ShakeMaps

2018 ◽  
Vol 18 (6) ◽  
pp. 1665-1679
Author(s):  
Stephanie Lackner
Keyword(s):  
Ground Motion ◽  
Strong Ground Motion ◽  
Earthquake Location ◽  
Primary Concern ◽  
Ground Acceleration ◽  
Ground Shaking ◽  
Geographic Context ◽  
The Social ◽  
Strong Ground

Abstract. Earthquake impact is an inherently interdisciplinary topic that receives attention from many disciplines. The natural hazard of strong ground motion is the reason why earthquakes are of interest to more than just seismologists. However, earthquake shaking data often receive too little attention by the general public and impact research in the social sciences. The vocabulary used to discuss earthquakes has mostly evolved within and for the discipline of seismology. Discussions on earthquakes outside of seismology thus often use suboptimal concepts that are not of primary concern. This study provides new theoretic concepts as well as novel quantitative data analysis based on shaking data. A dataset of relevant global earthquake ground shaking from 1960 to 2016 based on USGS ShakeMap data has been constructed and applied to the determination of past ground shaking worldwide. Two new definitions of earthquake location (the shaking center and the shaking centroid) based on ground motion parameters are introduced and compared to the epicenter. These definitions are intended to facilitate a translation of the concept of earthquake location from a seismology context to a geographic context. Furthermore, the first global quantitative analysis on the size of the area that is on average exposed to strong ground motion – measured by peak ground acceleration (PGA) – is provided.

scholarly journals Earthquakes on the surface: earthquake location and area based on more than 14500 ShakeMaps

2018 ◽  
Author(s):  
Stephanie Lackner
Keyword(s):  
Ground Motion ◽  
Strong Ground Motion ◽  
Natural Hazard ◽  
Earthquake Location ◽  
Primary Concern ◽  
Ground Acceleration ◽  
Ground Shaking ◽  
The Social ◽  
Quantitative Data Analysis ◽  
Strong Ground

Abstract. Earthquake impacts are an inherently interdisciplinary topic that receives attention from many disciplines. The natural hazard of strong ground motion is the reason why earthquakes are of interest to others than seismologists. However, earthquake shaking data often receives too little attention by the general public and impact research in the social sciences. The vocabulary used to discuss earthquakes has mostly evolved within and for the discipline of seismology. Earthquake communication outside of seismology thus often uses suboptimal concepts that are not of primary concern. This study provides new theoretic concepts as well as novel quantitative data analysis based on shaking data. A dataset of relevant global earthquake ground shaking from 1960 to 2016 based on USGS ShakeMap data has been constructed and applied. Two new definitions of earthquake location (the shaking center and the shaking centroid) based on ground motion parameters are introduced and compared to the epicenter. Furthermore, the first global quantitative analysis on the size of the area that is on average exposed to strong ground motion – measured by peak ground acceleration (PGA) – is provided.

scholarly journals Relationships between macroseismic intensity and peak ground acceleration and velocity for the Vrancea (Romania) subcrustal earthquakes

2021 ◽  
Vol 64 (4) ◽  
pp. SE432
Author(s):  
Iren-Adelina Moldovan ◽  
Angela Petruta Constantin ◽  
Raluca Partheniu ◽  
Bogdan Grecu ◽  
Constantin Ionescu
Keyword(s):  
Ground Motion ◽  
Peak Ground Acceleration ◽  
Strong Ground Motion ◽  
Empirical Relationship ◽  
Macroseismic Intensity ◽  
Ground Acceleration ◽  
Ground Motion Parameters ◽  
Motion Parameters ◽  
Subcrustal Earthquakes ◽  
Strong Ground

The goal of this paper is to develop a new empirical relationship between observed macroseismic intensity and strong ground motion parameters such as peak ground acceleration (PGA) and velocity (PGV) for the Vrancea subcrustal earthquakes. The recent subcrustal earthquakes provide valuable data to examine these relationships for Vrancea seismogenic region. This region is one of the most active seismic zones in Europe and it is well-known for the strong subcrustal earthquakes. We examine the correlation between the strong ground-motion records and the observed intensities for major and moderate earthquakes with Mw ≥ 5.4 and epicentral intensity in the range VI to IX MSK degrees that occurred in Vrancea zone in the period 1977-2009. The empirical relationships between maximum intensity and ground parameters obtained and published by various authors have shown that these parameters do not always show a one-to-one correspondence, and the errors associated with the intensity estimation from PGA/PGV are sometimes +/-2 MSK degree. In the present study, the relation between macroseismic intensity and PGA/PGV will be given both as a mathematical equation, but also as corresponding ground motion intervals. Because of the intensity data spreading and errors related to mathematical approximations, it is necessary to systematically monitor not only the acceleration and velocity but also all the other ground motion parameters. The mathematical relation between these parameters might be used for the rapid assessment of ground shaking severity and potential damages in the areas affected by the Vrancea earthquakes.

scholarly journals Source Model and Simulated Strong Ground Motion of the 2021 Yangbi, China Shallow Earthquake Constrained by InSAR Observations

2021 ◽  
Vol 13 (20) ◽  
pp. 4138
Author(s):  
Yongzhe Wang ◽  
Kun Chen ◽  
Ying Shi ◽  
Xu Zhang ◽  
Shi Chen ◽  
...  
Keyword(s):  
Ground Motion ◽  
Strong Ground Motion ◽  
Surface Deformation ◽  
Source Model ◽  
Seismic Intensity ◽  
Deformation Pattern ◽  
Source Modeling ◽  
Ground Acceleration ◽  
Strong Ground Motion Simulation ◽  
Strong Ground

On 21 May 2021, an Mw 6.1 earthquake, causing considerable seismic damage, occurred in Yangbi County, Yunnan Province of China. To better understand the surface deformation pattern, source characteristics, seismic effect on nearby faults, and strong ground motion, we processed the ascending and descending SAR images using the interferometric synthetic aperture radar (InSAR) technique to capture the radar line-of-sight (LOS) directional and 2.5-dimensional deformation. The source model was inverted from the LOS deformation observations. We further analyzed the Coulomb failure stress (CFS) transfer and peak ground acceleration (PGA) simulation based on the preferred source model. The results suggest that the 2021 Yangbi earthquake was dextral faulting with the maximum slip of 0.9 m on an unknown blind shallow fault, and the total geodetic moment was 1.4 × 1018 Nm (Mw 6.06). Comprehensive analysis of the CFS transfer and geological tectonics suggests that the Dian–Xibei pull-apart basin is still suffering high seismic hazards. The PGA result demonstrates that the seismic intensity of this event reached up to VIII. The entire process from InSAR deformation to source modeling and strong ground motion simulation suggests that the InSAR technique will play an important role in the assessment of earthquake disasters in the case of the shortening of the SAR imaging interval.

scholarly journals ESTIMATION OF SUBSURFACE STRUCTURE BASED ON MICROTREMOR, BORE HOLE OBSERVATIONS AND STOCHASTIC STRONG GROUND MOTION SIMULATIONS IN PALU CITY, CENTRAL SULAWESI, INDONESIA: A VALIDATION AND SENSITIVITY STUDY ON THE 23 JANUARY 2005 (PALU) EARTHQUAKE

2015 ◽  
Vol 6 (2) ◽  
Author(s):  
Pyi Soe Thein ◽  
Subagyo Pramumijoyo ◽  
Wahyu Wilopo ◽  
Agung Setianto ◽  
Kirbani Sri Brotopuspito ◽  
...  
Keyword(s):  
Ground Motion ◽  
Peak Ground Acceleration ◽  
Strong Ground Motion ◽  
Soil Condition ◽  
Fault System ◽  
Earthquake Ground Motion ◽  
Subsurface Structure ◽  
Ground Acceleration ◽  
Central Sulawesi ◽  
Strong Ground

In this study, we investigated the subsurface structure and strong ground motion parameters for Palu City. One of the major structures in Central Sulawesi is the Palu-Koro Fault system. Several powerful earthquakes have struck along the Palu-Koro Fault during recent years, one of the largest of which was an M 6.3 event that occurred on January 23, 2005 and caused several casualties. Following the event, we conducted a microtremor survey to estimate the shaking intensity distribution during the earthquake. From this survey we produced a map of the peak ground acceleration, velocity and ground shear strain in Palu City. We performed single observations of microtremors at 151 sites in Palu City. The results enabled us to estimate the site-dependent shaking characteristics of earthquake ground motion. We also conducted 8-site microtremor array investigation to gain a representative determination of the soil condition of subsurface structures in Palu. From the dispersion curve of array observations, the central business district of Palu corresponds to relatively soil condition with Vs ≤ 300 m/s, the predominant periods due to horizontal vertical ratios (HVSRs) are in the range of 0.4 to 1.8 s and the resonant frequency are in the range of 0.7 to 3.3 Hz. Three boreholes were throughout the basin especially in Palu area to evaluate the geotechnical properties of subsurface soil layers. The depths are varying from 1 m to 30 m. Strong ground motions of the Palu area were predicted based on the empirical stochastic green’s function method. Peak ground acceleration and peak ground velocity becomes more than 0.04 g and 30 kine in some areas, which causes severe damage for buildings in high probability. Keywords: Palu-Koro fault, microtremor, bore holes, peak ground acceleration and velocity.

scholarly journals Earthquake ground shaking hazard assessment for the Lower Hutt and Porirua areas, New Zealand

1992 ◽  
Vol 25 (4) ◽  
pp. 286-302 ◽  
Author(s):  
R. J. Van Dissen ◽  
J. J. Taber ◽  
W. R. Stephenson ◽  
S. Sritheran ◽  
S. A. L. Read ◽  
...  
Keyword(s):  
Ground Motion ◽  
Strong Motion ◽  
Spectral Ratio ◽  
Fine Sand ◽  
Geographic Variations ◽  
Ground Acceleration ◽  
Ground Shaking ◽  
Earthquake Scenarios ◽  
Shear Wave Velocities ◽  
Strong Ground

Geographic variations in strong ground shaking expected during damaging earthquakes impacting on the Lower Hutt and Porirua areas are identified and quantified. Four ground shaking hazard zones have been mapped in the Lower Hutt area, and three in Porirua, based on geological, weak motion, and strong motion inputs. These hazard zones are graded from 1 to 5. In general, Zone 5 areas are subject to the greatest hazard, and Zone 1 areas the least. In Lower Hutt, zones 3 and 4 are not differentiated and are referred to as Zone 3-4. The five-fold classification is used to indicate the range of relative response. Zone 1 areas are underlain by bedrock. Zone 2 areas are typically underlain by compact alluvial and fan gravel. Zone 3-4 is underlain, to a depth of 20 m, by interfingered layers of flexible (soft) sediment (fine sand, silt, clay, peat), and compact gravel and sand. Zone 5 is directly underlain by more than 10 m of flexible sediment with shear wave velocities in the order of 200 m/s or less. The response of each zone is assessed for two earthquake scenarios. Scenario 1 is for a moderate to large, shallow, distant earthquake that results in regional Modified Mercalli intensity V-VI shaking on bedrock. Scenario 2 is for a large, local, but rarer, Wellington fault earthquake. The response characterisation for each zone comprises: expected Modified Mercalli intensity; peak horizontal ground acceleration; duration of strong shaking; and amplification of ground motion with respect to bedrock, expressed as a Fourier spectral ratio, including the frequency range over which the most pronounced amplification occurs. In brief, high to very high ground motion amplifications are expected in Zone 5, relative to Zone 1, during a scenario 1 earthquake. Peak Fourier spectral ratios of 10-20 are expected in Zone 5, relative to Zone 1, and a difference of up to three, possibly four, MM intensity units is expected between the two zones. During a scenario 2 event, it is anticipated that the level of shaking throughout the Lower Hutt and Porirua region will increase markedly, relative to scenario 1, and the average difference in shaking between each zone will decrease.

scholarly journals INCORPORATING DIFFERENT SOURCE RUPTURE CHARACTERISTICS INTO SIMULATIONS OF STRONG GROUND MOTION FROM THE 1867, M7.0 EARTHQUAKE ON THE ISLAND OF LESVOS (NE AEGEAN SEA, GREECE)

2017 ◽  
Vol 43 (4) ◽  
pp. 2135 ◽  
Author(s):  
Z. Roumelioti ◽  
A. Kiratzi
Keyword(s):  
Ground Motion ◽  
Strong Ground Motion ◽  
Order Approximation ◽  
Empirical Relation ◽  
Aegean Sea ◽  
Site Effect ◽  
Eastern Coast ◽  
Ground Acceleration ◽  
Macroseismic Effects ◽  
Strong Ground

We apply the stochastic method for finite-faults (Beresnev and Atkinson, 1997, 1998) to simulate strong ground motion acceleration from the 1867 earthquake that devastated the Island of Lesvos in NE Aegean Sea. Recent geological data are taken into account to construct realistic models of the earthquake source, while a first-order approximation of the site effect variation throughout the entire island of Lesvos is achieved following an empirical approach suggested by Wald and Allen (2007). We test several source models including different segments of the Agia Paraskevi fault, which is most probably the seismogenic fault of the 1867 earthquake. Stronger ground motion is predicted in the central part of the island, i.e. around the assumed seismogenic structure. A significant site effect is evident along the eastern coast of Lesvos, where the capital of Mytilene lies, strongly hit by the 1867 earthquake, and around the gulfs of Kalloni and Geras in the south and southeast parts of the island. Synthetic peak ground acceleration values are converted to macroseismic intensities through an empirical relation and discussed in comparison with available reports on the macroseismic effects of the 1867 earthquake.

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

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

<p>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.</p>

scholarly journals Prediction and evaluation of nonlinear site response with potentially liquefiable layers in the area of Nafplion (Peloponnesus, Greece) for a repeat of historical earthquakes

2010 ◽  
Vol 10 (11) ◽  
pp. 2281-2304 ◽  
Author(s):  
V. K. Karastathis ◽  
G. A. Papadopoulos ◽  
T. Novikova ◽  
Z. Roumelioti ◽  
P. Karmis ◽  
...  
Keyword(s):  
Ground Motion ◽  
Strong Ground Motion ◽  
Site Response ◽  
Soft Soil ◽  
Soil Layer ◽  
Ground Acceleration ◽  
Nonlinear Site Response ◽  
Strong Ground Motion Simulation ◽  
Scenario Earthquakes ◽  
Strong Ground

Abstract. We examine the possible non-linear behaviour of potentially liquefiable layers at selected sites located within the expansion area of the town of Nafplion, East Peloponnese, Greece. Input motion is computed for three scenario earthquakes, selected on the basis of historical seismicity data, using a stochastic strong ground motion simulation technique, which takes into account the finite dimensions of the earthquake sources. Site-specific ground acceleration synthetics and soil profiles are then used to evaluate the liquefaction potential at the sites of interest. The activation scenario of the Iria fault, which is the closest one to Nafplion (M=6.4), is found to be the most hazardous in terms of liquefaction initiation. In this scenario almost all the examined sites exhibit liquefaction features at depths of 6–12 m. For scenario earthquakes at two more distant seismic sources (Epidaurus fault – M6.3; Xylokastro fault – M6.7) strong ground motion amplification phenomena by the shallow soft soil layer are expected to be observed.

Determination of Strong Ground Motion in Complex Structures Using Dynamic Raytracing.

1983 ◽  
Author(s):  
G. R. Mellman ◽  
D. M. Hadley ◽  
R. S. Hart ◽  
S. K. Kaufman
Keyword(s):  
Ground Motion ◽  
Strong Ground Motion ◽  
Complex Structures ◽  
Strong Ground
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