scholarly journals Geospatial Assessment of the Post-Earthquake Hazard of the 2017 Pohang Earthquake Considering Seismic Site Effects

2018 ◽  
Vol 7 (9) ◽  
pp. 375 ◽  
Author(s):  
Han-Saem Kim ◽  
Chang-Guk Sun ◽  
Hyung-Ik Cho
Keyword(s):  
Site Effects ◽  
Focal Depth ◽  
Earthquake Hazard ◽  
Earthquake Damage ◽  
Site Classification ◽  
Topographical Effects ◽  
Seismic Site Effects ◽  
Moderate Earthquake ◽  
Seismic Amplification ◽  
Earthquake Moment

The 2017 Pohang earthquake (moment magnitude scale: 5.4) was South Korea’s second strongest earthquake in decades, and caused the maximum amount of damage in terms of infrastructure and human injuries. As the epicenters were located in regions with Quaternary sediments, which involve distributions of thick fill and alluvial geo-layers, the induced damages were more severe owing to seismic amplification and liquefaction. Thus, to identify the influence of site-specific seismic effects, a post-earthquake survey framework for rapid earthquake damage estimation, correlated with seismic site effects, was proposed and applied in the region of the Pohang earthquake epicenter. Seismic zones were determined on the basis of ground motion by classifying sites using the multivariate site classification system. Low-rise structures with slight and moderate earthquake damage were noted to be concentrated in softer sites owing to the low focal depth of the site, topographical effects, and high frequency range of the mainshocks.

scholarly journals Correction: Kim, H.; et al. Geospatial Assessment of the Post-Earthquake Hazard of the 2017 Pohang Earthquake Considering Seismic Site Effects. ISPRS Int. J. Geo-Inf. 2018, 7, 375

2019 ◽  
Vol 8 (2) ◽  
pp. 62
Author(s):  
Han-Saem Kim ◽  
Chang-Guk Sun ◽  
Hyung-Ik Cho
Keyword(s):  
Site Effects ◽  
Earthquake Hazard ◽  
Seismic Site Effects

We have recently been made aware of errata and omissions in the introduction section for describing the seismological characteristics of the 2017 Pohang earthquake as stated in the title of this article, which was recently published in ISPRS [...]

scholarly journals Geo-Proxy-Based Site Classification for Regional Zonation of Seismic Site Effects in South Korea

2018 ◽  
Vol 8 (2) ◽  
pp. 314 ◽  
Author(s):  
Chang-Guk Sun ◽  
Han-Saem Kim ◽  
Hyung-Ik Cho
Keyword(s):  
South Korea ◽  
Site Effects ◽  
Site Classification ◽  
Seismic Site Effects

Local Seismic site effects estimated by detailed seismic surveys: the case of Castelnuovo village (L’Aquila Basin, central Italy)

2021 ◽  
Author(s):  
Marco Spadi ◽  
Marco Tallini ◽  
Matteo Albano ◽  
Domenico Cosentino ◽  
Marco Nocentini ◽  
...  
Keyword(s):  
Cross Sections ◽  
Site Effects ◽  
Dynamic Properties ◽  
Central Italy ◽  
Earthquake Hazard ◽  
Small Scale ◽  
Seismic Site Effects ◽  
New Findings ◽  
Subsoil Model ◽  
Observed Damage

<p>Assessing seismic site effects is essential in earthquake hazard studies. Local seismic amplification is strongly related to the site stratigraphy and topography, the dynamic properties of the subsoil deposits, and the earthquake features. The evaluation of these factors is mandatory to achieve a consistent model of the seismic hazard at small scale. Here we discuss the case of Castelnuovo village (L’Aquila, central Italy). Located on a small ridge, approximately 60 m higher than the valley floor, the village was heavily struck by April 6, 2009, M<sub>w</sub> 6.3 L’Aquila earthquake, with catastrophic collapse of several buildings. Previous studies ascribed the observed damage to the presence of shallow caves beneath the buildings or to the topographic amplification.</p><p>In this work, an updated and detailed subsoil model for Castelnuovo site has been provided, based updated geological surveys, such as borehole logs and geophysical data consisting in microtremor measurements and down-hole.</p><p>These measurements identified resonant frequencies occurring in the range of 0.7-3.0 Hz. These frequency peaks are related to the presence of a velocity contrast at depth between the San Nicandro silts and the Madonna della Neve breccias, as indicated by the performed deep boreholes. Thanks to analytical, numerical, and geostatistical techniques, we identified the main impedance contrast at approximately 210 m depth from the top of the hill, much deeper than previous studies. These new findings allowed to create an accurate and consistent subsoil model summarized by two geological cross-sections of the Castelnuovo ridge, showing that the seismic site effects at the Castelnuovo village are mainly related to stratigraphic amplification.</p>

Correlation between earthquake damage and seismic site effects: The study case of Lentini and Carlentini, Italy

2018 ◽  
Vol 240 ◽  
pp. 149-162 ◽  
Author(s):  
F. Panzera ◽  
G. Lombardo ◽  
S. Imposa ◽  
S. Grassi ◽  
S. Gresta ◽  
...  
Keyword(s):  
Site Effects ◽  
Earthquake Damage ◽  
Seismic Site Effects ◽  
Study Case

scholarly journals Shallow shear-wave reflection seismics in the tsunami struck Krueng Aceh River Basin, Sumatra

2008 ◽  
Vol 14 ◽  
pp. 135-140 ◽  
Author(s):  
U. Polom ◽  
I. Arsyad ◽  
H.-J. Kümpel
Keyword(s):  
High Resolution ◽  
Shear Wave ◽  
Site Effects ◽  
Wave Reflection ◽  
P Wave ◽  
Site Classification ◽  
Seismic Site Effects ◽  
Reflection Seismics ◽  
The City ◽  
Banda Aceh

Abstract. As part of the project "Management of Georisk" (MANGEONAD) of the Federal Institute for Geosciences and Natural Resources (BGR), Hanover, high resolution shallow shear-wave reflection seismics was applied in the Indonesian province Nanggroe Aceh Darussalam, North Sumatra in cooperation with the Government of Indonesia, local counterparts, and the Leibniz Institute for Applied Geosciences, Hanover. The investigations were expected to support classification of earthquake site effects for the reconstruction of buildings and infrastructure as well as for groundwater exploration. The study focussed on the city of Banda Aceh and the surroundings of Aceh Besar. The shear-wave seismic surveys were done parallel to standard geoengineering investigations like cone penetrometer tests to support subsequent site specific statistical calibration. They were also partly supplemented by shallow p-wave seismics for the identification of (a) elastic subsurface parameters and (b) zones with abundance of groundwater. Evaluation of seismic site effects based on shallow reflection seismics has in fact been found to be a highly useful method in Aceh province. In particular, use of a vibratory seismic source was essential for successful application of shear-wave seismics in the city of Banda Aceh and in areas with compacted ground like on farm tracks in the surroundings, presenting mostly agricultural land use areas. We thus were able to explore the mechanical stiffness of the subsurface down to 100 m depth, occasionally even deeper, with remarkably high resolution. The results were transferred into geotechnical site classification in terms of the International Building Code (IBC, 2003). The seismic images give also insights into the history of the basin sedimentation processes of the Krueng Aceh River delta, which is relevant for the exploration of new areas for construction of safe foundations of buildings and for identification of fresh water aquifers in the tsunami flooded region.

Evaluation of Peak Ground Acceleration and Response Spectra Considering the Local Site Effects

2010 ◽  
Vol 1 (1) ◽  
pp. 25-41 ◽  
Author(s):  
T. G. Sitharam ◽  
K. S. Vipin
Keyword(s):  
Seismic Hazard ◽  
Peak Ground Acceleration ◽  
Site Effects ◽  
Response Spectra ◽  
Probabilistic Logic ◽  
Site Classification ◽  
Ground Acceleration ◽  
Entire Study ◽  
Local Site Effects ◽  
Local Site

The local site effects play an important role in the evaluation of seismic hazard. The proper evaluation of the local site effects will help in evaluating the amplification factors for different locations. This article deals with the evaluation of peak ground acceleration and response spectra based on the local site effects for the study area. The seismic hazard analysis was done based on a probabilistic logic tree approach and the peak horizontal acceleration (PHA) values at the bed rock level were evaluated. Different methods of site classification have been reviewed in the present work. The surface level peak ground acceleration (PGA) values were evaluated for the entire study area for four different site classes based on NEHRP site classification. The uniform hazard response spectrum (UHRS) has been developed for the city of Bangalore and the details are presented in this work.

scholarly journals Seismic site effects in the Red Zone of Amatrice hill detected via the mutual sustainment of experimental and computational approaches

2020 ◽  
Vol 18 (5) ◽  
pp. 1955-1984
Author(s):  
Gerardo Grelle ◽  
Elisa Gargini ◽  
Johann Facciorusso ◽  
Rosalba Maresca ◽  
Claudia Madiai
Keyword(s):  
Site Effects ◽  
Computational Approaches ◽  
Seismic Site Effects
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