Reliability of Ambient Noise Horizontal-to-Vertical Spectral Ratio in Urban Environments: The Case of Thessaloniki City (Northern Greece)

2005 ◽  
Vol 162 (5) ◽  
pp. 891-912 ◽  
Author(s):  
A. A. Panou ◽  
N.P. Theodulidis ◽  
P.M. Hatzidimitriou ◽  
A.S. Savvaidis ◽  
C.B. Papazachos
Keyword(s):  
Ambient Noise ◽  
Spectral Ratio ◽  
Urban Environments ◽  
Northern Greece

scholarly journals AMBIENT NOISE HORIZONTAL-TO-VERTICAL SPECTRAL RATIO FOR ASSESSING SITE EFFECTS IN URBAN ENVIRONMENTS: THE CASE OF THESSALONIKI CITY ( NORTHERN GREECE )

2004 ◽  
Vol 36 (3) ◽  
pp. 1467 ◽  
Author(s):  
A. A. Panou ◽  
N. Theodulidis ◽  
P. M. Hatzidimitriou ◽  
C. B. Papazachos ◽  
K. Stylianidis
Keyword(s):  
Fundamental Frequency ◽  
Ambient Noise ◽  
Spectral Ratio ◽  
Urban Environments ◽  
Macroseismic Data ◽  
Northern Greece ◽  
Contour Maps ◽  
Noise Measurements ◽  
The City ◽  
Amplitude Level

250 ambient noise measurements were performed in a dense grid (about 150mX150m) covering the historical center of the city of Thessaloniki (Northern Greece), that was strongly affected by the 20/6/1978 (M=6.5) damaging earthquake. The data were processed using the method of horizontal- to-vertical (H/V) spectral ratio (Nogoshi and Igarashi, 1971; Nakamura, 1989). In order to evaluate diurnal and seasonal variation (summer - winter) of the ambient noise H/V spectral ratio, systematic measurements were performed in eight sites. The fundamental frequency (fo) and the corresponding H/V amplitude level (Ao) from the ambient noise H/V spectral ratio for each site were calculated. Spatial interpolation of the fundamental frequency (fo) and the corresponding H/V amplitude level (Ao) was attempted between all points and respective contour maps were produced. Diurnal variation of the ambient noise H/V spectral ratio showed that it is preferable to perform measurements during the calm hours of a day, when manmade noise is relatively low. However, no systematic seasonal fluctuation effect on the ambient noise H/V spectral ratio was identified for the city of Thessaloniki. Contour maps of both fundamental frequency (fo) and corresponding H/V amplitude level (Ao) were compared versus the macroseismic data of the 1978 earthquake (Leventakis, 2003), as well as with related geological (IGME, 1978) and geotechnical (Anastasiadis et al., 2001) studies for the same area. Damage distribution due to 20/6/1978 earthquake (Penelis et al., 1985) was also converted to EMS_98 (European Macroseismic Scale, 1998). For seventy buildings, made of reinforced concrete, we have also compared the obtained results with the dynamic amplification of the buildings (Ubuilding) at the fundamental soil frequency (fo). The results encourage the use of ambient noise measurements along with the (H/V) spectral ratio technique as a nonexpensive and fast tool in microzonation studies to be carried out in urban environments.

scholarly journals Multiple Geophysical Techniques for Investigation and Monitoring of Sobradinho Landslide, Brazil

2019 ◽  
Vol 11 (23) ◽  
pp. 6672 ◽  
Author(s):  
Yawar Hussain ◽  
Martin Cardenas-Soto ◽  
Salvatore Martino ◽  
Cesar Moreira ◽  
Welitom Borges ◽  
...  
Keyword(s):  
Ambient Noise ◽  
Geophysical Methods ◽  
Spectral Ratio ◽  
Dynamic Monitoring ◽  
Physical Parameters ◽  
Sliding Surface ◽  
Time Duration ◽  
Geophysical Techniques ◽  
Short Time

Geophysical methods have a varying degree of potential for detailed characterization of landslides and their dynamics. In this study, the application of four well-established seismic-based geophysical techniques, namely Ambient Noise Interferometry (ANI), Horizontal to Vertical Spectral Ratio (HVSR), Multi-Channel Analysis of Surface Waves (MASW) and Nanoseismic Monitoring (NM), were considered to examine their suitability for landslide characterization and monitoring the effect of seasonal variation on slope mass. Furthermore, other methods such as Ground Penetrating Radar (GPR) and DC Resistivity through Electrical Resistivity Tomography (ERT) were also used for comparison purpose. The advantages and limitations of these multiple techniques were exemplified by a case study conducted on Sobradinho landslide in Brazil. The study revealed that the geophysical characterization of the landslide using traditional techniques (i.e., GPR, ERT and MASW) were successful in (i) the differentiation between landslide debris and other Quaternary deposits, and (ii) the delineation of the landslide sliding surface. However, the innovative seismic based techniques, particularly ambient noise based (HVSR and ANI) and emitted seismic based (NM), were not very effective for the dynamic monitoring of landslide, which might be attributed to the short-time duration of the data acquisition campaigns. The HVSR was also unsuccessful in landslide site characterization i.e., identification of geometry and sliding surface. In particular, there was no clear evidence of the light seasonal variations, which could have been potentially detected from the physical parameters during the (short-time) ambient noise and microseismic acquisition campaigns. Nevertheless, the experienced integration of these geophysical techniques may provide a promising tool for future applications.

Estimation of Site Dynamic Characteristics from Ambient Noise Measurements Using HVSR Method in Microzonation Study: Senggarang, Batu Pahat, Malaysia

2014 ◽  
Vol 931-932 ◽  
pp. 803-807 ◽  
Author(s):  
Ahmad Fahmy Kamarudin ◽  
Mohd Effendi Daud ◽  
Zainah Ibrahim ◽  
Ibrahim Azmi ◽  
Mohamad Khairani Yub ◽  
...  
Keyword(s):  
Dynamic Characteristics ◽  
Ambient Noise ◽  
Hazard Analysis ◽  
Resonance Effect ◽  
Spectral Ratio ◽  
Boundary Area ◽  
Contour Maps ◽  
The North ◽  
Hvsr Method ◽  
Noise Measurements

Site dynamic characteristics evaluation of fundamental ground frequency, Fo and amplification factor, Ao in Senggarang region were presented in 2D and 3D contour maps (microzonation maps) based on the ambient noise measurements carried out using Lennartz 1 Hz tri-axial seismometer sensors. Reliability of Fo and Ao determined from the ambient noise technique has become the main key components in seismic hazard analysis, resonance effect assessment, predictions of sedimentary layer and shear wave velocity, through cheaper, non-destructive and quick methodology. 73 points of ambient noise records were analyzed using Horizontal-to-Vertical Spectral Ratio (HVSR) method in the boundary area of 800 m x 800 m with the grid spacing of 100 m x 100 m. Significant peaks of mean HVSR curves were checked against the criterions proposed by the SESAME guideline. Slight difference of the Fo contours pattern between the North-South (NS) and the East-West (EW) directions was observed, but vice versa to the Ao contours between both directions. Significant peaks of Fo values were distributed from 1.61 to 6.35 Hz, whereas the Ao values were found from 3.18 to 9.39. Wide gap between the ranges of Fo and Ao in respective direction have shown to the variation of sediment thicknesses. Meanwhile, dominance shape of significant peak from the HVSR curves may indicate to a large velocity contrast presence underneath the ground surfaces.

Shallow velocity structure using joint inversion of array and h/v spectral ratio of ambient noise: The case of Mula town (SE of Spain)

2007 ◽  
Vol 27 (10) ◽  
pp. 907-919 ◽  
Author(s):  
A. García-Jerez ◽  
M. Navarro ◽  
F.J. Alcalá ◽  
F. Luzón ◽  
J.A. Pérez-Ruiz ◽  
...  
Keyword(s):  
Ambient Noise ◽  
Velocity Structure ◽  
Joint Inversion ◽  
Spectral Ratio ◽  
Shallow Velocity Structure

scholarly journals Near-surface structure from ambient-noise tomography and horizontal-to-vertical spectral ratio beneath the Nankou-Sunhe fault

2020 ◽  
Vol 33 (5-6) ◽  
pp. 232-238
Author(s):  
Yuting Zhang ◽  
◽  
Hongyi Li ◽  
Yanzhen Li ◽  
Zhijie Wei ◽  
...  
Keyword(s):  
Surface Structure ◽  
Ambient Noise ◽  
Spectral Ratio ◽  
Ambient Noise Tomography ◽  
Near Surface

scholarly journals PEMETAAN WILAYAH RAWAN BENCANA BERDASARKAN DATA IKROSEISMIK MENGGUNAKAN TDS ( Time Digital Seismograph ) Tipe 303 S ( Studi Kasus : Kampus I UIN Maulana Malik Ibrahim Malang dan Sekitarnya )

2012 ◽  
Author(s):  
Irjan, Ahmad Bukhori
Keyword(s):  
Ambient Noise ◽  
Spectral Ratio

Telah dilakukan penelitian tentang mikrozonasi seismik di kampus I UIN Maulana  Malik Ibrahim  Malang  dan  sekitarnya.  penelitian  yang  dilakukan  oleh  penulis  adalah  penelitian  awal mikrozonasi  di  wilayah  kampus  I  UIN  Maulana  Malik  Ibrahim  Malang  dan  sekitarnya  untuk mengatahui  spektral  rasio  H/V(horizontal  vertikal)  sehingga  dapat  diketahui  tingkat  kerawanan kerusakan  akibat   gempabumi   yang   dapat   digunakan   dalam  mitigasi   bencana   alam,   terutama gempabumi.  Mikrotremor  merupakan  vibrasi  lemah  di  permukaan  bumi  yang  berlangsung  terus menerus akibat adanya sumber getar seperti aktivitas manusia, industri dan lalu lintas. Sumber-sumber lain seperti interaksi angin, bangunan, arus laut dan gelombang laut periode panjang juga merupakan sumber  mikrotremor.  Penelitian  ini  dilakukan  dengan  menggunakan  metode  HVSR  (Horizontal Vertical Spectral Ratio) atau A dengan merekam ambient noise atau getaran alami yang timbul dari alam di kampus I UIN Maulana Malik Ibrahim Malang dan sekitarnya akibat  gempabumi. Hal ini akan berguna untuk melihat karakteristik lapisan sedimen seperti frekuensi dominan (   ) sehingga efek geologi dan topograpi dapat dikurangi ketika bencana terjadi. Berdasarkan hasil  yang diperoleh dari penelitian, antara    dan A memperlihatkan bahwa potensi kerusakan akibat gempabumi adalah cukup rendah. Hal ini bersesuaian dengan nilai indeks kerentanan seismik (Kg) yang berkisar antara 0,055 hingga 2,856. Dari analisis ketiga parameter ditemukan potensi yang tinggi di sekitar wilayah titik 5 dan 4 yang memiliki nilai indeks kerentanan seismik (Kg) sebesar 31,205 dan 76,097.<br /><br /><br /><br />

scholarly journals On the use of the coda of seismic noise autocorrelations to compute H/V spectral ratios

2019 ◽  
Vol 220 (3) ◽  
pp. 1956-1964 ◽  
Author(s):  
F N Tchawe ◽  
B Froment ◽  
M Campillo ◽  
L Margerin
Keyword(s):  
Ambient Noise ◽  
Sedimentary Basin ◽  
Temporal Stability ◽  
Spectral Ratio ◽  
Spectral Ratios ◽  
Data Set ◽  
Underlying Assumption ◽  
Seismic Ambient Noise ◽  
Physical Information ◽  
Local Medium

SUMMARY The horizontal to vertical spectral ratio (HVSR) of seismic ambient noise has been proven to be a fast and efficient method for characterizing the 1-D resonance frequency of the local subsurface in a practical framework. Over the last decades, theories have been developed in order to extend the exploitation of HVSR beside the frequency of its first peak, notably the diffuse field assumption (DFA) which links the HVSR to the Green’s function of the local medium assuming the diffuseness of the seismic ambient noise wavefield. However, the underlying assumption of the seismic ambient noise being a diffuse, equipartitioned field may not be satisfied under certain circumstances. In order to exploit the contribution of scattering in forging diffuse wave fields, we leverage the advantages of coda waves and present a novel procedure for computing the HVSR, using the coda part of ambient noise correlations. We applied this technique to data gathered at the plio-quaternary sedimentary basin of Argostoli, Greece. Results on this data set show the potential of the method to improve the temporal stability of the HVSR measurements compared to the classical computation, and the fit with the theoretical HVSR curve derived from the DFA theory. These results suggest that this procedure could help in extracting physical information from the HVSR and thus could lead to an extended use of these measurements to characterize the mechanical properties of the medium.

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