Identification of pre-seismic anomalies of soil radon-222 signal using Hilbert–Huang transform

Chowdhury, S.; Deb, Argha; Nurujjaman, Md.; Barman, Chiranjib

doi:10.1007/s11069-017-2835-1

Cited by 21 publications

(10 citation statements)

References 65 publications

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“…In the literature, anomalies are observed also for earthquakes as small as M ≈ 3, but the most common observations are related to earthquake with M > 4.5. Anomalies could anticipate, or follow, a local earthquake of hours, days, or even months and may vary in term of rate, absolute amplitude, and temporal response (Chowdhury et al., 2017; Deb et al., 2016; Friedmann, 2012; Piersanti et al., 2016; Papachristodoulou et al., 2019; Tarakçı et al., 2014; Weinlich et al., 2006; Zafrir et al., 2016).…”

Section: Discussionmentioning

confidence: 99%

Long‐Term Monitoring and Characterization of Soil Radon Emission in a Seismically Active Area

D’Alessandro

Scudero

Siino

et al. 2020

Geochem Geophys Geosyst

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Radon (222Rn) is a radioactive gas, which originates everywhere in rocks of Earth's crust through a process of natural decay of other radioactive elements. The monitoring of soil radon can be useful to address a multitude of geological and environmental issues. However, some difficulties arise when trying to use radon as earthquake precursor because the earthquake‐related anomaly cannot be easily and univocally discriminated from other anomalies of different origin. To explore the relationship between soil radon emission and seismicity, a local network is operating in southeastern Sicily (Italy). Its peculiarities are the uniform geological condition of the monitoring sites and the long data record with simultaneous measures of radon and the main climate variables. In this paper, we applied continuous wavelet transformation to a ≈ 3.5 years long soil radon time series to detect periodic variations. Results indicate the occurrence of cycles at annual, semiannual, and monthly periodicity, which are ascribable to the effects of the climatic‐environmental parameters. The periodic components have been modeled and the signal conveniently filtered. We show as the characterization of the long‐term behavior of radon signals is essential to recognize anomalies in radon emission, which can be related to geological/environmental phenomena. The methodology proposed in this work provides a reliable characterization of the radon time series and can be applied at various spatial/temporal scales, depending on the scientific objectives to be achieved. This approach can also represent the base for further analysis like the investigation of the modulation between the periodic components and short‐term forecasts.

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Section: Discussionmentioning

confidence: 99%

Long‐Term Monitoring and Characterization of Soil Radon Emission in a Seismically Active Area

D’Alessandro

Scudero

Siino

et al. 2020

Geochem Geophys Geosyst

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“…The IMFs satisfy the following two conditions; i) the number of extrema and the number of zero crossing must be equal or differ by one; and ii) mean values of the envelope, defined by the local maxima and local minima, for each point are zero. The IMF is calculated in the following way [23,25] Once the conditions are satisfied, the process terminates, and h is stored as the first IMF. The second IMF is calculated repeating the above steps (a)-(c) from the data set…”

Section: Methods Of Analysismentioning

confidence: 99%

Time Scales and Characteristics of Stock Markets in Different Investment Horizons

Mahata

Nurujjaman

2020

Front. Phys.

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“…However, previous study works show that the Fourier transform is only applicable to linear and stationary data analysis [16,17]. Compared with the Fourier transform, the Hilbert-Huang transform (HHT) can be used for nonlinear and nonstationary signal and has been widely used in analyzing seismic signals in recent years [17][18][19][20]. However, empirical mode decomposition (EMD) of HHT essentially belongs to recursive modal decomposition.…”

Section: Introductionmentioning

confidence: 99%

Seismic Signal-Based Investigation on the Disaster Differences between 2021 Yangbi Ms 6.4 Earthquake and 2014 Ms 6.5 Ludian Earthquake in Yunnan Province, China

Chen

Che

Wang

et al. 2022

Shock and Vibration

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An Ms 6.4 earthquake occurred in Yangbi County, Yunnan Province, on May 21, 2021. The magnitude is only 0.1 difference when compared with the 2014 Ms 6.5 earthquake in Ludian County, Yunnan Province, but the disasters show a big difference. Seismic signal includes the comprehensive information of source, propagation path, and site effect, which directly reflect the effect of the earthquake on the ground. The study mainly investigated the difference between seismic signals of two events in time domain and time-frequency-energy space based on variational mode decomposition and Hilbert transform to clarify the reasons for disaster differences. Most damaged buildings are column-and-tie timber structures with Earth walls with local collapse or vertical crack at the corner of the Earth wall in the Yangbi earthquake. Multistorey buildings are intact, and a few small landslides are triggered, whereas, in the Ludian earthquake, multistorey buildings with the frame structure and masonry structure occurred with serious X-type cracking, large interlayer displacement, and even complete collapse, and large landslides with length about 165 m are triggered. 53LLT and 53YBX are two strong motion stations in the Ludian earthquake and Yangbi earthquake, respectively, and are near the disaster investigation points. Peak ground acceleration in 53LLT is up to 949.2 cm/s2, which is larger than 720.3 cm/s2 in 53YBX, and the duration in 53LLT is longer than 53YBX. The instantaneous energy of 53YBX is concentrated within 0–10 Hz and 10–20 Hz, respectively; however, the instantaneous energy of 53LLT is concentrated at 5 Hz. Cumulative energy of 53YBX is mainly distributed at 0–5 Hz and 10–20 Hz, which is around the natural frequency of column-and-tie timber structure, while the energy of 53LLT is concentrated at 1.6 Hz and is much greater than other stations. Thus, large energy in high frequency caused the instantaneous and cumulative damage to short-period structures in Yangbi County and may cause the resonance of column-and-tie timber structure, and large energy in low frequency caused the instantaneous and cumulative damage to long-period structures of Longtou Village in Ludian earthquake. The result is meaningful to understanding the seismic disasters from the characteristics of seismic signals and can provide a reference for the seismic design of structures.

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Identification of pre-seismic anomalies of soil radon-222 signal using Hilbert–Huang transform

Cited by 21 publications

References 65 publications

Long‐Term Monitoring and Characterization of Soil Radon Emission in a Seismically Active Area

Long‐Term Monitoring and Characterization of Soil Radon Emission in a Seismically Active Area

Time Scales and Characteristics of Stock Markets in Different Investment Horizons

Seismic Signal-Based Investigation on the Disaster Differences between 2021 Yangbi Ms 6.4 Earthquake and 2014 Ms 6.5 Ludian Earthquake in Yunnan Province, China

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