Seismo ionospheric anomalies before the 2007 M7.7 Chile earthquake from GPS TEC and DEMETER

Shah, Munawar; Tariq, M. Arslan; Ahmad, Junaid; Naqvi, Najam Abbas; Jin, Shuanggen

doi:10.1016/j.jog.2019.05.004

Cited by 45 publications

(27 citation statements)

References 35 publications

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“…The MODIS LST anomalies need to study for other terrestrial EQs in different parts of the world. There are different studies about EQ anomalies from MODIS and other satellites [28][29][30][31][32][33][34][35][36]. However, the results can be better for those EQs with homogenous terrain and no heterogeneity in the terrain like Mirpur Pakistan EQ.…”

Section: B Discussionmentioning

confidence: 99%

Possible Atmosphere and Ionospheric Anomalies of the 2019 Pakistan Earthquake Using Statistical and Machine Learning Procedures on MODIS LST, GPS TEC, and GIM TEC

Hafeez¹,

Shah²,

Ehsan³

et al. 2021

IEEE J. Sel. Top. Appl. Earth Observations Remote Sensing

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Identifying atmospheric and ionospheric anomalies based on remote sensing satellites has contributed highly to develop the hypothesis of lithosphere-atmosphere-ionosphere coupling (LAIC) over the Earthquake (EQ) epicenter during the seismic preparation period. This paper has investigated the variations of potential EQ precursor in daytime and nighttime Land Surface Temperature (LST) before and after the 2019 Pakistan EQ from MODIS (Moderate Resolution Imaging Spectroradiometer) satellite. The nighttime LST values of MODIS exhibit temporal anomalies during nighttime period within a time window of 5 days before and after the main shock day. Furthermore, the LST values predicted by Artificial Neural Network (ANN) validate the significant enhancement in nighttime time series of MODIS. The nighttime LST anomalies obtained from the observation and ANN prediction are more than 20% and 7% of normal distribution beyond the confidence bounds, respectively, within 5 days after the main shock. Likewise, the ionospheric anomaly from daily Total Electron Content (TEC) values at Sukkur Global Positioning System (GPS) station confirms the EQ associated ionospheric perturbations on the day after the main shock. The Global Ionospheric Maps (GIMs) also show the TEC anomalies during 1000-1400 LT on September 25, 2019.

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Section: B Discussionmentioning

confidence: 99%

Possible Atmosphere and Ionospheric Anomalies of the 2019 Pakistan Earthquake Using Statistical and Machine Learning Procedures on MODIS LST, GPS TEC, and GIM TEC

Hafeez¹,

Shah²,

Ehsan³

et al. 2021

IEEE J. Sel. Top. Appl. Earth Observations Remote Sensing

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“…Lin et al (2019a) predicted TEC precursors constituting spatial TEC multi-precursors (STMPs) prior to the China Ludian earthquake at 08:30:13 UT on August 3, 2014 (M w = 6.1) using Kernel-based two-dimensional principal component analysis through examination of the ionospheric twodimensional TEC variations obtained from the NASA Global Differential Global Positioning System network. Shah et al (2019) detected TEC variations in the ionosphere associated with the M w 7.7 Chile earthquake on November 14, 2007. However, they did not use the neural network (NN) as their tool.…”

Section: Introductionmentioning

confidence: 94%

“…Many studies have researched the total electron content (TEC) anomalies associated with large earthquakes (Wang et al, 2015;Liu et al, 2016;Tao et al, 2017;Ho et al, 2018;Lin et al, 2019a;Shah et al, 2019). Wang et al…”

Section: Introductionmentioning

confidence: 99%

Detecting Total Electron Content Precursors Before Earthquakes by Examining Total Electron Content Images Based on Butterworth Filter in Convolutional Neural Networks

Lin

Chiou

2020

IEEE Access

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Taiwan Standard Time [TST]) as training images (inputs) were used to create two convolutional neural network (CNN) models. However, splitting the TEC maps of the three time periods into daily TEC images caused wedge effects. The wedge effects were reduced using a low-pass filter called the Butterworth filter. This resulted in clearer TEC precursors for earthquakes, facilitating the identification of earthquakes of magnitude M w ≥ 5.0 that exhibited associated TEC precursors during three periods, particularly for the Chi-Chi earthquake of September 21, 1999. The results of this study were compared with those of Lin et al. (2001) and Lin (2010) associated with the Chi-Chi earthquake. Simultaneously, two CNN models that were developed were verified to be rational due to the high accuracy of their predictions. These two models were used to verify each other's accuracies and to demonstrate the reliability of the method in this study. Therefore, statistical analysis was not the aim. The final outputs of the two CNN model were defined as similarities. Similarities, which are larger than 0.5, were defined as TEC precursors of earthquakes. TEC precursors described as temporal TEC multi-precursors (TTMPs) by Zoran et al. (2018) were detectable on the 1st, 3rd, and 4th days (that is, on September 17, 18, and 20, 1999, respectively) prior to the Chi-Chi earthquake of September 21, 1999. These results are consistent with those of Liu et al. (2001) and Lin (2010). A TEC precursor on May 13, 2003, (TST) was detectable 2 days prior to the earthquake on May 15, 2003, (TST) with the magnitude (M w) of 5.52. The low standard deviation (STD) and mean square error (MSE) confirm the reliability of both CNN models. Regarding mechanical principles, the TTMPs related to the Chi-Chi earthquake were caused by an electric field (Liu et al., 2001). The cause of the TEC precursor on May 13, 2003, prior to the earthquake on May 15, 2003, was an argument without any corresponding study for comparison.

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“…Similarly, reports are also available on the implementation of different statistical methods for delineating abnormal TEC values before the main shock. For example, (Shah et al, 2019a) statistically examined ionospheric abnormality within 10 days before the impending earthquake from the analysis in GPS and DEMETER values. Furthermore, they observed profound variations in ionospheric parameters (electron density and electron temperature) on earthquake latitudinal axis as compared to its conjugate axis.…”

Section: Introductionmentioning

confidence: 99%

Possible Seismo Ionospheric Anomalies before the 2016 Mw 7.6 Chile Earthquake from GPS TEC, GIM TEC and Swarm Satellites

Rahman¹

2020

Nat. App. Sci. Int. J.

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The recent advances in space based ionospheric measurements can help to investigate seismic precursors before earthquake with multi-parameter observations and more dedicated instrumentations. In this paper, seismo ionospheric anomalies before the December 25, 2016, Mw 7.6, Chile earthquake are investigated in Total Electron Content (TEC) and Global Ionosphere Map (GIM). The temporal TEC from GPS stations and GIM show enhancement during 5- 10 days (local daytime) before main shock. Similarly, spatial TEC confirms abnormal dense cloud at LT=12h-14h on December 21, 2016, that lingers over the epicenter of Chile earthquake. On the other hand, the geomagnetic indices show Dst < -50nT of low intensity variation. Similarly, Kp > 3 on December 21, 2016 within 5-10 days before the Mw 7.6. This study emphasizes that the ionosphere anomalies may not be the possible association of earthquakes induced variation but it is due to the active storm conditions (Kp>3).

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Seismo ionospheric anomalies before the 2007 M7.7 Chile earthquake from GPS TEC and DEMETER

Cited by 45 publications

References 35 publications

Possible Atmosphere and Ionospheric Anomalies of the 2019 Pakistan Earthquake Using Statistical and Machine Learning Procedures on MODIS LST, GPS TEC, and GIM TEC

Possible Atmosphere and Ionospheric Anomalies of the 2019 Pakistan Earthquake Using Statistical and Machine Learning Procedures on MODIS LST, GPS TEC, and GIM TEC

Detecting Total Electron Content Precursors Before Earthquakes by Examining Total Electron Content Images Based on Butterworth Filter in Convolutional Neural Networks

Possible Seismo Ionospheric Anomalies before the 2016 Mw 7.6 Chile Earthquake from GPS TEC, GIM TEC and Swarm Satellites

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