Continuous Monitoring of Fluid and Gas Geochemistry for Seismic Study in Taiwan

Fu, Ching‐Chou; Lee, L. C.

doi:10.1002/9781119156949.ch11

Cited by 9 publications

(16 citation statements)

References 53 publications

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“…Seismological studies have been conducted in Taiwan for more than one century (Wang 1998). Different types of seismic, geodetic, geophysical, and geochemical stations have been constructed in the region (Yeh et al 1981;Wang 1989;Shin and Chang 2005;Fu and Lee 2018;Chen and Chen 2016). Figure 1 also displays the stations that are used in this study and described below.…”

Section: Introductionmentioning

confidence: 99%

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A compilation of precursor times of earthquakes in Taiwan

Wang

2021

Terr. Atmos. Ocean. Sci.

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The precursor time, T, is the time interval between the occurrence time of a precursor and that of a forthcoming earthquake with local magnitude, M L . The precursors are classified into four types of earthquake prediction with different time windows: long-term prediction (T = 3 to 10 years); intermediate-term prediction (T = 6 months to 3 years); short-term prediction (T = 8 days to 6 months); and imminent prediction (T ≤ 7 days). Since the 1999 Chi-Chi earthquake, the precursors for numerous earthquakes in Taiwan have been observed and studied. The values of T and M L are compiled from scientific literature. The plots of T versus M L are made for some precursors when the data sets are large with the values of T for respective events. Such precursors are the b-value anomalies, foreshocks, thermal infrared radiation anomalies, geochemical composition changes, radon changes, γ-ray emission anomalies, and total electron content (TEC) anomalies. There is a positive correlation between T versus M L for the b-value anomalies, foreshocks, Rn changes, and γ-ray emissions. The relationship of log(T) versus M L is also inferred for Rn changes. The precursor time for Rn changes is positively correlated with that for γ-ray emissions. The time difference between the precursor time for Rn changes and that for γ-ray emissions is positively correlated to M L . However, the plots for thermal infrared radiation, geochemical composition changes, and TEC anomalies are quite scattered and thus not any correlation can be obtained. The positive correlations between T and M L or some precursors suggest the possibility of earthquake prediction in future.

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Section: Introductionmentioning

confidence: 99%

“…Chen et al (2013b) reviewed the groundwater level changes for M L ≥ 6 earthquakes. Fu and Lee (2018) reviewed geochemical precursors.…”

Section: Introductionmentioning

confidence: 99%

A compilation of precursor times of earthquakes in Taiwan

Wang

2021

Terr. Atmos. Ocean. Sci.

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“…Simultaneously related anomalous radon patterns, which lasted for a longer period of time at all the South monitoring stations, especially at PT and CL-T1, along with the Southeastern monitoring station are interpreted to be representative as precursory signals to the Meinong earthquake. Similarly, Fu and Lee (2017) has reported significant changes in soil radon simultaneously at four stations in southern Taiwan approximately two weeks before the 2010 Jiasian earthquake. Furthermore, the significant rate-slow-down anomalies in cGPS pre-seismic baseline variations near the epicenter of the Meinong earthquake were also demonstrated in southern Taiwan (Tsai et al 2017).…”

Section: Resultsmentioning

confidence: 99%

Preseismic anomalies in soil-gas radon associated with 2016 M 6.6 Meinong earthquake, Southern Taiwan

Fu¹,

Walia²,

Yang³

et al. 2017

Terr. Atmos. Ocean. Sci.

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Taiwan is tectonically situated in a terrain resulting from the oblique collision between the Philippine Sea plate and the continental margin of the Asiatic plate, with a continuous stress causing the density of strong-moderate earthquakes and regional active faults. The continuous time series of soil radon for earthquake studies have been recorded and some significant variations associated with strong earthquakes have been observed. Earthquake prediction is not still operative but these correlations should be added to the literature about seismo-geochemical transients associated to strong earthquakes. Rain-pore pressure related variations, crustal weakness at the studied faults system is consistent with the simultaneous radon anomalies observed. During the observations, a significant increase of soil radon concentrations was observed at Chunglun-T1 (CL-T1), Hsinhua (HH), Pingtung (PT), and Chihshan (CS) stations approximately two weeks before the Meinong earthquake (M L = 6.6, 6 February 2016) in Southern Taiwan. The precursory changes in a multi-stations array may reflect the preparation stage of a large earthquake. Precursory signals are observed simultaneously and it can apply certain algorithms the approximate location and magnitude of the impending earthquake.

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“…The 2010/03/04 M6.4 Jiashian Earthquake (EQ-7) occurred in southern Taiwan. Significant changes in soil radon concentrations along the fault zones over the epicenter were observed ∼14 days before EQ-7, followed by the appearance of the POEA from satellite data and the crust with surface movement based on GPS residual displacement nearly 10 days before the event (Chen et al, 2013c;Fu and Lee, 2018). Similarly, the reoccurrence of a significant increase in soil radon concentrations was found ∼2 weeks before the 2020/02/06 M6.6 Meinong earthquake (EQ-26) in southern Taiwan, and a substantial POEA occurred following the radon anomalies 9-12 days before the EQ-26 event (Fu et al, 2017a).…”

Section: Relationship Between Olr E Index Variations and Seismicitymentioning

confidence: 99%

“…Identifying earthquake precursors has often been considered a useful method to mitigate seismic disasters. In the past few decades, a wide variety of earthquake precursors have been investigated for Taiwan, including gas and fluid geochemical changes (Liu et al, 1985;Song et al, 2003Song et al, , 2006Chyi et al, 2005;Fu et al, 2005Fu et al, , 2008Fu et al, , 2009Fu et al, , 2017aYang et al, 2005Yang et al, , 2006Kuo et al, 2006Kuo et al, , 2010Walia et al, 2009Walia et al, , 2013Kumar et al, 2015;Fu and Lee, 2018), gamma-ray monitoring (Fu et al, 2015(Fu et al, , 2019, groundwater levels (Chia et al, 2001;Wang et al, 2001;Lai et al, 2010;Chen et al, 2013bChen et al, , 2015c, borehole strain changes (Liu et al, 2009;Canitano et al, 2015Canitano et al, , 2017Hsu et al, 2015), seismicity changes (Chen et al, 2005(Chen et al, , 2006Wu and Chiao, 2006;Wu and Chen, 2007;Wu et al, 2008;Lin, 2009;Kawamura et al, 2014), tidal variations (Lin et al, 2003;Chen et al, 2012), GPS observations (Chen et al, 2013c(Chen et al, , 2015b, lightning activity (Liu et al, 2015),...…”

Section: Introductionmentioning

confidence: 99%

Earth’s Outgoing Longwave Radiation Variability Prior to M ≥6.0 Earthquakes in the Taiwan Area During 2009–2019

Lee

Ouzounov

et al. 2020

Front. Earth Sci.

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This paper proposes an analysis method, using the National Oceanic and Atmospheric Administration satellite data, to trace variations in outgoing longwave radiation (OLR) for finding the precursors of earthquakes. The significance of these observations is investigated using data sets of recent M ≥6.0 earthquakes around the Taiwan area from 2009 to 2019. We suggest that the precursory signal could be an E Index anomaly (EA) in the form of substantial thermal releases distributed near the epicenter. The consecutive appearances of OLR EAs are observed as precursors 2-15 days before significant earthquakes, and we refer to this as a pre-earthquake OLR E Index anomaly (POEA). We interpret these thermal sources as possibly originating from electromagnetics together with gas emissions associated with pre-seismic processes. This study highlights the potential of OLR anomalous changes in earthquake precursor studies, at least in the Taiwan region.

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Continuous Monitoring of Fluid and Gas Geochemistry for Seismic Study in Taiwan

Cited by 9 publications

References 53 publications

A compilation of precursor times of earthquakes in Taiwan

A compilation of precursor times of earthquakes in Taiwan

Preseismic anomalies in soil-gas radon associated with 2016 M 6.6 Meinong earthquake, Southern Taiwan

Earth’s Outgoing Longwave Radiation Variability Prior to M ≥6.0 Earthquakes in the Taiwan Area During 2009–2019

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