On Es-spread effects in the ionosphere connected to earthquakes

Liperovskaya, E. V.; Meister, C.‐V.; Pokhotelov, O. A.; Parrot, M.; Богданов, В. В.; Vasil'Eva, N. E.

doi:10.5194/nhess-6-741-2006

Cited by 19 publications

(17 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The influence of seismic events on the lower ionospheric layers, i.e., the upper wall of the waveguide along which VLF signals are propagated, was confirmed by results of measurement of ionospheric parameters. In particular, the results reported by other authors (Liperovskaya et al, 2003;Liperovsky et al, 2005) showed that 3 days before the earthquake the turbulence level in the sporadic E s layer of the ionosphere ARTICLE IN PRESS Fig. 6.…”

Section: Discussionmentioning

confidence: 82%

Variations in thunderstorm VLF emissions propagating over epicenters of earthquakes

Mullayarov

Karimov

Kozlov

2007

Journal of Atmospheric and Solar-Terrestrial Physics

View full text Add to dashboard Cite

Section: Discussionmentioning

confidence: 82%

Variations in thunderstorm VLF emissions propagating over epicenters of earthquakes

Mullayarov

Karimov

Kozlov

2007

Journal of Atmospheric and Solar-Terrestrial Physics

View full text Add to dashboard Cite

“…How ever, such pre cur sors are not eas ily re corded and are sub ject to in tru sion by ra dio waves. In more re cent years, there has been a fo cus on the de tec tion of ion o spheric anom a lies in pre cur sor re search (Liu et al 2001Pulinets 2004;Hegai et al 2006;Heki et al 2006;Liperovskaya et al 2006;Hayakawa 2007). This body of re search has con firmed some ion o spheric anom a lies having re la tion ships with earth quakes, but such re la tion ships have not been suit ably math e mat i cally de scribed; they have re lied on ob ser va tional anal y ses, which can be sub jec tive.…”

mentioning

confidence: 99%

Ionospheric Total Electron Content (TEC) Anomalies Associated with Earthquakes through Karhunen-Loéve Transform (KLT)

Lin¹

2010

Terr. Atmos. Ocean. Sci.

View full text Add to dashboard Cite

AB STRACTThis re search uses eigenvalue char ac ter is tics of the Karhunen-Loéve Trans form of ion o spheric to tal elec tron con tent (TEC) to in ves ti gate pre cur sors for 12 earth quakes of Rich ter mag ni tude scale M ³ 5.0 in a lo cal re gion of lat i tude 23.00 to 24.00°N and lon gi tude 120.00 to 121.50°E for 1 January 2002 to 31 December 2003. Pre vi ous re search ers have found that in the 5 days be fore these earth quakes (i.e., prior to M ³ 5.0), pre cur sors of clear ion o spheric anom a lies show ing sparser to tal elec tron con tent (TEC) were de tected through sta tis ti cal in ves ti ga tion. This was ev i denced through two is sues from Liu and his part ners in 2001 and 2006. These is sues gave cred i ble ev i dence of such pre cur sors. The pre cur sor days hav ing clear ex treme eigenvalues of the Karhunen-Loéve Trans form as the pre cur sors in stead of the sparser ion o spheric TEC were also mostly in the 5 days be fore the 12 earth quakes of greater than M ³ 5.0. The pre cur sors of Chi-Chi Earth quake (M w = 7.6) with clear ex treme eigenvalues were de tected on the 1 st , 3 rd , and 4 th days be fore this earth quake. These re sults are con sis tent with the anal y ses of Liu and his part ner's is sue in 2001. These find ings ver ify the va lid ity of the Karhunen-Loéve Trans form. To fur ther ver ify this ap proach, the Karhunen-Loéve Trans form is ap plied to an earth quake in Ja pan. Pre cur sors to the Ja pan Iwate-Miyagi Nairiku earth quake (M j = 7.2), with clear ex treme eigenvalues are de tected on the 1 st , 2 nd , and 5 th days be fore the earth quake, re spec tively. How ever, af ter de tailed anal y sis, pre cur sors of earth quakes of Rich ter mag ni tude scale M < 5 are not easy to identify using extreme eigenvalues because of existence of other ionospheric features not caused by earthquakes.Key words: Pre cur sors, Karhunen-Loéve trans form, Ion o spheric to tal elec tron con tent (TEC), Tai wan Chi-Chi earth quake, Ja pan Iwate-Miyagi Nairiku earth quake Ci ta tion: Lin, J. W., 2010: Ion o spheric to tal elec tron con tent (TEC) anom a lies as so ci ated with earth quakes through Karhunen-Loéve Trans form (KLT).Terr. Atmos. Ocean. Sci., 21, 253-265, doi: 10.3319/TAO.2009.06.11.01(T) IN TRO DUC TIONTyp i cal tra di tional anal y ses of pre cur sors to earth quakes look at a va ri ety of phe nom ena such as en ergy re lease with elec tric and mag netic field dis tur bances and hot spring analyses (Kuo et al. 2006). How ever, such pre cur sors are not eas ily re corded and are sub ject to in tru sion by ra dio waves. In more re cent years, there has been a fo cus on the de tec tion of ion o spheric anom a lies in pre cur sor re search (Liu et al. 2001Pulinets 2004;Hegai et al. 2006;Heki et al. 2006;Liperovskaya et al. 2006;Hayakawa 2007). This body of re search has con firmed some ion o spheric anom a lies having re la tion ships with earth quakes, but such re la tion ships have not been suit ably math e mat i cally de scribed; they have re lied on ob ser va tional ana...

show abstract

“…This area of study is aimed at using such anomalies to establish earthquake prediction models (Hayakawa 2007;Heki et al 2006;Liperovskaya et al 2006;Liu et al 1996Liu et al , 2001Liu et al , 2006Hegai et al 2006). showed that by using the daily cross-correlation coefficient for ionospheric TEC between two ionosondes (one covering the epicenter of the earthquake and the other hundreds of kilometers Date away) it was possible to identify statistically TEC anomalies occurring up to 7 days before mainshock nucleation.…”

Section: Introductionmentioning

confidence: 99%

Principal component analysis method in the detection of total electron content anomalies in the 24 hrs prior to large earthquakes

Lin

2010

Arab J Geosci

View full text Add to dashboard Cite

The goal of this research is to examine onedimensional total electron content (TEC) data using principal component analysis (PCA) to search for total electron content (TEC) anomalies associated with large earthquakes in 24 h prior to nucleation. The characteristics of principal eigenvalues generated for TEC prior to 24 earthquakes of magnitude scale M≥5.0 and 6 lesser earthquakes of magnitude scale M<5 that occurred in Taiwan from 01 January 2000 to 31 December 2001 are examined. In an earlier paper, I was able to confirm the statistical findings of Liu et al. (J Geophys Res 111, 2006) that sparse earthquake-associated TEC anomalies existed in 5 days prior to the 12 large earthquakes they examined (Lin, Terr Atm Ocean Sci, 2010). In this paper, I wish to examine the subtlety of principal component analysis in detecting earthquake-associated TEC anomalies by examining if such precursors can be detected in 24 h prior to large earthquakes. Of the earthquakes examined, TEC anomalies given by clear extreme principal eigenvalues were evident within 24 h of nucleation for 21 of the 24 earthquakes of M≥5.0. After making allowance for the general status of background TEC, it is clear that these extreme principal eigenvalues are representative of earthquake-associated anomalies. For the smaller earthquakes (M < 5), it was not possible to differentiate earthquake-associated anomalies from background effects on TEC status. These new findings confirm the validity of PCA in searching for earthquake-associated TEC anomalies and show that it is subtle enough to detect TEC anomalies within 24 h leading to a large earthquake. If this approach continues to prove successful, it could theoretically be used in real-time prediction of large earthquakes through early detection of earthquake-associated TEC anomalies.

show abstract

On Es-spread effects in the ionosphere connected to earthquakes

Cited by 19 publications

References 8 publications

Variations in thunderstorm VLF emissions propagating over epicenters of earthquakes

Variations in thunderstorm VLF emissions propagating over epicenters of earthquakes

Ionospheric Total Electron Content (TEC) Anomalies Associated with Earthquakes through Karhunen-Loéve Transform (KLT)

Principal component analysis method in the detection of total electron content anomalies in the 24 hrs prior to large earthquakes

Contact Info

Product

Resources

About