Is There An EarthquakeMigration Global Pattern?S13A-2516

Results

Abstract

Introduction

Earthquake migration patterns before large earthquake were proposed by Mogi, (1968). The existence of the cor-relation between earthquakes over distances that show probable global interdependence is a theme that is cer-tainly one of the most intriguing in field of seismology. In this job, we will present the phenomenology of earth-quake migration global seismic pattern empirically, in or-der to ensure statistically the correlation of long range and lead to confrontation these seismic patterns. We used the USGS catalog. We found that the pair of events that have a good correlation are confirmed statistically.As Shebalin (1996) shown the earthquake chain, we show that first stage of the earthquake prediction correlation for large distances.

Earthquake migration patterns before large earthquake were proposed by Mogi (1968) and the existence of the cor-relation between earthquakes over distances show proba-ble global interdependence (Romanowicz 1993, Shebalin 2006). Others studies of spatio-temporal changes in seis-micity prior to large earthquakes (Gutenberg and Rich-ter, 1954; Keilis-Borok and Malinovskaya, 1964; Prozorov and Schreider, 1990; Shaw et al., 1997; Jaume and Sykes, 1999; Keilis-Borok, 2003, Wu et al., 2008) also show the evidences of long-range correlation to large earthquakes. This theme is certainly one of the most intriguing in field of seismology, and might explain this probable correla-tion and identify the patterns earlier proposed.

The study of earthquakes forecasting/prediction seemed to be a path without solution, bringing several attempts to find consistent predictions, such as the precursors of major events, which seemed to be just a regional solution with-out demonstrating a global effect correlation. Recently, a new methodology has been identified in earthquake forecast, crediting a new step for seismology. Thus, this work aims to a new understanding of the behavior of earthquakes based on empirical observation of seismic catalogues of the leading world seismology centers such as European Mediterra-nean Seismological Centre (EMSC), National Earthquake Information Center – United Stated Geological Survey (NE-IC-USGS), Incorporated Research Institutions for Seismology (IRIS), German Research Centre for Geosciences (GFZ) etc. The seismic migration model proposed is still under development. The monitoring results found on the websites of USGS, were fundamental to the research. Doing the opposite direction to the current research models, using the prac-tice as a means of empirical evidence, along with the media, we forced a deeper inquiry regarding our problem: Is There An Earthquake Migration Global Pattern?

Manually collected data is used as the basis for automation and consolidation of probable seismic migration using the Flinn-Engdahl region as accurately as possible. It was observed that the pairs of consequent events over magnitude are well correlated. Only migration 4, manually collected, showed inconsistency with the value obtained automatically, how-ever it was still possible to observe a probable migration pattern. The data collection showed that the migration path 1 has forward and reverse, with automated values greater than the average collected manually, one for the direct path with an average travel time of 2.5 days and 2.3 for the reverse path. The other migrations demonstrated values below 0.6 days (~ 14 hours), it can be directly correlated with the distance of migration. Migration 2 was separated, as they are in dif-ferent regions Flinn-Engdahl, however did not show big difference. Migration 3 remained with the manual collection and migration 4, was separated according to depth, with a low number of observations, but we can infer that the travel time is greater for those depths. Graphs were made Ncum (cumulative number of earthquake the day versus days), em-phasizing the probability of migration patterns. The next step is to test the correlation between various parameters to ensure the migration of real events and set more migration paths.

We would like to thank the staff of Quake Red Alert, di-rectly responsible for the elaboration and implementation of this article. We would also like to thank the teachers Ana Cecilia Dos Santos and Alexandre J. Schumacher for their assistance provided. We realize that the non-integra-tion of the seismic observatories databases made this job more difficult, a situation that can be easily resolved by adopting a single standard for the measurements, as well as a unification of the database.

Flinn, E.A., Engdahl, E.R. and Hill, A.R., 1974, Seismic and geographical regionalization, Bulletin of the Seismological Society of America, vol. 64, p. 771-993.

Gutenberg, B., Richter, C.F., 1954. Seismicity of the Earth and Associated Phenomena. Haf-ner, New York.

Jaume, S.C., Sykes, L.R., 1999. Evolving toward a critical point: a review of accelerating seismic moment/energy release prior to large and great earthquakes. Pure Appl. Geophys. 155, 279–306.

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Mogi, K., 1968, Source locations of elastic shocks in the fracturing process in rocks, Bull. Earthquake Res. Inst. Univ. Tokyo, 46, 1103– 1125.

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Identifying the EarthquakeMigration Global Pattern

Parameters and Correlations

Conclusion

References

Acknowledgments

www.quakeredalert.com

We used the data from the catalogs covering a time peri-od from 1998 to 2011 and selected four seismic patterns that had almost constants and similar magnitudes. Each Seismic pattern was named according to a Flinn-Engdahl Region (Flinn et al., 1974). For this work we present the migrations (Figure 1) of Vanuatu-North Japan, Fiji-Peru, Bolivia-Xizang and Santiago-Tonga.

To define the precision of the selected seismic patterns we defined mathematical models to establish a linear correla-tion for seismic events pairs based on observations of time (T1 e T2), epicenter [P1(l1,j1) and P2(l2,j1)], depth(h1 and h2) and magnitude (M1 and M2). Thus, were defined as parameters to be determined the variations between distance of epicenter, magnitude, and travel time between the events (ΔT, ΔM and ΔD). T2 = T1 + ΔT (01) P2 = P1 + ΔD (02) M2 = M1 + ΔM (03)Assuming that the parameters are independent of each other, we used the mean and standard deviation as sta-tistical information for the pair events, and as criteria for selecting event pairs automatically we used the standard deviation as the threshold of the selected data.

There were two processes, the first by visual observation (manual) where pairs of events from the catalogue (from 2004-2011) were selected, and the second was through the same catalogue, but with automatically selected pairs of events, considering only the first subsequent event (1998 to 2011), and then determining the parameters (Table 1). In this work we separated four migration patterns:Migration 1 - Xizang to Bolivia [Flinn and Engdahl regions - Xizang, 305 (Western Xizang-India Border Region) and 306 (Xizang), Bolivia, 124 (Chile-Bolivia border region) and 125 (Southern Bolivia)].Migration 2 - Fiji to Peru [Flinn and Engdahl regions - Fiji, 171 – South of Fiji Islands and 181 - Fiji Islands Region, Peru, 108 - Off Coast Of Northern Peru, 109 - Near Coast Of Northern Peru, 110 - Peru-Ecuador Border Region, 111 Northern Peru, 112 Peru-Brazil Border Region, 113 Western Brazil, 114 Off Coast Of Peru, 115 Near Coast Of Peru, 116 Central Peru, and 117 Southern Peru].Migration 3 - Vanuatu to Japan [Flinn and Engdahl re-gions - Vanuatu, 185 Vanuatu Islands Region and 186 Vanuatu Islands, Japan, 226 Near West Coast Of Hons-hu, 227 Eastern Honshu, 228 Near East Coast Of Hons-hu, 229 Off East Coast Of Honshu and 230 Near S. Coast Of Honshu].

Migration 4 - Santiago Del Estero to Tonga [Flinn and Engdahl regions - Santiago Del Estero, 132 - Santiago Del Estero Prov., Arg., Tonga,171 - South Of Fiji Islands, 173 Tonga Islands and 174 Tonga Islands Region].

Objective

Earthquake MigrationGlobal Pattern

We intended to prove the hypothesis that earthquakes and seismic migration may be related to different points in long distances around the world MOGI (1968). From this point the seismic migration patterns could be identified, allowing it’s identification before the major earthquakes occur. One can also identify the existence of correlation between these earthquakes over distances, showing prob-able global interdependence.

We consider the earthquake migration patterns, pairs of events with similar magnitudes and time variation, con-sidering only the main events without using the presence of aftershocks. After selecting the patterns, we established linear correlations between migration events based on ob-servation of time, epicenter, depth and magnitude.

UnBAroldo M. M. dos sAntos², GeorGe s. FrAnçA¹, André G. dA silveirA², GreGorio v. FriGeri², GiuliAno s. MArottA¹

¹ Grupo de Pesquisar Sismicidade Induzida e Natural/CNPq Observatório Sismológico - Universidade de Brasília² Universidade de Cuiabá

n SeismicPattern

Obs. Visual

Obs.Aut.

Travel timeVisual (days)

Travel timeAut. (days) Distances

Visual (º)DistancesVisual (º)

Differenceof magnitudes

Visual

Differenceof magnitudes

Aut.

1 Xizang Bolívia 15 171 1.07±0.16 2.53±2.18 162.32±1.49 155.69±4.09 0.03±0.15 -0.02±0.30

Bolívia Xizang 7 157 0.68±0.15 2.31±2.05 160.65±1.03 155.57±4.03 0.03±0.13 0.02±0.31

2 Fiji - Peru 44 0.28±0.07 103.26±0.81 0.08±0.06Fiji171to Peru 255 0.41±0.33 98.08±1.41 0.02±0.30

Fiji 181to Peru 411 0.32±0.27 98.66±1.31 0.05±0.30

3 Vanuatu Japan 49 625 0.20±0.05 0.48±0.47 59.24±1.29 59.06±1.67 -0.20±0.06 -0.18±0.30

4 SantiagoTonga 5 24 20.64±9.61 0.42±0.47 112.69±4.47 99.32±1.67 -0.50±0.430 -0.13±0.40

8 0.61±0.48 98.65±1.44 -0.16±0.18

aroldomaciel@gmail.com georgesand@unb.br agsgalvan@gmail.com gregoriofrigeri@gmail.com marotta@unb.br