Rapid Estimation of Earthquake Magnitude and Source Parameters Using Genetic Algorithms

Astri Novianty,Sri Widiyantoro,Irwan Meilano,Susilo Susilo,Carmadi Machbub

doi:10.3390/app112411852

Abstract

To minimize the impacts of large losses and optimize the emergency response when a large earthquake occurs, an accurate early warning of an earthquake or tsunami is crucial. One important parameter that can provide an accurate early warning is the earthquake’s magnitude. This study proposes a method for estimating the magnitude, and some of the source parameters, of an earthquake using genetic algorithms (GAs). In this study, GAs were used to perform an inversion of Okada’s model from earthquake displacement data. In the first stage of the experiment, the GA was used to inverse the displacement calculated from the forward calculation in Okada’s model. The best performance of the GA was obtained by tuning the hyperparameters to obtain the most functional configuration. In the second stage, the inversion method was tested on GPS time series data from the 2011 Tohoku Oki earthquake. The earthquake’s displacement was first estimated from GPS time series data using a detection and estimation formula from previous research to calculate the permanent displacement value. The proposed method can estimate an earthquake’s magnitude and four source parameters (i.e., length, width, rake, and slip) close to the real values with reasonable accuracy.

Highlights

Earthquakes with large magnitudes always result in large losses and can even trigger a subsequent disaster such as a tsunami
Two experimental stages were involved in this study, namely, tuning of the genetic algorithms (GAs)
GAs to carry out inversion of Okada’s model to estimate four earthquake source parameters and to obtain the hyperparameter setting that resulted in the best performance of the Okada–GA inversion model

Summary

Introduction

Earthquakes with large magnitudes always result in large losses and can even trigger a subsequent disaster such as a tsunami. To provide an early warning for tsunamis and facilitate emergency responses to earthquakes, one important parameter that needs to be known early and as accurately as possible is the earthquake’s magnitude [1]. If the earthquake’s magnitude is estimated at 6.5 or greater, the system will issue a warning that the earthquake has the potential to trigger a tsunami [3]. In some previous cases of large earthquakes that have triggered tsunamis, the early warning was inaccurate because the magnitude was underestimated at crucial times [4,5,6,7]

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Methods

Results

Discussion

Conclusion