Rapid Estimation of Earthquake Magnitude and Source Parameters Using Genetic Algorithms

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.

Prediction of Tsunami Alert Levels Using Deep Learning

“…Traditional methods based on seismometer data are inaccurate in such short period of time, and they tend to underestimate the value of the magnitude in large earthquakes (Novianty et al, 2021). Blewitt et al (2006) demonstrated that the earthquake magnitude can be determined using high-resolution GPS data within the first 15 min after the start of the earthquake, by tracking the mean displacement of the Earth's surface associated with the arrival of seismic waves.…”

“…In order to apply scaling laws when an earthquake has been detected, previously its magnitude M w should be determined as fast an accurately as possible, ideally within a few minutes after the occurrence of the earthquake. Traditional methods based on seismometer data are inaccurate in such short period of time, and they tend to underestimate the value of the magnitude in large earthquakes (Novianty et al., 2021).…”