Fault distance-based approach in thermal anomaly detection before strong Earthquakes

Karimi Zarchi, Arash; Saradjian Maralan, Mohammad Reza

doi:10.22059/eoge.2023.355601.1132

Fault distance-based approach in thermal anomaly detection before strong Earthquakes

Document Type : Original Article

Authors

¹ Remote Sensing Department, School of Surveying and Geospatial Engineering, Collage of Engineering, University of Tehran, Tehran, Iran

² School of Surveying and Geospatial Engineering, College of Engineering, University of Tehran

10.22059/eoge.2023.355601.1132

Abstract

The recent scientific studies in the context of earthquake precursors reveal some processes connected to seismic activity including thermal anomaly before earthquakes which is a great help for making a better decision making regarding this disastrous phenomenon and reducing its casualty to a minimum. This paper presents a method for grouping the objective input data for different thermal anomaly detection methods using the land surface temperature (LST) mean in multiple distances from the corresponding fault during the 40 days (30 days before and 10 days after the impending earthquake) of investigation. Six strong earthquakes with Ms > 6 that have occurred in Iran have been investigated in this study. We used two different approaches for detecting thermal anomalies: the mean-standard deviation method and the interquartile method. Results show that the proposed input data produces fewer false alarms in each of the thermal anomaly detection methods compared to the ordinary input data making this method much more accurate and stable regarding the easy accessibility of thermal data and their less complicated algorithms for processing. In the final step, the detected anomalies are used for estimating earthquake intensity using Artificial Neural Network (ANN). The results show that the estimated intensities of most earthquakes are very close to the actual intensities. Since the locations of the active faults are known a priori, using fault distance-based approach may be regarded as a superior method in predicting the impending earthquakes for vulnerable faults. In spite of the previous investigations that the studies were only possible aftermath, the fault distance-based approach can be used as a tool for future unknown earthquakes prediction. However, it is recommended to use thermal anomaly detection as an initial process to be jointly used with other precursors to reduce the number of investigations that require more complicated algorithms and data processing.

Keywords