Earthquake signals are non-stationary in nature and thus in real-time, it is difficult to identify and classify events based on classical approaches like peak ground displacement, peak ground velocity. Even the popular algorithm of STA/LTA requires extensive research to determine basic thresholding parameters so as to trigger an alarm. Also, many times due to human error or other unavoidable natural factors such as thunder strikes or landslides, the algorithm may end up raising a false alarm. This work focuses on detecting earthquakes by converting seismograph recorded data into corresponding audio signals for better perception and then uses popular Speech Recognition techniques of Filter bank coefficients and Mel Frequency Cepstral Coefficients (MFCC) to extract the features. These features were then used to train a Convolutional Neural Network(CNN) and a Long Short Term Memory(LSTM) network. The proposed method can overcome the above-mentioned problems and help in detecting earthquakes automatically from the waveforms without much human intervention. For the 1000Hz audio data set the CNN model showed a testing accuracy of 91.1% for 0.2-second sample window length while the LSTM model showed 93.99% for the same. A total of 610 sounds consisting of 310 earthquake sounds and 300 non-earthquake sounds were used to train the models. While testing, the total time required for generating the alarm was approximately 2 seconds which included individual times for data collection, processing, and prediction taking into consideration the processing and prediction delays. This shows the effectiveness of the proposed method for Earthquake Early Warning (EEW) applications. Since the input of the method is only the waveform, it is suitable for real-time processing, thus the models can also be used as an onsite EEW system requiring a minimum amount of preparation time and workload.
翻译:地震信号在性质上不是静止的,因此在实时情况下,很难根据典型方法,如高峰地面迁移、高峰地面速度等,确定和分类事件。即使STA/LTA的流行算法也需要进行广泛的研究,以确定基本临界参数,以触发警报。此外,由于人为错误或其他不可避免的自然因素,如雷电或山崩等,算法可能最终造成虚假的警报。这项工作的重点是通过将地震记录的数据转换成相应的音频信号,以获得更好的感知,然后利用过滤银行系数和Mel Right Cepstral Covales(MFCC)等流行语音识别技术来提取特征。即使STA/LTA的流行算法也需要进行广泛的研究,以确定基本临界值,以确定基本临界值,然后利用这些功能来训练一个连动神经网络(CNN)和一个长的短期内记忆(LLSTM)网络(LSTM)网络(LSTM)的流行算法,许多时候用于从波形中自动探测地震,而无需人干预。CN的音模型只显示0.2秒的测测测算,因此测算方法是用于地震的测算。