Eigenstate Transition of Multi-Channel Time Series Data around Earthquakes

Round 1

Reviewer 1 Report

Reviewer’s Report on the manuscript entitled:

Eigenstate Transition of Multi-channel Time-series Data around Earthquakes

The authors developed a covariance matrix from multichannel time series data observed by an observatory on the seafloor and calculate the first eigenvalue and corresponding eigenstate of the matrix that may be useful to help detecting earthquakes before their occurrences. Although the topic is interesting, the manuscript needs improvement, particularly the English grammar, and discussion and conclusion parts. Below please see my comments.

Time series is often used without a hyphen, thus please remove the hyphen throughout the manuscripts.

There are many grammar issues in the paper:

Line 1 in Abstract. This is a vague sentence. Please rewrite a more rigorous sentence.

Line 3. It should be “precedes”.

Line 9. It should be “in which eigenvalue increases”.

Line 11. It should be “are useful”.

Line 181. It should be “eigenvalue increases”.

Line 65. Please in a few sentences describe how the rest of the paper is organized.

Line 69. It should be “website”

Lines 67-88. It should be in Section “2.1. Data sets and pre-processing”

Lines 88-152. It should be in Section “2.2. Methodology”

Table 1 and Line 132. The unit Richter should be inserted for magnitude.

Line 126. When you refer to Figures, please always use the following format: Figure x. So, it should be Figure 2.

Figure 3. Since the x-axis values are all the same, I suggest the authors to join the x-axes for the left three panels and the right three panels. This way, the authors can also enlarge the size of the panels for better visualization.

The Discussion part is short and insufficient. Please here discuss other robust techniques of multichannel time series analysis techniques for seismic data analysis, such as

Multichannel Anti-Leakage Least-Squares Spectral Analysis (MALLSSA) that uses a windowing strategy and spectral analysis for seismic noise attenuation and rigorous analysis of vibration with the aid of covariance matrices and additional data:

https://doi.org/10.1007/s11600-019-00320-3

Detecting earthquake-related anomalies based on Multichannel Singular Spectrum Analysis (MSSA):

https://doi.org/10.3390/e22101086

Multi-Resolution Wavelet Analysis (MRWA) for investigating possible complex correlations in the evolution of seismicity:

https://doi.org/10.3390/geosciences11090379

I suggest the authors to add a paragraph toward the end of the discussion section and briefly describe the methods mentioned above and their possible application in the future direction of this research.

Line 236. The conclusion part is short. Please also add the limitation of this study, challenges, and future direction.

Please add an acronym table at the end of the manuscript listing all the abbreviations used.

Please carefully check the references to ensure they are correct and have a consistent format according to the MDPI guidelines.

Thank you for your contribution

Regards,

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Very good work

Comments for author File: Comments.pdf

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

I would like to thank the authors for addressing all of my comments. The manuscript is significantly improved, and I recommend acceptance.

Thank you for your contribution

Regards,