Automatically Plotting Record Section for an Earthquake in the Given Time Range in Python (codes included)

Utpal Kumar 2 minute read GEOPHYSICS July 08, 2020

Introduction

A seismic record section displays numerous seismic records in a single figure and can be quite useful in the geological interpretation. The ray paths of the seismic waves are curved due to increasing velocity with depth. Hence, the longer the distance to the station from the event, the deeper the ray goes.

Key idea — let the script do the picking. A record section stacks many seismograms by epicentral distance so the P and S moveout curves stand out. Building one by hand means choosing an event, listing stations, downloading waveforms, and aligning them. This tool automates that: you fill in one YAML config (input_file.yml) with a time range, a geographic region, and a network; the script finds the largest-magnitude earthquake in that window, pulls the waveforms over FDSN with ObsPy, and renders the record section for you.

The automation in three steps: edit one config file, let the script select the biggest quake and fetch its waveforms, then plot the record section.

Download the complete script:

Code to automatically plot the record section of largest earthquake event within the given time range and geographical selection.
Define the input parameters in input_file.yml

View File input_file.yml

Run the python script plot_record_section.py

View Code for plot_record_section.py

Run Script

Install environment for the required packages using either one of the following commands (spec-file.txt and environment.yml can be downloaded from the github link): conda install --name myenv --file spec-file.txt conda env create -f environment.yml
Execute script python plot_record_section.py

Input file

Record section 1

Runshot 1 Runshot 2

Download the complete script here.

References

Prescott, H. R. (1951). Seismic record sections. Geophysics, 16(4), 613–625.

Quick check: What does this script decide for you that a manual record-section workflow leaves you to do by hand?

It computes the Earth’s velocity model from scratch
It picks the largest-magnitude earthquake in your chosen time range and region, then downloads its waveforms automatically
It removes the instrument response and deconvolves the source
It renders the plot in 3-D instead of 2-D

Recap

A record section stacks seismograms by epicentral distance; this tool builds one automatically for the biggest event in a time/space window.
You configure everything in one input_file.yml (time range, region, network) — no editing of the plotting code needed.
Reproduce the environment from the repo’s environment.yml / spec-file.txt, then run python plot_record_section.py.
Under the hood it uses ObsPy + an FDSN client to query the catalog and fetch waveforms — the same building blocks as the manual tutorials.

Where to go next

Plotting seismograms with increasing epicentral distance — the manual, step-by-step version with the P/S moveout explained.
Getting started with ObsPy — Part I — downloading waveform data with an FDSN client.
automated_seismic_record_section on GitHub — the full source, config, and environment files.

This post was last modified at 2026-07-20 03:00.

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