2024
Ref: POSTER-2025-0029

From oceanic waves to seismic wiggles, then and now

De Plaen, Raphael ; Lecocq, Thomas ; Colin, Fabienne


Poster presented at Geologica Belgica Luxemburga International Meeting 2024, Liège, Belgium on 2024-09-12

Abstract: Since the early days of instrumental seismology, seismometers have been recording various continuous natural and human-generated sources. The oceanic microseisms caused by the atmosphere-ocean-solid Earth coupling mechanisms are the main natural source of seismic ambient noise. Because these microseisms are directly related to the oceanic climate, the legacy seismograms, recorded on analog instruments, are a unique repository of quantitative observations of past storm events, most of which occurred before modern global satellite observation became available. However, the analog nature of these records has limited their accessibility and utility in contemporary research. These challenges are now addressed using advanced image processing and machine learning techniques to digitize and vectorize these historical seismograms. This process involves scanning the analog records, extracting seismic waveforms, and transforming them into calibrated, time-coded digital time series. A critical step also involves compiling detailed metadata about historical seismic instruments to construct accurate instrument response functions, ensuring that the digitized data meets modern scientific standards. The vectorized seismic data are validated through a first-order comparison between the extracted microseismic signals and the theoretical microseismic ground motions derived from the WaveWatch III oceanic models. This validation process helps confirm the reliability of the digitized data by focusing on the significant storms that impacted the Atlantic North East. Once implemented in large numbers of seismic observatories, this will help improve existing ocean models by integrating quantitative observations currently lacking for most of the 20th century. This potential to help improve climate reanalysis for the pre-satellite era motivates the digitization and vectorization of old seismic data. Nevertheless, bringing these legacy seismic data to the digital age will, in turn, also help implement modern seismic analysis on these datasets, bringing a fresh look at old natural and human-made sources ranging from earthquakes to nuclear explosions.

Keyword(s): Microseism ; Oceanic storms ; Legacy seismic data ; Seismic ambinet noise
Funding: BRAIN-be 2.0 SeismoStorm/BRAIN-be 2.0 SeismoStorm/BRAIN-be 2.0 SeismoStorm


The record appears in these collections:
Royal Observatory of Belgium > Seismology & Gravimetry
Conference Contributions & Seminars > Posters



 Record created 2025-01-21, last modified 2025-01-21


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