Preprints
https://doi.org/10.5194/egusphere-2024-1614
https://doi.org/10.5194/egusphere-2024-1614
05 Jun 2024
 | 05 Jun 2024
Status: this preprint is open for discussion.

Contemporary measurements of the background open ocean tsunami spectrum using the Deep-ocean Assessment and Reporting of Tsunami (DART) stations

Sean R. Santellanes and Diego Melgar

Abstract. A reference power law of ω2, where ω is angular frequency, has been traditionally used to characterize the background open ocean tsunami spectrum (BOOTS) slope from a period of 10 mins to 120 mins. However, this characterization is based on data from temporary deployments of bottom pressure sensors that lasted from several weeks to 11 months and only in scattered areas of the Pacific, leaving its effects on aleatory and epistemic uncertainties of tsunami source models unconstrained. Here we measure the BOOTS slope using 1–15 years of bottom pressure recorder data sampled at 15 s from the Deep-ocean Assessment and Reporting of Tsunamis (DART) stations. We utilize probabilistic power spectral density plots to create background noise models for 34 DART stations across the Pacific basin. We find that often a simple log-linear decay does not correctly characterize the observed background spectrum. We find deviations from the expected –2 behavior with instances of it being larger or greater, with a strong seasonality signal. In addition, we plot the median power for each DART station at the periods of 120 s, 250 s, and 800 s. Lastly, a significant part of the energy in the BOOTS is from infragravity waves, we calculate their heights and their mean values for December, January, and February and June, July, and August. We found that meteorologically induced infragravity wave events are the largest factors in seasonal variations of the BOOTS slope and intercept, especially in the east Pacific. We show the typical meteorological systems that drive these events, and we connected tropical systems from off the coast of Mexico to infragravity wave events in the east and central Pacific. Finally, we found that infragravity wave events may impact small to moderate tsunamis. 

Publisher's note: Copernicus Publications remains neutral with regard to jurisdictional claims made in the text, published maps, institutional affiliations, or any other geographical representation in this preprint. The responsibility to include appropriate place names lies with the authors.
Sean R. Santellanes and Diego Melgar

Status: open (until 17 Jul 2024)

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse
Sean R. Santellanes and Diego Melgar
Sean R. Santellanes and Diego Melgar

Viewed

Total article views: 80 (including HTML, PDF, and XML)
HTML PDF XML Total BibTeX EndNote
56 17 7 80 3 2
  • HTML: 56
  • PDF: 17
  • XML: 7
  • Total: 80
  • BibTeX: 3
  • EndNote: 2
Views and downloads (calculated since 05 Jun 2024)
Cumulative views and downloads (calculated since 05 Jun 2024)

Viewed (geographical distribution)

Total article views: 78 (including HTML, PDF, and XML) Thereof 78 with geography defined and 0 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 
Latest update: 12 Jun 2024
Download
Short summary
Our study measured the Background Open Ocean Tsunami Spectrum (BOOTS) slope using 1–15 years of bottom pressure recorder data from 34 Deep-ocean Assessment and Reporting of Tsunamis (DART) stations to verify if it does follow the reference power law across the Pacific Ocean. We found that the BOOTS varies from the reference power law substantially in the east Pacific due to the affects of various weather systems.