Observations of infragravity period oscillations in a small marina

The authors measured water levels in Two Rocks Marina, Western Australia, to investigate infragravity-period (25–300 s) oscillations and their forcing mechanisms. Spectral analyses identified four dominant oscillations in the infragravity band, which were generated through excitation of the marina’s natural periods. The oscillations were present at all times, independent of the offshore conditions, indicating that they were forced by a continuous external energy source. The spectral energy of the oscillations increased by ~50 times during storm events (higher incident wave heights), in comparison to calm events (lower incident wave heights). Wave heights of oscillations within the marina were strongly correlated with offshore incident swell wave heights and reached maximum of 0.5 m. The groupiness factor of swell waves around the marina was 0.6–0.85. Bound infragravity waves associated with swell wave groups were identified as potential forcing mechanism of infragravity-period oscillations within the marina. The bound infragravity waves have broad frequency spectrum without dominant periods matched the marina’s natural periods however, bound infragravity waves of periods in the proximity of the marina NOPs were adequate to generate oscillations at the NOPs of the marina. Frequencies of the oscillations were independent of the forcing frequency, and determined by the marina's geometry.

• Record URL:
  • https://doi.org/10.1016/j.oceaneng.2014.07.003
• Record URL:
  • http://www.sciencedirect.com/science/article/pii/S0029801814002662
• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/00298018
• Supplemental Notes:
  • Abstract reprinted with permission of Elsevier.
• Authors:
  • Thotagamuwage, Darshani T
  • Pattiaratchi, Charitha B
• Publication Date: 2014-9-15

Language

• English

Media Info

• Media Type: Digital/other
• Features: Figures; Maps; References; Tables;
• Pagination: pp 435-445
• Serial:
  • Ocean Engineering
  • Volume: 88
  • Issue Number: 0
  • Publisher: Pergamon
  • ISSN: 0029-8018
  • EISSN: 1873-5258
  • Serial URL: http://www.sciencedirect.com/science/journal/00298018

Subject/Index Terms

• TRT Terms: Docking; Gravity waves; Harbors; Marinas; Oscillation; Properties of water waves; Wind waves
• Geographic Terms: Western Australia
• Subject Areas: Hydraulics and Hydrology; Marine Transportation; Terminals and Facilities; I21: Planning of Transport Infrastructure;

Filing Info

• Accession Number: 01534868
• Record Type: Publication
• Files: TRIS
• Created Date: Aug 20 2014 3:36PM