Are meteotsunamis an underrated hazard?

Abstract

Meteotsunamis are generated by meteorological events, particularly moving pressure disturbances due to squalls, thunderstorms, frontal passages and atmospheric gravity waves. Relatively small initial sea-level perturbations, of the order of a few centimetres, can increase significantly through multi-resonant phenomena to create destructive events through the superposition of different factors. The global occurrence of meteotsunamis and the different resonance phenomena leading to amplification of meteotsunamis are reviewed. Results from idealized numerical modelling and field measurements from southwest Australia are presented to highlight the relative importance of the different processes. It is shown that the main influence that leads to amplification of the initial disturbance is due to wave shoaling and topographic resonance. Although meteotsunamis are not catastrophic to the extent of major seismically induced basin-scale events, the temporal and spatial occurrence of meteotsunamis are higher than those of seismic tsunamis as the atmospheric disturbances responsible for the generation of meteotsunamis are more common. High-energy events occur only for very specific combinations of resonant effects. The rareness of such combinations is perhaps the main reason why destructive meteotsunamis are exceptional and observed only at a limited number of sites globally.

Tsunamis: bridging science, engineering and society

“…According to Pattiaratchi & Wijeratne's [13] review, meteotsunamis are multi-resonant phenomena, but primarily occurring when the speed of the atmospheric disturbance is close to equal the local shallow water wave celerity, then due to topographic resonance. All possible resonances depend in the bathymetry and geology of the coastline, while their timing with respect to tidal elevation or mean sea level (including storm surge) dramatically changes their impact.…”

“…While of course a single data point is not sufficient to draw general conclusions, it is noteworthy that the highest water level in 115 years from a meteotsunami was recorded in Fremantle, Western Australia. Pattiaratchi & Wijeratne [13] analysed weather and wave data from 25 events in 2014 and found that most occurred in winter, as cold fronts move onshore. The speculation is that, while the numbers may decrease as high-pressure belts expand during global warming, the resulting extreme wave heights due to meteotsunamis will increase.…”

Meteotsunamis in the northeastern Gulf of Mexico and their possible link to El Niño Southern Oscillation

“…Because meteotsunamis are shallow water waves over the shelf and coastal regions (wavelength C20 times the local depth), their amplitude can be affected by reflection, refraction, shoaling, diffraction and harbor resonance. Pattiaratchi and Wijeratne (2015) reviewed the occurrence of meteotsunamis worldwide with the aim of determining whether these ocean waves are an underrated hazard. They concluded that the probability of meteotsunamis worldwide is higher in general because energetic atmospheric disturbances are more probable than tsunamigenic earthquakes.…”

Towards an understanding and operational early warning of the Adriatic meteotsunamis: Project MESSI

“…Next, Meteorological and Hydrological Service will benefit from investigation a process which require non-standard meteo measurements, thus Features, processes, evolution and problems setting new standards for its operational forecast. The Mediterranean, European and world community in operational oceanography will benefit, as meteotsunamis are perceived as an underrated hazard that occur throughout the oceans (PATTIARATCHI & WIJERATNE, 2015). Various national ministries and civil protection agencies should be interested for project products, as being which are potential governmental users and possible organisers/sponsors for the establishment and maintenance of an operational oceanography centre.…”

“…Travelling air pressure disturbances are the most common generator of meteotsunamis, where the energy is transferred from the atmosphere to the ocean through a number of resonances, of which most common are Proudman resonance (PROUDMAN, 1929) and harbour resonance (RABINOVICH, 2009). At the top of a harbour these sea level oscillations can range for several metres and can flood coastal areas (VUČETIĆ et al, 2009), damage coastal infrastructure (JANSÀ et al, 2007;PATTIARATCHI & WIJERATNE, 2015), and injure and kill the people (HIBIYA & KAJIURA, 1982;BECHLE et al, 2016). Meteotsunamis has been documented to occur worldwide, while being particularly destructive in micro-tidal regions, where the coasts and the infrastructures are not adapted to large and rapid sea level oscillations.…”