Meteorological tsunamis on the coasts of British Columbia and Washington

Abstract Tsunami-like sea level oscillations recently recorded by tide gauges located at offshore, as well as sheltered, sites along the coasts of British Columbia (Canada) and Washington State (USA) are identified as meteorological tsunamis. The events resemble seismically generated tsunamis but have an atmospheric, rather than seismic, origin. The event of 9 December 2005 was sufficiently strong to trigger an automatic tsunami alarm, while other events generated oscillations in several ports that were potentially strong enough to cause damage to marine craft. Analysis of coincident 1-min sea level data and high-frequency atmospheric pressure data confirms that the events originated with atmospheric pressure jumps and trains of atmospheric gravity waves with amplitudes of 1.5–3 hPa. The pronounced events of 13 July 2007 and 26 February 2008 are examined in detail. Findings reveal that the first atmospheric pressure event had a propagation speed of 24.7 m/s and an azimuth of 352°; the second event had a speed of 30.6 m/s and an azimuth of 60°. These speeds and directions are in close agreement with high-altitude geostrophic winds (the jet stream) indicating that the atmospheric disturbances generating the tsunami-like sea level oscillations are likely wind-transported perturbations rather than freely propagating atmospheric gravity waves.

[1]  Toshiyuki Hibiya,et al.  長崎湾におけるあびき現象 (湾内の大規模なセィシュ) の発生機構 , 1982 .

[2]  Joaquín Tintoré,et al.  Pressure-Forced Seiches of Large Amplitude in Inlets of the Balearic Islands , 1993 .

[3]  D. Belušić,et al.  Source of the 2007 Ist meteotsunami (Adriatic Sea) , 2009 .

[4]  A. Rabinovich,et al.  Longwave Measurements for the Coast of British Columbia and Improvements to the Tsunami Warning Capability , 2004 .

[5]  I. Vilibić,et al.  Teleconnections between the Adriatic and the Balearic meteotsunamis , 2009 .

[6]  S. Monserrat,et al.  On the reconstruction of the transfer function for atmospherically generated seiches , 1998 .

[7]  A. Rabinovich,et al.  Tsunamis on the Pacific Coast of Canada Recorded in 1994–2007 , 2009 .

[8]  J. Lander,et al.  Tsunamis Affecting the West Coast of the United States: 1806-1992 , 1993 .

[9]  John B. Herbich,et al.  Handbook of coastal and ocean engineering , 1990 .

[10]  S. Monserrat,et al.  Atmospheric gravity waves and the ‘Rissaga’ phenomenon , 1991 .

[11]  K. Iida,et al.  Tsunamis: Their Science and Engineering , 1983 .

[12]  N. Leder,et al.  Resonant coupling of a traveling air-pressure disturbance with the east Adriatic coastal waters , 2004 .

[13]  John J. Clague,et al.  Tsunami Hazard and Risk in Canada , 2003 .

[14]  Sebastià Monserrat,et al.  Meteorological tsunamis near the Balearic and Kuril Islands: Descriptive and statistical analysis , 1996 .

[15]  A. Rabinovich,et al.  Double jeopardy: Concurrent arrival of the 2004 Sumatra tsunami and storm‐generated waves on the Atlantic coast of the United States and Canada , 2007 .

[16]  A. Rabinovich.  Seiches and Harbor Oscillations , 2009 .

[17]  A. Dziewoński,et al.  A technique for the analysis of transient seismic signals , 1969 .

[18]  R. Greatbatch,et al.  Barotropic waves generated by storms moving rapidly over shallow water , 2002 .

[19]  Ivica Vilibić,et al.  Meteotsunamis: atmospherically induced destructive ocean waves in the tsunami frequency band , 2006 .

[20]  S. Alonso,et al.  A Theoretical Study of Large Sea Level Oscillations in the , 1988 .

[21]  Richard E. Thomson,et al.  Oceanography of the British Columbia Coast , 1981 .

[22]  William H. Hooke,et al.  Waves in the atmosphere , 1975 .

[23]  J. Gower,et al.  Vortex Streets in the Wake of the Aleutian Islands , 1977 .

[24]  William J. Emery,et al.  Data Analysis Methods in Physical Oceanography , 1998 .

[25]  T. Hibiya,et al.  Origin of theAbiki phenomenon (a kind of seiche) in Nagasaki Bay , 1982 .

[26]  I. Vilibić,et al.  Destructive meteotsunamis along the eastern Adriatic coast: Overview , 2009 .

[27]  S. Monserrat,et al.  Generation of Meteorological Tsunamis (Large Amplitude Seiches) Near the Balearic and Kuril Islands , 1998 .

[28]  D. Belušić,et al.  Detecting and following atmospheric disturbances with a potential to generate meteotsunamis in the Adriatic , 2009 .

[29]  S. Monserrat,et al.  Use of Ducting Theory in an Observed Case of Gravity Waves , 1996 .

[30]  Richard E. Thomson,et al.  The Sumatra tsunami of 26 December 2004 as observed in the North Pacific and North Atlantic oceans , 2006 .

[31]  I. Vilibić,et al.  Numerical Modelling of the Destructive Meteotsunami of 15 June, 2006 on the Coast of the Balearic Islands , 2008 .