EGU2020-7860
https://doi.org/10.5194/egusphere-egu2020-7860
EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Numerical simulation of the July 2010 meteotsunami on the coast of Portugal: Implications for meteotsunami hazard in the NE Atlantic

Jihwan Kim and Rachid Omira
Jihwan Kim and Rachid Omira
  • IPMA, Lisbon, Portugal (jihwan.kim@ipma.pt)

In the NE Atlantic Ocean, the tsunami hazard is mainly associated to large earthquakes occurring along the Azores-Gibraltar plate boundary, to submarine landslides, or even to the flank collapses in the volcanic Islands. The hazard posed by meteotsunami remains less understood in the region. Yet, the Atlantic coasts of Portugal, Spain and France have experienced at least two meteotsunamis on July 2010 and June 2011. On July 6th and 7th 2010, uncommon sea waves were observed along the coast of Portugal. The Portuguese tide-gauge network recorded the sea-level signals showing tsunami-like waves of heights varying from 0.14 to 0.6 m (crest-to-trough) and of periods in the range of 30 to 60 min. Analysis of both oceanic and atmospheric data
revealed the occurrence of a meteotsunami on the night of July 6th that propagated from Lagos, south, up to Viana de Castelo, north. Here, we present the first investigation of the 2010 meteotsunami that struck the coast of Portugal. We use the atmospheric pressure data to force the sea surface and numerically generate the 2010 meteotsunami. We then simulate the 2010 meteotsunami propagation over high resolution bathymetric models using a validated NLSW code. The comparison of the simulated waveforms with the records shows satisfactory agreement of wave heights and periods in most stations. Taking the 2010 event as a reference of meteotsunamis along the Portuguese coast, we provide an insight on the meteotsunami hazard posed by
events propagating from south to north of the country. This is done by considering a 2D Gaussian shape pressure disturbance that propagates along shelf under varying conditions of speed and incident angle. This allows identifying a number of “hot spots” on the coast of Portugal where the focus of meteotsunami energy is favorable. Our results suggest that meteotsunamis present a real threat on the highly occupied Portuguesecoast and therefore should be considered in tsunami hazard and forecasting strategies of the NE Atlantic countries. This work was supported by the FCT funded project FAST- Development of new forecast skills for meteotsunamis on the Iberian shelf (PTDC/CTA-MET/32004/2017).

How to cite: Kim, J. and Omira, R.: Numerical simulation of the July 2010 meteotsunami on the coast of Portugal: Implications for meteotsunami hazard in the NE Atlantic, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-7860, https://doi.org/10.5194/egusphere-egu2020-7860, 2020

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Presentation version 1 – uploaded on 30 Apr 2020
  • CC1: Comment on EGU2020-7860, Jihwan Kim, 06 May 2020
    Helene Hebert (13:03) Are these meteotsunamis frequent in the Atlantic?
    Jihwan : I think this is an important question. I only have data along Portugal, and I could observe meteotsunamis roughly once or twice a year. I think there are many unobserved cases in Atlantic Ocean. 
  • CC2: Comment on EGU2020-7860, Jihwan Kim, 06 May 2020
    Ira Didenkulova (13:04) Did you have atmospheric data for this event?
    Jihwan: For this event, we have atmospheric pressure data. 
  • CC3: Comment on EGU2020-7860, Jihwan Kim, 06 May 2020

    Thomas Zengaffinen NGI (author) (13:04) @Jihwan Kim: Atmospheric pressure jumps is an interesting tsunami source. To what extent do you think can such a moving air pressure jump be compared to a progressing submarine landslide as tsunami source?

    Jihwan: In general, meteotsunamis are rare and the wave amplitude is much smaller than landslide-generated tsunamis. In Portugal, I think the damage from meteotsunamis can be higher. Moreover, we may be able to predict the generation and propagation of meteotsunamis. 

  • CC4: Comment on EGU2020-7860, Jihwan Kim, 06 May 2020

    Denys Dutykh (13:05) @Jihwan Kim: Did you study also the wave run-up caused by these meteotsunami events?

    Jihwan : We studied the wave run-ups and fine grid simulation can also predict port resonance. 

  • CC5: Comment on EGU2020-7860, Jihwan Kim, 06 May 2020

    Helene Hebert (13:06) I was interested in your numerical experiment. Do you foresee any operational use?

    Jihwan : In order to forecast meteotsunamis, we need to have tools to predict the atmospheric disturbance. This disturbance is small-scale event which is difficult for the current atmospheric models. 

  • CC6: Comment on EGU2020-7860, Jihwan Kim, 06 May 2020

    Filippo Zaniboni UniBO (author) (13:07) @Jihwan Kim: did the 2010 event cause any damage on the coast to your knowledge?

    Jihwan : There was no reported damage for 2010 event. The event was mainly early in the morinig, and there were not so many people on the beach. There was another meteotsunami in 2014, and injured people and damaged cars were reported.