1 August 2017
Santa Marta: a landslide induced tsunami on 19th July 2017
On 19th July 2017 a small tsunami struck the area around Santa Marta on the Caribbean coast of Colombia. Although this event has received little attention, it was captured on a couple of Youtube videos. The raw footage on this video is probably the best:-
Whilst this news report provides that footage and some additional shots as well:-
This tsunami caused some localised damage but fortunately no loss of life. The Colombian Maritime Agency have put out a press release about the event (in Spanish) that includes tide gauge data from Santa Marta that clearly shows the tsunami:-
The report notes that the tsunami had a maximum height of about 50 cm, but that it was not associated with a seismic event or any meteorological phenomenon, suggesting that the most likely cause was a submarine landslide event.
This is the Google Earth imagery of this area of the Caribbean:
Immediately offshore from Santa Marta is the La Aguja submarine canyon, the location of which is shown on the Google Earth imagery above. This is a site that has been identified as being prone to submarine landslides in the past. Retrespo-Correa and Ojeda (2010) provided a description of this canyon:-
La Aguja submarine canyon (ASC) is located off the northern shore of the 5.7-km high Sierra Nevada de Santa Marta (Fig. 1). The canyon extends 115 km down the entire shelf and continental slope, with depths ranging from −10 m to −3200 m. The canyon’s width varies from 2 to 6 km and its mean thalweg slope is 0.9°.
Vargas and Idarraga-Garcia (2013) identified 31 submarine landslides along the length of the La Ajuga submarine canyon, aged between 632,000 years before present to less than a thousand years ago. Given the location of this tsunami, a good initial hypothesis might therefore be a submarine landslide in the La Ajuga submarine canyon.
Restrepo-Correa I.C. and Ojeda G.Y. 2010. Geologic controls on the morphology of La Aguja submarine canyon. Journal of South American Earth Sciences 29:861–870.
Vargas, C.A. and Idarraga-Garcia, J. 2013. Age estimation of submarine landslides in the La Ajuga Submarine Canyon, Northwestern Colombia. In: Advances in Natural and Technological Hazards Research, 37; 629-638; Submarine mass movements and their consequences. Springer.