Mysterious tsunami in the Caribbean Sea following the 2010 Haiti earthquake possibly generated by dynamically triggered early aftershocks

Earth and Planetary Science Letters
By: , and 

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Abstract

Dynamically triggered offshore aftershocks, caused by passing seismic waves from main shocks located on land, are currently not considered in tsunami warnings. The M7.0 2010 Haiti earthquake epicenter was located on land 27 km north of the Caribbean Sea and its focal mechanism was oblique strike-slip. Nevertheless, a tsunami recorded on a Caribbean Deep-Ocean Assessment and Reporting of Tsunami (DART) buoy and a tide gauge produced runup heights of 1–3 m along Haiti southeast coast. Earthquake finite-fault model inversions of the DART waveform suggest that a reverse fault doublet with magnitudes of M6.8 and M6.5 located 85 km southwest of the epicenter may have excited the tsunami. This doublet collocates with dynamically triggered aftershocks, derived from back-projection analysis, that occurred 20-60 s after the main shock of the Haiti earthquake. The aftershocks are within a region of maximum dynamic strain predicted by the main shock, on a possibly tectonically active submarine ridge southwest of Haiti's Southern Peninsula. The agreement between the tsunami finite-fault source models and the seismic and tectonic evidence suggests that earthquakes on land, even strike-slip faults, can generate tsunamis by dynamically triggering offshore aftershocks.

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    Additional publication details

    Publication type Article
    Publication Subtype Journal Article
    Title Mysterious tsunami in the Caribbean Sea following the 2010 Haiti earthquake possibly generated by dynamically triggered early aftershocks
    Series title Earth and Planetary Science Letters
    DOI 10.1016/j.epsl.2020.116269
    Volume 540
    Year Published 2020
    Language English
    Publisher Elsevier
    Contributing office(s) Woods Hole Coastal and Marine Science Center
    Description 116269, 11 p.
    Country Dominican Republic, Haiti
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