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The major (Mw 8.2) intraplate normal-fault earthquakeof 8 September 2017 in the Gulf of Tehuantepec (Chiapas,Mexico) generated a strong tsunami that severely impacted thenearby coasts of Mexico and Central America. Tsunami waves inthe near-field area were measured by seventeen high-resolutioncoastal tide gauges and by three open-ocean DART stationsanchored offshore from the affected region. Data from these sites,together with those from four distant DARTs, were used forcomprehensive analyses of the 2017 event. De-tided sea level timeseries were examined to determine the statistical and spectralcharacteristics of the 2017 tsunami waves along the Mexican andCentral American coastline. The characteristics of the recordedwaves from this near-field event were compared with those fromtwo great far-field events: the 2010 Chile and the 2011 Tohokutsunamis. Maximum trough-to-crest wave heights for the 2017tsunami were recorded at Puerto Chiapas (351 cm), Salina Cruz(209 cm), Acapulco (160 cm), Huatulco (137 cm) and Acajutla, ElSalvador (118 cm). While maximum 2010 and 2011 tsunami waveswere observed at specific ‘‘hot spots’’ (sites with a high Q-factorand pronounced resonant properties, such as Manzanillo andAcapulco), the ‘‘strengths’’ of the recorded 2017 tsunami waveswere mostly determined by distance from the source. Contrary tothe maximum wave heights, the general spectral properties of thetsunami signals for all three events were highly similar at a givencoastal site and mainly resemble the spectral structure of backgroundoscillations at the same site. This similarity indicates thatthe frequency properties of the tsunami waveforms for a steadystatetsunami signal are mainly determined by local topographicfeatures rather than by the source parameters. Estimates of the‘‘colour’’ of an event (i.e., the open-ocean tsunami frequencycontent) show that the 2017 Chiapas tsunami was mostly ‘‘reddish’’(long-period), with 68% (DART 43413) to 87% (DART 43412) ofthe total tsunami energy related to waves with periods[35 min. Incontrast, the 2010 and 2011 tsunamis were ‘‘reddish-blue’’, with48–57% associated with long-period waves ([35 min) and52–43% with short-period waves (2–35 min). The dominantperiods of the tsunami waves were mostly linked to the shape,length, and width of the source region: the larger the source and theshallower its depth, the longer the periods of the generated tsunamiwaves. The complicated structure of the source explains the saturatedand wide frequency-band character of the tsunami spectra.Our analysis also reveals an anisotropic nature to the 2017 tsunamiwaves; waves that propagated northeastward along the mainlandcoast of North America and southeastward along the CentralAmerican coast were significantly different from those that propagatedsouthwestward, normal to the source orientation. Thisaspect of the wave field appears to be related to two distinct typesof waves; ‘‘trapped (edge) waves’’ retained on the shelf (whichplays the role of a ‘‘wave guide’’), and ‘‘leaky waves’’ that radiateinto the open ocean.

Palabras clave: 2017 Chiapas earthquake and tsunami, Mexico,; Central America, Tide gauges, DART, Time series analysis,; Spectra, Tsunami parameters, 2010 and 2011 tsunamis

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