Far-Field Tsunami Observations of the 29 July 2025 Mw 8.8 Kamchatka Earthquake and Comparison with other Far-Field Tsunamis on the Mexican Pacific Coast

The Mw8.8 Kamchatka earthquake occurred offshore southern Kamchatka on July 29, 2025, generating a tsunami that propagated across the Pacific Ocean and produced a measurable sea-level disturbance along the Mexican Pacific coast. In this study, we analyze tide-gauge records along this coast to document the arrival times, duration, maximum wave-heights, and spatial variability of this far-field tsunami. The first tsunami signal reached the northern Mexican coast approximately 9.5 h. after the earthquake, initially detected at Ensenada, Baja California, followed by subsequent arrivals at stations farther south. Maximum recorded wave-heights ranged from 0.13 m to 0.76 m, with the highest values observed at Manzanillo, Acapulco, Zihuatanejo bays, Salina Cruz, and Puerto Chiapas. Spatial variability in wave heights along the coast may reflect the combined influence of basin-scale propagation, coastal orientation, local bathymetry, and site-specific coastal effects. At several stations the largest oscillations occurred during later wave groups rather than during the first arrival, and measurable tsunami energy persisted for more than 24 h. Comparison with historical far-field tsunamis affecting Mexico, including the 1960 Chile, 1964 Alaska, and 2011 Tohoku events, indicates that the long-distance tsunami impact on the Mexican Pacific coast cannot be explained solely by earthquake magnitude but reflects the combined influence of source characteristics, basin-scale propagation, and local coastal response. These observations provide valuable constrains for evaluating far-field tsunami hazards and improving tsunami monitoring and warning strategies in Mexico.