Simultaneous Occurrence of Local Meteotsunamis and the 2022 Tonga Tsunami along the Argentine and Uruguayan Coasts, Southwestern Atlantic Ocean

Abstract

The Hunga Tonga–Hunga Ha’apai volcano erupted on January 15, 2022, generating atmospheric and oceanic wave responses that were studied along the Atlantic coasts of Argentina and Uruguay, as well as within the Río de la Plata estuary. Following the eruption, a warm front crossed the southeastern South American continental shelf, producing local atmospheric gravity waves (AGWs) that triggered meteotsunami activity. Remote atmospheric waves (Lamb waves) were also observed, arriving with timing consistent with theoretical predictions and displaying uniform waveforms and peak heights across all analyzed locations. However, no evidence suggests that these Lamb waves induced meteotsunamis in the study region. At Puerto Deseado and Bahía Blanca, sea-level disturbances coincided closely with the arrival of the oceanic tsunami generated by the eruption. In the outer Río de la Plata estuary, AGWs associated with the warm front exhibited predominantly southward propagation. This southward progression of meteotsunamis, driven by AGWs generated by the warm front’s passage, supports their local origin.