May 7, 1822 Tsunami: Matina, Costa Rica

A local tsunami was reported at Matina. The rivers and bays experienced flooding (possible description of a tsunami). (reference #53)

1822, May 7. 9.5 N, 83 W, magnitude 7.6 Ms. Matina, Costa Rica. (reference #273)

in Matina three shocks were felt as violent as no neighbor remembered having ever felt; the shaking continued almost for twenty-four hours without interruption [...] the rivers and bays grew and caused floods; that the neighbors decided to come to Cartago. (reference #1539) (Note: unofficial translation)

7 May 1822 – Confirmed tsunami. [Reference #1539] reports from historic papers that “in (Boca) Matina there were three violent shakes as no resident remember to had felt before; […] that the rivers and bay grew and caused floods” (p. 21; translated by the authors). The flooding caused by rivers can be explained by plugging caused by landslides consequence of the earthquake, but the “grew” of the bay and its subsequent flooding can only be explained as a tsunami. (reference #12928)

The observations that have been interpreted likely indicate the occurrence of a tsunami associated with the San Estanislao earthquake, suggesting that this event had a reverse fault rupture mechanism, similar to that of the 1991 earthquake and also we can conclude that the hypocenter is located on the Caribbean side of the southern countries of Central America. Likewise, the damage distribution clearly shows that the hypocenter must have occurred in the Caribbean region of Costa Rica. (reference #12929) (Note: unofficial translation)