August 4, 1856 Earthquake: Coast, Honduras

August 4, 1856, 16:47 [local time]. Suddenly, an earthquake destroyed settlements on the Atlantic coast of Honduras, approximately from Omoa to Beliz. The port of Omoa was almost totally destroyed. Many cracks appeared in the walls of the ancient Spanish fortress. The ground cracked in a radius of 50 km (12 leagues) in the vicinity of the city and on the coast between the Rio Tinto and Ulua Rivers. The town of San Jose was also destroyed, and Beliz suffered damage. Weak tremors lasting 30 seconds were felt at Guatemala. Underground shocks lasted all the night of the 4th-5th. Then for a week more than a hundred were counted, and they lasted at least until the 27th. The Indian tribes of Honduras long remembered this earthquake. At Omoa, the sea fell and rose to a height of 5 m in still weather; it reached the foot of the fortress and added to the destruction begun by the earthquake. A similar phenomenon was observed on the shore of Criba lagoon. (ref #415)

August 4-14, 1856. Gulf of Honduras. The Honduras coast from the banks of the Rio Tinto (Gracias a Dios dept.) to that of the Rio Ulua and Omoa (Cortes dept.), Livingston, Santo Tomas, Belize, Jamaica, Guatemala City.

Description. Omoa, Aug 9, of 1856 [date of report by Bogran]. The full neighbourhood of the greater consternation abandoned the houses and settled down in tents in the streets, where it has happened all night of the 4 and all of the 5, of where diseases have been followed. The tremors have continued with but or less frequency from the 4 to the hour mentioned, to today [August 9] to 7 in the morning, but nevertheless of ..., no has been nor like the quarter of first [August 4]: this has been the frightful one, the one that has inflict casualties all the indicated, and only has made great and deep cracks on both sides of the population, in an in line straight extension as of twelve leagues from the bar of Red River, to the one of the Ulua... The houses but not the population were damaged... At those moments one has seen rare phenomena, as much in the sea as in earth. This towards undulations so pronounced as the sea; and the sea agitated as much that I evaluate myself as three varas [33 inches] on its level (Bogran 1856)...

Anthony makes clear that an obvious tsunami was not "generated all along the Caribbean coast" but just near the Rio Patuca. However, at Omoa the sea rose 5 m. at the base of the fort.

R. A. White states that ... based upon reports, almost certainly 1856 was a rupture on the Swan fracture zone. It must have extended from Omoa, Honduras, to or nearly to the Cayman spreading center, which is about 365 km west of Jamaica and represents a rupture length of 500 to 600 km. Based upon a comparison with similar earthquakes, such as the 1906 San Francisco earthquake, I estimate a magnitude of 8.3 +02. (ref #103)

Aug 4, 1856. Honduras, Omoa, San Jose. Intensity III which corresponds to an earthquake which destroyed towns and devastated districts. (ref #1055)

[…] and were somewhat surprised to find, instead of a wild animal, an immense crack in the bank -one of the effects of the earthquake. Though but a few inches in width, it extended along the river about two hundred feet; then crossing, we traced its course on the other side, stretching far over the hill, in an irregular course, and finally losing itself in the distance. (ref #11627)

...When they returned in the evening, they found it [San Jose] in ruins and almost depopulated. The earthquake had overturned all the houses, with the exception of perhaps 20, although these were severely damaged; All constructions in masonry, without excepting the massive church, were nothing but heaps of rubble. The majority of the inhabitants had perished; and the survivors, kneeling on the ruins of the city, formed groups around the ecclesiastics, who proclaimed the scourge a punishment coming from God and exhorting penance. (ref #11643)