August 3, 1951 Earthquake: Potosi, Gulf of Fonseca, Nicaragua

On August 3, 1951, strong earthquakes split open the sides of the long dormant Cosiguina volcano, inactive since 1835, sending tons of water crashing down from a crater in its center and inundating the small Pacific coast port of Potosi. The town of about 1,000 population was virtually destroyed and casualties were believed to be heavy. Potosi was operated as a U.S. Navy base during World War II. Disrupted telephone and telegraph lines prevented communication with the stricken area. The Survey gives the time of the main shock as 00h 23m 58s, U.T.C., with a foreshock on August 2 at 20h 30m 17s and an aftershock on August 3 05h 25m 45s, with provisional epicenter 13o N, 87.5oW, and depth of focus about 100 km. Pasadena and Berkeley estimate the magnitude of the main shock as 6. Pasadena estimates the magnitude of the foreshock as 5.75, the aftershock as 5.5. This location is near the head of the Gulf of Fonseca. (reference #3828)

Reference #11823:

Fissures many meters in size opened up near the crater causing a great flow of water. Thunderous noises in Telica. Damage reported in Chinandega and Corinto. 12 earthquakes occurred in a few minutes. People slept in the hallways waiting for the possible disaster.

Thursday afternoon one of the earthquakes opened up a fissure 200 meters long in the farm "Las Pozas", near Potosi in Cosiguina. The moment the fissure opened a huge flow of water emerged inundating the entire area, leaving the inhabitants in a panic. The water came out in huge waves from inside of the fissure.

16 earthquakes in Chinandega, the last occurred at 6 in the morning.

The earthquakes started in the western part of the country and southwest of Honduras around 11:45 in the morning on Thursday. In the cities of Chinandeag and Chichigalpa the ground shook at that time during a windstorm that left trees on the ground and damaged sesame farms.

Thursday night the ground shaking caused the destruction of 3 houses in Chinandega.

The earthquakes have impacted most the southwest zone of Honduras and western Nicaragua and with less intensity, according to cables, other parts of Central America with the exceptions of Guatemala and El Salvador where the first hours of Thursday night 3 strong earthquakes were felt.

In the following places the earthquakes were felt strongly in the last 48 hours: Somotillo, Estelí, Sébaco, Matagalpa, Chinandega, El Paraíso (Honduras), Chichigalpa, León Jinotega, Nva. Segovia y Managua.

Managua. - In the capital the shaking was felt strongest. The first was felt at 2:45pm; again at 6:30pm and again at 11:30pm.

Yesterday another movement was felt at 5:15am and a stronger movement at 10:55am. It was felt with less intensity on the western part of the country (where it seems the epicenter of the disaster was) the population is still afraid remembering the 1931 earthquake as well as the recent comments made by volcanologist Ray Wilcox that Managua was sitting on an "egg shell", surrounded by lagoons and underground currents/streams of water.

In Leon, our correspondent informed us that following two earthquakes a strong electrical storm occurred and further panicked the public.

From Chinandega we've received additional details that the day before the earthquakes (Wednesday) a significant amount of rain fell during a windstorm that knocked down a railing at the Palacio Departamental and caused damages to various houses.

1951 August 4 La Prensa Newspaper.