December 12, 1979 Tsunami: Off Shore, Pacific Ocean, Colombia

On December 12, 1979 at 07:59:4.3 UTC a major earthquake measuring 7.9 occurred along the Pacific Coast of Colombia. The earthquake and tsunami associated with it were responsible for the destruction of at least six fishing villages and the death of hundreds of people in the Narino State of Colombia. At least 15 other coastal towns in the area were rocked by the earthquake and were damaged by the waves. Waves measuring anywhere from 2-5 meters destroyed many of these coastal villages. People along the coast, who survived the earthquake by running outside their homes, were carried away a few minutes later by the large tsunami waves generated by the earthquake. Six fishing boats, one with 40 men aboard, were lost. A pier on the prison island of Gorgona was destroyed, however, no injuries from either the earthquake or the tsunami were reported from there. Most of the houses at Charco, a village of 4,000 which were built on stilts over a lake were knocked into the water. Waves sent the Iscuande River out of its banks along the Pacific coast. The wall of water reportedly in the village of Iscuande caused extensive damages. At least one person was reported dead from that area.

Hardest hit of all the coastal villages was the fishing village of San Juan, where the waves completely overran the island destroying just about everything in their path. Numerous deaths were reported from San Juan which was totally devastated and is in the process of being relocated further inland at the present time. According to eyewitness reports, 3 to 4 waves were observed, the first wave arriving approximately 10 minutes after the main earthquake. The water recessed first to about 3 meters below the level of the sea. The first wave arrived minutes later. The third wave was the largest, and at San Juan Island it was approximately 5 meters above the level of the tide, which fortunately, was at its lowest at that time.

The maximum difference between low and high tide in the region for that time of the year was approximately 1.3 meters, thus, the maximum wave could have been that much more, if it had arrived at high tide, and numerous more deaths could have resulted. Considering that the mean elevation of the coastal islands is approximately 2 to 2.5 meters above high tide, it would mean that maximum waves would have completely overrun all of the coastal islands in the area. Approximately 30-35 km of the coast was hardest hit by the tsunami, while the length of the area hardest hit by the earthquake was approximately 225 km in length, from Guapi to Tumaco.

It is estimated that the majority of casualties (at least 80%) were the result of the tsunami rather than of the earthquake. An ITIC estimate based on informal reports is that 500-600 people may have been killed by the combined effects of the earthquake and tsunami with about 4,000 people injured. Homes of at least 10,000 persons were destroyed.

(above ref #3330)

The tsunami caused great damage, and was similar in scope to the event of January 31, 1906. Ramirez and Goberna (1980) note that the wave arrived 3 minutes after the earthquake, at San Juan de la Costa. The only death toll from the tsunami is from Tumaco (36 deaths). There may have been other deaths from the tsunami, but they have been included with the earthquake counts by disaster agencies.

Ephemeral Island 10.8N, 75.4W. An island 30 meter long, 5 meter wide and 7 meter high was formed during the night of December 12, 1979 in the Caribbean Sea, 300 meters off the coast of Punta Canoa, Colombia. The sawtoothed island was composed to greenish-gray clay, apparently squeezed upward through a fissure. By Dec 29, the island was only half its initial size and disappeared under the pounding of strong waves on Jan 9, 1980. The Caribbean coast of Colombia is well-known for its mud volcanoes, which have "eruptions" driven by petroleum gases. (ref #11251)