The 8.2 Mw  Tumaco earthquake shakes Colombia and Ecuador with a maximum Mercalli intensity of IX (Violent), killing 300–600, and generating a large tsunami.

The 1979 Tumaco earthquake occurred at 02:59 local time on 12 December with a moment magnitude of 8.2 and a maximum Mercalli intensity of IX (Violent). The epicenter was just offshore from the border between Ecuador and Colombia, near the port city of Tumaco. It triggered a major tsunami, which was responsible for most of the estimated 300–600 deaths. The hardest hit area was Colombia's Nariño Department.

Colombia, officially the Republic of Colombia, is a country primarily located in South America with insular regions in North America. The Colombian mainland is bordered by the Caribbean Sea to the north, Venezuela to the east and northeast, Brazil to the southeast, Peru and Ecuador to the south and southwest, the Pacific Ocean to the west, and Panama to the northwest. Colombia is divided into 32 departments. The Capital District of Bogotá is also the country's largest city hosting the main financial and cultural hub. Other major urban areas include Medellín, Cali, Barranquilla, Cartagena, Santa Marta, Cúcuta, Ibagué, Villavicencio and Bucaramanga. It covers an area of 1,141,748 square kilometers and has a population of around 52 million. Its rich cultural heritage—including language, religion, cuisine, and art—reflects its history as a colony, fusing cultural elements brought by immigration from Europe and the Middle East, with those brought by the African diaspora, as well as with those of the various Indigenous civilizations that predate colonization. Spanish is the official language, although Creole, English and 64 other languages are recognized regionally.

Ecuador, officially the Republic of Ecuador, is a country in northwestern South America, bordered by Colombia on the north, Peru on the east and south, and the Pacific Ocean on the west. It also includes the Galápagos Province which contains the Galápagos Islands in the Pacific, about 1,000 kilometers (621 mi) west of the mainland. The country's capital is Quito and its largest city is Guayaquil.