The epicenter was one hundred miles northeast of the city and the earthquake, with a magnitude of 7.5, was powerful enough to kill 25,000 people and destroy most of the homes.
In the early morning hours of February 4, 1976, an earthquake of magnitude 7.5 hit Guatemala City. It was the most destructive that the country had experienced in more than half a century. The epicenter was one hundred miles northeast of the city. There were numerous aftershocks, some of them as lethal as the main one. In all, 25,000 people died, 80,000 were injured, 250,000 homes were destroyed, and about one and a half million were left without homes. Damage was extensive.
Most of the adobe-type structures in the outlying areas of Guatemala City were completely destroyed by the earthquake. Access to or out of the city was stopped by many landslides. Food and water supplies were severely reduced. Some of the areas were without electricity and communication for days. The main shock was followed by thousands of aftershocks, some of the larger ones causing additional loss of life and damage. Shock waves were felt as far away as Mexico City. In neighboring Honduras, the earthquake destroyed parts of three towns near the Guatemalan border and caused flooding and power failures.
The U.S. government provided an immediate $3.6 million in emergency aid, and an additional $15 million came in voluntary contributions from the United States within six days of the quake. The Organization of American States contributed $500,000, and most other Latin American countries sent food, clothing, medical supplies, doctors, and relief experts.
The fault associated with the quake runs east to west from a point about fifteen miles north of Guatemala Cit to Puerto Barrios near the Gulf of Honduras. During an air reconnaissance of the fault zone, USGS scientists observed fault breakage along a one hundred-mile stretch of the fault.
The epicenter of the main shock, where the rupture began, was identified at latitude 15.27 North and longitude 89.25 West, about twelve miles west of Los Amates and south of Lake Izabal. A shorter fault, at right angles to the main one but only four miles west of Guatemala City, added substantially to the damage. In terms of the total amount of energy released by this earthquake, it was only one-sixteenth of the 1906 San Francisco quake. Like California, Guatemala is known as earthquake country.
The fault that caused this one separates the great North American and Caribbean tectonic plates so, when these plates slide past each other as these two did in Guatemala, and as two plates do in California along the San Andreas, faults break and the earth shakes.