The quake measured 6.7 on the Richter scale, strong enough to cause significant damage in built-up areas. But the epicenter was about 50 miles from land and 59 miles west-southwest of Mutis, Colombia, the nearest city.
The Alaska Tsunami Center reported no danger of tsunamis.
Residents of much of western Colombia reported feeling the shaking, Colombia Reports said. But there appeared to be no injuries or damage to buildings or other property.