The Tierra Blanca Joven eruption of Lake Ilopango was the largest volcanic eruption in El Salvador during historic times, and one of the largest volcanic events on Earth in the past 7,000 years, registering at 6 on the Volcanic explosivity index (VEI), and dating back to the mid 5th century A.D.

The eruption produced between 37–82 km3 (8.9–19.7 cu mi) of ejecta (dense-rock equivalent).

[2][3][4] The date of the eruption has been constrained within 429–433 CE by identifying its signature volcanic ash in precision-dated ice cores sampled from Greenland, thus eliminating it as the cause of extreme weather events of 535–536.

[5] It produced about 104–207 km3 (25–50 cu mi) of tephra (several times as much as the 1980 eruption of Mount St. Helens), produced major pyroclastic fall and large pyroclastic flows that covered 10,000 km2 (3,900 sq mi) with over 50 cm (20 in) of pumice and ash,[1] and nearly 2,000,000 km2 (770,000 sq mi) with a blanket of ash at least 0.5 cm (0.20 in) in depth.

[2] The eruption devastated an area of up to 100 km (62 mi) radius around the volcano.