Tambora

Tambora, volcano in south central Indonesia, on the northern arm of the island of Sumbawa, which lies in the middle of the Malay Archipelago. On April 5, 1815, Tambora exploded in what has been the largest observed volcanic eruption of the last two centuries. Before the eruption, Tambora was about 4,000 m (13,000 ft) tall; after the eruption, which lasted five days, the mountain was about 2,850 m (9,350 ft), with a crater measuring 31 sq km (12 sq mi) in area and 1,300 m (4,000 ft) deep.

The eruption shot forth more than 150 cu km (more than 40 cu mi) of debris, depositing ash over everything within 1,000 km (600 mi) of the mountain. Agricultural land was ruined, and up to 10,000 people were killed, including 8,000 in nearby Tambora and Pekat. In addition, about 66,000 people either died later of starvation or disease or were forced to move to safer, unpolluted land farther from the mountain. The debris also coated the stratosphere, from 15 km to 50 km (10 mi to 30 mi) above Earth, where it blocked up to one-fifth of the Sun’s light and heat. The reduction of light and heat may have played a part in the slow growth of crops, bad harvests, and unusual weather patterns worldwide in 1815. In the northeastern United States, the weather was unseasonably cold, with snow and frost through June. In the British Isles and Scandinavia, almost continuous rain from May to October and lower temperatures than normal resulted in poor harvests and food shortages.

Today, a lake occupies Tambora’s vast crater. From the volcano’s rim, there are extensive views of Sumbawa and the neighboring island of Lombok.