Mount Tambora << TAHM buh ruh >> is a volcano on the island of Sumbawa in the Southeast Asian nation of Indonesia. In April 1815, Tambora produced the most powerful volcanic eruption in recorded history. The eruption buried Sumbawa and nearby islands in volcanic ash and rock, killing tens of thousands of people. Since then, Tambora has experienced several minor eruptions. It remains an active volcano.
Mount Tambora makes up most of Sanggar Peninsula in northern Sumbawa. It rises 9,354 feet (2,851 meters) above sea level, but it stood more than 13,000 feet (4,000 meters) high before the 1815 eruption. After the main eruption, the top of the mountain sank in, forming a vast caldera (craterlike depression) at the summit, measuring 3.7 miles (6 kilometers) in diameter and about 3,609 feet (1,100 meters) in depth.
Tambora’s 1815 explosive eruption was heard over 1,100 miles (1,800 kilometers) away on the western Indonesian island of Sumatra. The eruption expelled more than 36 cubic miles (150 cubic kilometers) of ejecta (ash and rock). Ash from Tambora clouded Earth’s atmosphere, reducing sunlight and cooling temperatures around the planet. In 1816, the cooling caused summer frosts, snowfalls, and frozen rain in areas of the Northern Hemisphere, resulting in crop failures and the so-called “year without summer.”
Scientists rate the explosive power of an eruption using a scale called the Volcanic Explosivity Index (VEI). The VEI assigns eruptions a number from 0 through 8, with 8 being the most powerful. The eruption of Tambora was a VEI 7. The last known VEI 8 eruption occurred more than 26,000 years ago in New Zealand. Scientists base the ratings for past eruptions on the amount of volcanic material ejected in an eruption. They determine the amount by studying rock to map the size and depths of the deposit.
In 2004, scientists discovered the remains of a village buried in volcanic ash near Tambora. Artifacts and parts of the village were preserved by the ash, as were the remains of people killed in the 1815 eruption. The similarity of the Tambora site to that of Pompeii in Italy (destroyed in the A.D. 79 eruption of Mount Vesuvius) has led to its description as “the Pompeii of the East.”
