The eruption started modestly. On April 5, 1815, after two years of puffs and burps, Mt. Tambora launched a thick column of ash, pumice, and gas into the sky. For people living near the foot of the massive Indonesian volcano, the view was spectacular, but the fallout was merely a nuisance - good for the soil.
Five days later, however, in the early evening, Tambora exploded in the largest volcanic eruption in history. For the first three hours, ash and dust hurtled into the sky in a roiling cloud some 26 miles tall. Then, much of the cloud collapsed back onto the mountain, sending a thick, searing avalanche of ash, dust, and rock tumbling down the slopes at Autobahn speeds, burying everything in its path.
Now, a team of US and Indonesian volcanologists say they have unearthed evidence of a town buried under the eruption's debris. They suggest that it may be the political center of the small kingdom of Tambora, which had a population of roughly 10,000 at the time of the eruption.
So far, the team has unearthed the charred beams of a house and the remains of two occupants, some bronze and iron tools, and uniquely decorated ceramic and porcelain vessels. They've also found glass artifacts fused and distorted by the heat of the debris that swept through the area. The ceramics hint that Tamborans had some sort of direct or indirect ties with Cambodia and Vietnam, according to Haraldur Sigurdsson, a University of Rhode Island volcanologist who led the effort.
The ties may have been cultural as well. According to records gathered by British officials at the time, Tamborans spoke a language that appeared unrelated to any other Indonesian dialect. It seemed more closely related to the Mon-Khmer family of languages spoken throughout Southeast Asia. Tambora, Dr. Sigurdsson says, "could be the Pompeii of the East."
Based on the evidence so far, some researchers are skeptical that Tambora was a kingdom in the classic sense of the word. But that doesn't diminish the site's value, they add.
"No research has been done by professional archaeologists on the effects of the Tambora eruption as far as I am aware," notes National University of Singapore archaeologist John Miksic in an e-mail. "So this is a useful contribution."
Tambora's effects were far-reaching. The 1815 eruption released 100 cubic kilometers of magma and left a caldera nearly five miles wide and 1,250 feet deep. (By comparison, Mt. St. Helens ejected about half a cubic kilometer of magma during its 1980 eruption.) The original summit of the 37-mile-wide mountain reached nearly 14,000 feet; after the eruption, the mountain stood just over 9,000 feet tall.
Ultimately, Mt. Tambora's eruption killed 117,000 people, either directly, through the surge of pyroclastic material down the slopes and the fallout that collapsed houses on nearby islands, or indirectly, through famine after the fallout buried fields and fouled water supplies.
Tambora's reach was global. It vaulted 400 million tons of sulfur dioxide high into the stratosphere, where it was carried around the world. The compound formed sulfate aerosols, which reflect sunlight back into space. The next year, 1816, would become known as the "the year without summer." The unusually cool climate led to crop failures and famine worldwide.
Sigurdsson, a native of Iceland, has a longstanding interest in the impact of volcanoes on culture. He has worked at Pompeii and Herculaneum in Italy (both buried in 79 AD when Mt. Vesuvius erupted), as well as at the site of the 1982 eruption of El Chichon in Mexico. Tambora's remoteness and the scant scientific record of such an important eruption proved an irresistible lure.
Sigurdsson says he made his first trip to the island in 1986 with a colleague to begin seeking answers to some of the fundamental geological questions about the event. Historical records indicated that the town of Tambora was near where the two scientists were working. At the time it existed, the area was known for its horses, honey, sandalwood, and sappan-wood, which was used to make red dye.
Sigurdsson returned to the island in 2000 to continue his work. There, one of his guides described a gully where people had been finding pottery shards, bones, and bits of bronze. It lay some 16 miles west of the volcano's caldera.
On the last day of the trip, with a boat scheduled to pick the team up the next morning, he and his colleagues set out to find the gully. "It was 5 p.m., and we had to do a 'death march' to get there before dark," he says. What he saw was enough, he says, "to convince me that I had to come back here, that this was a very promising place."
Excavations during a return trip in 2004 yielded the carbonized remains of house beams and the foundation stones around which they collapsed. Scientists also found iron, bronze, and ceramic artifacts, as well as other evidence of human habitation.
Despite the tropical setting, "it didn't rain a drop during the time we were there," says Lewis Abrams, a University of North Carolina geophysicist who worked with Sigurdsson that year, adding that the lack of rain was vital in allowing the team to excavate the house's remains from the gully bed.
Sigurdsson says he hopes to return next year with his team to map the area more fully with ground-penetrating radar, magnetometers, and other remote-sensing tools. Then, he says, he hopes professional archaeologists will pick up the baton, relegating him to more of a supporting role in setting the geophysical context for the area.
Indeed, the work "presents a wonderful opportunity," notes University of Hawaii's Miriam Stark, a professor who specializes in Southeast Asian archaeology. "We need more professional and systematic archaeological work done on the European period across Southeast Asia."