Long before the phrase “nuclear winter” was coined, the northern hemisphere experienced one.
Modern Americans who reside in the ‘rust belt’ often complain that the summers are too short, or too hot, or too humid. They wouldn’t be so critical had they experienced the summer of 1816, because that year there was no summer. The normal weather patterns experienced in Europe and North America were upended by a cataclysmic event that occurred a year before and half a world away- the explosive eruption of Mt. Tambora. It was probably the deadliest volcanic explosion in recorded history.
History of a Killer
The story of Mt. Tambora, the dominant feature of the island of Sumbawa in Indonesia, begins about 57,000 years ago. Two tectonic plates, enormous sections of earth’s crust that move very slowly, collided beneath the Indonesian archipelago. In a process called subduction, one plate began to slide under the other. Tambora was born out of this process, and grew very gradually through periodic leaking of its magma chamber, which built the mountain up in layers. When this process was completed, Mt. Tambora stood between 13-14,000 feet. It’s magma chamber stopped venting regularly and began to fill up, a process which may have taken centuries.
At some point the magma chamber became full, yet the upward movement of liquid rock did not stop due to the pressures at its source. There inevitably came a time when Mt. Tambora’s magma chamber realized pressures that the structure could not contain; this time arrived during April, 1815.
An Explosion Heard for More Than a Thousand Miles
Mt. Tambora rumbled and smoked during early April, but it had been doing so on and off since 1812. The people of the village of Tambora and Sumbawan Islanders were probably not all that alarmed. After all, generations of them lived in the shadow of the big conical volcano. But the rumblings of 1815 were climaxed by an explosion of a magnitude unmatched since a blast at Lake Taupo in 181 AD, and not equaled since.
The explosive decompression of Mt. Tambora’s magma chamber was heard in Sumatra, 1,200 miles distant. On the modern Volcanic Explosivity Index (VEI), the blast has been rated a seven. This begs comparison to other, similar events. When Krakatoa self-destructed in 1883, the explosion was roughly equivalent to 10,000 Hiroshima-grade bombs. It has a VEI score of 5, as do the eruptions of Mt. Vesuvius in 79 AD and that of Mt. St. Helens in 1980. Mt. Tambora blew with four times the force of Krakatoa.