THE LITTLE (VOLCANIC) ICE AGE - Tambora: The Eruption that Changed the World - page 20

power only, not the climatic impact of the volcano. The famous Mount St. Helens eruption in
1980, for example, rates a respectable 3 on the VEI, but since its volcanic matter ejected side-
ward and not upward into the stratosphere, its impact on climate was nil. As we have seen,
the latitude of volcanoes is also crucial to their climatic impact: tropical volcanoes are cap-
able of influencing global weather patterns while high-latitude volcanoes, such as Iceland's
Laki in 1783, impact only the northern hemisphere. But the VEI takes no account of latitude.
Hence the recent development of an alternative index of volcanic measurement based on
ice core data—the paleoclimatologist's time travel machine. Historical accounts might reach
back centuries, tree-ring data a little further, and geological evidence never see the light of
day, but the new Ice-Core Volcano Index (IVI), through identification of sulfur isotope an-
omalies in polar and mountain ice, offers a trans-millennial measure of ash deposition in the
earth's remote glacial archives. 24 Call it the volcanic Hall of Fame. Only eruptions that obtain
stratospheric height, and hence climatic significance, find their immortal reward in the ice.
The status of Tambora according to the IVI is more complicated than under the old Smith-
sonian regime. Tambora's ranking as the largest eruption of the second millennium has been
challenged by partisans of other major eruptions of the Little Ice Age, including the 1258
Unknown, Mount Kuwae in 1452, and the 1600 eruption of Huaynaputina in Peru. The de-
bate in the volcano-climate community over the relative magnitude of Holocene and Little
Ice Age eruptions will surely continue, with fresh claims and counterclaims year by year. For
the purposes of this topic, however—standing as it does at the ceremonial eve of Tambora's
bicentenary and based on the scientific evidence currently available—I invite the reader to
think of Tambora's eruption as a thousand-year volcanic event, and among the very largest
since human civilization emerged at the dawn of the Holocene twelve thousand years ago.
After years studying Tambora, when I ponder its relation to other volcanoes, my thoughts
do not turn to Vesuvius, destroyer of Pompeii, nor to the great 1258 Unknown, purported
trigger of the “Little Ice Age,” nor to Krakatau, volcanic darling of the Victorians. I think in-
stead of a volcanic legend with far deeper historical DNA. The cataclysmic eruption of San-
torini in the Aegean Sea in 1628 BC has been linked to the collapse of Minoan civilization, the
legend of Atlantis, and the Israelites' exodus from plague-ridden Egypt as told in the Bible. 25
An awe-inspiring list, but the tale of Tambora will more than match it. The chapters that
follow make the case for Tambora's 1815 eruption as a world-historical event on the order
of Santorini's explosion three-and-a-half millennia ago, wreaking, through sinuous courses,
comparable changes on global humanity and the totemic mind.