Tambora, Indonesia
There are big eruptions, then there are big eruptions. On April 10, 1815, Tambora, a volcano in Indonesia, produced one of the largest eruptions in human history. This eruption produced what became known as the "year without a summer" after the volcanic aerosols from the eruption produced some of the coldest summers in many parts of the world. The Tambora eruption in 1815 was a VEI 7, on a scale that goes to, well, 7*, putting it in a class of some of the largest and most violent eruptions imaginable - and I, for one, can hardly imagine what might happen if an eruption of this magnitude occurred today.
(*, OK, technically it goes to 8, but those are for eruptions that have never happened in human history, those 1000 cubic kilometer behemoths like Yellowstone.)
Tambora from the International Space Station
Lets get some facts out there about the eruption (taken from Stothers, 1984), just to give us some prespective:
- Total volume erupted: ~150 cubic km of ash, 25 cubic kilometers of ignimbrite (~50 cubic kilometers dense rock equivalent) within the first 3-24 hours - that is an eruptive rate of between 50,000 and 800,000 cubic meters per second. That is only the equivalent of 25,000,000 to 400,000,000 2-Liter bottles of soda erupting every second.
- Ash fell as far as 1300 km / 800 miles from the volcano. How far is that? Drive from Boston to Charlotte, NC. That is how far a measurable quantity of ash was found.
- The sound of the explosion was heard 2600 km / 1600 miles away. This time, drive from Boston to Wichita, Kansas.
- The eruption produced pitch darkness - no light from the sun whatsoever - for 600 km / 375 miles from Tambora. Now, that is only from Boston to near Baltimore.
- The pyroclastic flows from the eruption traveled 20 km / 12 miles from the vent.
- Tsunamis generated by the eruption (most likely the pyroclastic flows hitting the ocean) traveled 1200 km / 750 miles.
- Tambora itself lost 1450 meters / 4800 feet in height and created a ~650 meter / 2100 foot deep crater. That is ~2000 meters / 6900 feet from the old summit to the bottom of the new crater! How much material is that? 30 cubic kilometers of the volcano - gone!
- And the most sobering fact: at least 88,000 people died due the eruption and its aftermath.
Now, that is an eruption that none of us have even come close to experiencing in our lifetime (so far). Tambora - the volcano - was though to be inactive at the time of the eruption. In fact, prior to 1815, the last known eruptive activity was around 740 A.D., although the volcano has shown signs of life as little as 3 years before the cataclysmic 1815 eruption. Since then, Tambora has had two known minor eruptions in 1880 and 1967, both VEI 2 or smaller.
The location of Tambora, map from Stothers (1984)
Timeline of the Eruption
Here is a timeline for the "Great Eruption" of 1815:
- April 5, 1815: Explosions were heard in the area around Tambora - as far away as Batavia (Jakarta), over 1200 km.
- April 6, 1815: Light ash fall, more explosions
- April 10, 1815, 7 PM: Three(?) active vents as the eruption peaked.
- 8-9 PM: The vents coalesce(?) into a single vent of "liquid fire" (according to observers in Tambora, 20 km away. 20 cm pumice and ash falls in Sanggar (30 km). The ash column is believed to have pierced the stratosphere (>17 km / 55,000 feet) - this injected sulfur and other volcanic aerosols into the stratosphere (see below).
- 10-11 PM: "Violent wind" uproots trees in Sanggar. This might be the column collapse of the eruption. A 1-4m tsunami strikes many of the Indonesian Islands.
- After 10PM: Pyroclastic flows and caldera formation. The flows destroyed Tambora (the village). Concussions from the eruption felt over 1000 km away.
- April 11: Loud explosions heard over 2500 km away, ash as far away as western Java and the Celebes Islands. "Nitrous" odor as far as Batavia. A second, smaller tsunami was felt in Madura, north of Java.
- April 12: 80% of the total volume of ash has fallen. It continues to fall in many places until April 17. Explosions stop by April 15, but ash clouds surround the volcano until April 23.
- After April 12-17: Kilometer-wide pumice rafts with uprooted trees found in the ocean. Explosions were reported but not confirmed in August of 1815 and as "flames" were reported (again, not confirmed) as late as 1819.
Climate Effects
The "Great Eruption" produced a what is known as the "Year without a Summer" in 1815 and 1816. The eruption itself is thought to have released 175 trillion kilograms of sulfur aerosols. The ash/dust signal was recorded in both the Greenland and Antarctic ice sheet in tracers like Ba, Bi and Pb concentration, precipitation acidity and other climate tracers. The effect of all these aerosols was a drop in average global temperature between 0.7 and 3 degrees (C), while warming the stratosphere by as much as 15 degrees (K). You could fill volumes with the events of the "Year(s) without a Summer," but I'll just sum it up by saying that Tambora caused an great deal of turmoil - crop failures, famine, acid fogs, cold winters, vivid sunsets and haze throughout the northern hemisphere as far as London, Russia, the United States and beyond. These effects remained for possibly as many as 4 years after the eruption. The eruption had cultural results as the dreary summers in Europe in 1815-16 prompted Mary Shelley to write Frankenstein and allowed J.M.W. Turner to paint some of the stunning sunsets (below) in England during those years. It is interesting to note that Tambora is likely not the only culprit, as 1815-16 also featured a very weak solar maximum that could have caused some of the cooling. Geologists like Haraldur Sigurdsson has been researching the destruction of villages near the volcano (althought "Lost Kingdom" might be a little overstated.)
J.M.W. Turner painting of Chichester Canal in 1816
This barely scrapes the surface of the Tambora 1815 eruption and its effects. If you really want to wade into the eruption, you can check out the following sources:
- de Boer, J.Z. and Sanders, D.T., 2002, 'Volcanoes in Human History' - specifically Chapter 6.
- Self, S. et al., 1984, Volcanological study of the great Tambora eruption of 1815,Geology; v. 12, no. 11, p. 659-663
- Stothers, R.B., 1984, "The Great Tambora Eruption in 1815 and its Aftermath", Science; v. 224, p. 1191-1197.
Physical Science
Environment
Comments (82)
To your bibliography may be added Hank and Elizabeth Stommel's "Volcano Weather: The Story of the Year Without a Summer". Well worth the reading.
Hank (Henry) Stommel was a "pioneering" oceanographer at the Woods Hole Oceanographic Institution, and a splendidly enthusiastic polymath. He's gone now, but Elizabeth is still around, the last I knew.
Further book details: Published 1983 by Seven Seas Press, Newport RI.
ISBN 0-915160-71-4
Posted by: Thomas Hodgson | April 10, 2009 7:15 AM