The Mysterious Eruption of 1258 A.D.

I've blogged before about the Mt. Tambora eruption of 1815, which is one of the most powerful volcanic eruptions in the past 1,000 years. However, Erik Klemetti, who authors the Eruption blog at Wired Magazine, has a couple articles discussing an even larger explosion in 1258 A.D., which is the more interesting because the likely source of the explosion has only recently been identified.

Klemetti wrote last year:

Over the last few weeks, we’ve seen a number of high-profile studies come out looking at global climatethat refer to a mystery. According to ice core and sediment core records from many places on the globe, there was a very large volcanic eruption in 1258 A.D. — so big that it injected somewhere between 190-270 megatonnes into the atmosphere (to put in another way, it produced between 300 and 600 megatonnes of sulfuric acid). This would make the 1258 eruption ~8 times larger thanKrakatau in 1883 and two times larger than Tambora in 1815 (when comparing their sulfate injection mass; Emile-Geay et al., 2008). So, how does the geologic community (or historical community for that matter) not have any record of such an massive eruption that happened less than 800 years ago?
First, I should discuss a little bit of the evidence for the 1258 A.D. eruption. As mentioned above, there is a record of increased sulfur and ash particles in ice cores from both the North and South Poles, along with other places such as sediment from Lake Malawi (Emile-Geay et al., 2008). Now, many of these ice cores and sediment records have been dated, so we can correlate them across the globe (within error). The combined data points towards an eruption that occurred in 1258 (or possibly 1259) – in fact, based on some of the weather records from Europe, the date could be constrained to between January and mid-May 1258 (Stothers 2000). The fact that the record of the eruption is found in both poles in the same year (based on the ice chronology) means that the eruption was likely in the tropics as well. So, based on these proxy records (i.e., indirect evidence for the eruption), we can safely say that the tropical eruption was likely during 1258 A.D. – and the missing eruption produced pronounced global temperature anomaly associated with it (see below).

Several days ago, Klemetti noted that a likely suspect for the 1258 eruption has been identified and, no great surprise, it was in Indonesia:

... [T]he eruption was from the modern Rinjani area, but the evidence points to an ancestral volcano that Lavigne and others calls Samalas (much like Mazama precedes Crater Lake), part of Rinjani volcanic complex on Lombok (see right). The current active cone of the modern Rinjani complex is Barujari cone within the caldera, a small cinder cone within the Segara Anak caldera. Lavigne and others point to an eruption from Samalas, a volcano that would sit where the modern 6.5 by 8 kilometer caldera (see above) is now as the source of the large sulfate spike, weather phenomena in 1257-59 A.D and the caldera itself.
... Levigne and others estimate that the eruption produced a 20-30 km eruption plume that lasted a little less than a day, and within that day, 4-6 hours worth of an ultraplinian phase with a plume topped 40 km. It moves the eruption into the same class as that massive ultraplinian eruption at Taupo in 186 A.D. Pyroclastic flow deposits from this eruption can be traced for tens of kilometers from the vent and even at 25 km distance, they are as thick as 35 meters. All in all, this was an eruption the likes of which we have not seen since the Katmai eruption in Alaska in 1912 (yes, even dwarfing Pinatubo in 1991).
... The 1257 A.D. eruption has been linked to mass burials in London, the ease which kings conquered the region in Indonesia not long after the eruption, and even potentially a buried capital city. ...