According to the Chosun Ilbo, nothing good.

Mind you, it’s always a possibility—according to the Smithsonian, it’s erupted 10 times in the last 4,000 years, and 1,000 years ago, it experienced an eruption so massive it left a 5—6cm layer of ash all the way in Hokkaido. It most recently erupted in 1903. Chinese researchers have confirmed three magma chambers underneath Cheonji Lake, the pretty crater lake you see in all the photos.

A simulation by the National Institute of Meteorological Research showed that ash would reach South Korea if Baekdusan erupted continuously for four days AND Korea was experiencing a “west high east low type” pressure system over the center of the peninsula. Should the cloud of the explosion climb to over 25km high, we could be looking at an ash concentration 1,000 times the level that would set off a hwangsa alert in spring.

That would suck serious balls, especially if you lived in Gangwon-do or Gyeonggi-do, where much of the ash would get dumped. To make matters worse, if volcanic ash shut down flights for 10 days, it would reduce exports by US$2.5 billion.

A major eruption would screw a lot of other stuff up, too—crops would be hurt by plummeting temperatures, dust would screw with the semiconductor and shipbuilding industries, tourism and retail would be hurt, and you’d see a bump in respiratory illnesses.

Marmot’s Note: Are there historical records for the eruption in the 940s that blew off the top of the mountain to create the caldera we all know and love today? You’d have to think somebody would have noticed something like that. I could scour the Internet myself, but I’m feeling a tad lazy today.

BTW, I’ve actually been to Baekdusan—back in 2000. It was quite lovely, but I’d have enjoyed it more if I wasn’t dreadfully hung-over that morning. I’d be rather keen to go up again this year to get a decent photograph of the lake.