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Messenger birds and poisonous exhalations
Sep. 24th, 2014 08:22 amOn September 21–22 in Pen Pal, Kaya first started using her crow Sumi to carry messages. Although crows are messenger birds in many mythologies, they're not actually used as couriers in real life, not regularly anyway--pigeons are. People all over the world enjoy keeping homing pigeons (including in my town: I got a tour of a dovecote some years back--picture here); pigeons were used to deliver mail in India into the 2000s; and China still keeps military homing pigeons as a safeguard in the event that twenty-first-century communications are disabled for some reason (see Malcolm Moore, "China Trains Army of Messenger Pigeons," Telegraph, March 2, 2011.)
(Image source: Morgan Banaszek, "12 Facts about China You Probably Didn't Know,", Project Pengyou.)
On September 28 in Pen Pal, a bubble of carbon dioxide rises from a lake in Kaya's country, with disastrous consequences. In real life, this happened most dramatically in Cameroon's Lake Nyos in 1986. Lake Nyos is a crater lake, into which carbon dioxide slowly seeps from a pocket of magma. On August 21, the weight of water on top of the accumulating carbon dioxide was no longer enough to keep it down: it bubbled up and out, and because carbon dioxide is heavier than air, it settled on the surrounding land, suffocating approximately 1,700 people and 3,500 livestock. A similar, less devastating event had occurred two years earlier at another lake in Cameroon, Lake Monoun. The only other lake known to be at risk of this is in the Democratic Republic of the Congo, but all that's required for it to be possible is a lake above a volcanic fissure.
The eruption of carbon dioxide at Lake Nyos was accompanied by a rise in dissolved iron to the lake's surface, turning it rusty red:
[image no longer available]
Accumulations of carbon dioxide in mines are one of four sorts of killing "damps" (from the German dampf, meaning "vapor"--they're "choke damp" (also called "stythe damp"). The other sorts are "white damp" (carbon monoxide), "fire damp" (methane or other flammable gasses), and "stink damp" (hydrogen sulfide).
(Image source: Morgan Banaszek, "12 Facts about China You Probably Didn't Know,", Project Pengyou.)
On September 28 in Pen Pal, a bubble of carbon dioxide rises from a lake in Kaya's country, with disastrous consequences. In real life, this happened most dramatically in Cameroon's Lake Nyos in 1986. Lake Nyos is a crater lake, into which carbon dioxide slowly seeps from a pocket of magma. On August 21, the weight of water on top of the accumulating carbon dioxide was no longer enough to keep it down: it bubbled up and out, and because carbon dioxide is heavier than air, it settled on the surrounding land, suffocating approximately 1,700 people and 3,500 livestock. A similar, less devastating event had occurred two years earlier at another lake in Cameroon, Lake Monoun. The only other lake known to be at risk of this is in the Democratic Republic of the Congo, but all that's required for it to be possible is a lake above a volcanic fissure.
The eruption of carbon dioxide at Lake Nyos was accompanied by a rise in dissolved iron to the lake's surface, turning it rusty red:
[image no longer available]
Accumulations of carbon dioxide in mines are one of four sorts of killing "damps" (from the German dampf, meaning "vapor"--they're "choke damp" (also called "stythe damp"). The other sorts are "white damp" (carbon monoxide), "fire damp" (methane or other flammable gasses), and "stink damp" (hydrogen sulfide).
