Burning Sea, The
In 1744 AD an asteroid impacted the Huangzu Wan devastating the Lower Yangtze and surrounding areas.
Seventy Miles from the mouth of the Yangtze River: Late in '44, the skies above the balmy and pacific coast of China split wide with a monstrous, unimaginable howl. The air convulsed, slammed aside by a quarter-mile wide rock, and rushed out from the oncoming beast at typhoon speeds. Vast dark banks of stormcloud raged with lightning, spilling away across the China Seas. A huge flaming mass punched into the ocean, catapulting out waves a mile high. Most of the water in the area of impact vaporized into a boiling cauldron of superheated steam. The asteroid sledgehammered into the ocean floor, sending a shockwave through the muddy bottom of the shallow sea.
Within hours, the atmospheric shockwave crashed across the Chinese coast, shattering buildings, flattening temples, tearing trees up by the roots, whirling thousands of people away into the sky. A wall of superheated steam followed, parboiling or incinerating everything exposed to the air. Cities and towns burst into flame. Two hours later, the burning cities of Lin'an, Shanghai and Fuzhou vanished under a vast tidal wave which came roaring up out of the deeps like the doom of god.
Multiple aftershocks rippled out across the sea floor, causing waterspouts and whirlpools to consume shipping. The huge wave thrown out - which had annihilated the provinces of Kiangsu, Taiping, Chekiang and Fukien - was still a hundred feet high when it slammed into Cheju-do, northern Taiwan and Okinawa. Tens of thousands more perished, and there was heavy damage to all the cities facing the Huang Hai and the Tsushima Strait.
The plume of steam (and vaporized fish and dust and rock) thrown up from the impact mounted into the heavens, eventually spreading out into a vast black pall across northern Asia. A dense cloud, impenetrable to the sun...
(2) Hum deed um... ok, rolling for a spotting round. Hm, only one round, so I guess they're firing for effect. Roll... scatters off ground zero (Ise) to the... roll... southwest... roll... four zones and into the Huangzhu Wan. Shoot. That's messy. Better email Briana about this... (later) ok, one asteroid into the drink!
(3) Luckily for everyone in Japan and on Taiwan, the impact did not strike the China Sea fault line.
(4) In addition to everything just being smashed down, incinerated and washed away. Everything was drenched in seawater and brine from the depths of the sea, which is just not good for the local agriculture.
(5) Is Tom being nice? Yes, he is. Check out this page:  for a depiction of a cometary impact off New York. In this case, I'm saying the amount of kinetic energy injected into the sea and atmosphere is much lower as the asteroid the mi-go dropped was not moving when they tipped it into the atmosphere, so it did not have a lot of momentum. Still wouldn't want one dropped on me...
Tokugawa Japan: The year 1744, however, was one of calamity and woe. Those surviving accounts name it, the year of the Burning Wind, for great typhoons roared up out of the south-west, lashing the islands not with chilling rain, but smoking steam and terrible heat. Fires broke out in every city, causing widespread destruction and loss of life. The crops failed - the rice cooked in the paddies - and even in Holy Ise there was great mourning.
PM&T: Luzon took a heavy blow from the tidal waves and burning rain flung down by Jehanantukul (Hell's Hammer), but the port of Kryztin was spared much of the destruction by the high mountain ranges across northern Luzon.
Pure Realm: Cho Hun remained in the south, attempting to restore some order to the wreckage of the Realm's temples and farms there. Only by good luck did he escape death during the "rain of fire" and the dreadful killing fogs which followed. All reports from the north were worse, and he despaired of seeing Fusan again - for the seas had turned strange and travel by boat was impossible.
Mongol Empire: Substantial efforts were also made to return the Iced land to cultivation, which was wise for the shockingly huge storms of '44 wrecked most of the coastal settlements in Koguryo, Anshan and Bandao. The 'black sky' reported by Japanese merchants also afflicted the Manchu, and the failure of the late harvest in '44 boded ill for everyone.
Judah: Still displeased with the way the Ming were making a mess of the war in Annam, Yui-Yen considered dispatching a few Yaqui rifle regiments to clean things up... but then changed his mind. There were more pressing matters at home. Indeed, he'd started to get a queer feeling of impending trouble. Acting on the intuition which had saved him more than once, the Hand ordered massive stockpiles of food, firewood, coal and animal feed be gathered in every city and town. His provincial police were put on alert, and he gathered his armies to him in Pienching, waiting for Something to happen.
Then, of course, the southeastern sky rippled with flame, and a vast crashing boom rolled across the land. Old Yui-Yen rose from his gilded chair, blind eyes turned to the sky, and he snarled in disgust. "Foul carrion," he muttered - and one of his courtiers, cowering nearby, heard him - "digging worms, crawling before His black feet, licking His hands. Well, I know their fate - and they will rue this day..."
A rushing wind howled across the land, and everyone looked up in fear. Yui-Yen gathered up his little boys and bade their nurses take them into the deepest cellar of the palace. The Hand, himself, betook himself to the armories and girded blade, pistol and rifle to his hand. Within the hour, the winds had risen to a gale and the entire city shook and moaned with force of the hellstorm roaring out of the south.
Thanks to the Hands' foresight, though there was great destruction in the south, the army and the police were ready to help and aid as they could. No one, at least, would go hungry this year. Admiral Falcon - who had suffered such plights - was killed when the tidal wave hit Nantong, and the last of the Judean fleet was torn to shreds. General Wui also perished in the south, vanishing with so many others whose bodies were never even recovered.
Ming Empire: Though Yongzheng had long railed and ranted against the Annamese, his presence (and that of the entire Ming army) in the south saved them from the horrific destruction visited upon the Ming coast around the mouth of the Yangtze - and even Wuhan suffered from the terrible burning winds. Only by great luck did the hapless Emperor Hongzhi (who had run outside to see what was happening) survive a great fire in the city, as well as vicious tornadoes and cyclone winds.
Hosogawa: Though the shogunate suffered from terrible storms in the north, and the same darkening sky afflicting other Asian nations, the immediate damage from the Hell Hammer was limited to Luzon, where the port at Kryztin suffered fires and many ships were destroyed.
Ming Empire: The disastrous spread of the plague in the south did not stop one critical project, however, which was a massive dredging project along the lower Yangtze. Under the direction of the generals Wang Lung and Wang-Li-Chung, nearly forty-six thousand workers (supervised by the Imperial Engineering Corps) slaved throughout ’45 and ’46 to clear the channel of the river. This proved a monstrous undertaking (not only had the Hell Hammer wrecked Taiping province, but it had blocked the river, making an enormous bog out of western Taiping and southern Anhui province) and fraught with danger.
Deadly fumes boiled from the earth, vast mires of quicksand swallowed men and equipment, ghostly voices drove the workers mad, the sky rained ash constantly, those weak of lung perished from the choking air and oft times the work parties were attacked by insects, worms and beetles of unusual size. Wang Lung’s troopers earned a name for singular bravery by patrolling the forward edge of the excavations, driving off cannibals, bandits and other, less savory things.
Still, despite all this, the work was not yet done at the end of ’46, though the vast lake was beginning to drain.