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Typhoon Talas, a storm that swept across Japan over the weekend, has taken a terrible toll; the storm and its lingering effects have so far killed 47 people, with 54 still missing. Much of the death and destruction is concentrated in three provinces in the nation's southwest.
So how did the storm, as some news outlets have reported, become the deadliest in seven years for the country? Several factors, some on the ground, and some in the sky, conspired to lend the deadly force to the typhoon — the term for hurricanes in the Pacific Ocean, according to meteorologists.
Much of the devastation in Japan is the result of record-breaking rains, which caused deadly floods and landslides. [Top 10 Deadliest Natural Disasters in History]
'Insane amount of rain'
Talas was a massive storm, and took its time moving across the island, said Rob Gutro, a meteorologist and manager of NASA's hurricane page, two of the reasons parts of Japan were lashed with so much rain.
"If you've got a 420-mile-wide [675 kilometers] storm, and it's moving at 11 mph [18 kph], which is on the slow edge of speed for a tropical storm, it's going to take a long time to get across that island," Gutro said.
In one area, Talas dropped 65 inches (165 centimeters) of rain in 72 hours, a new record for the country, according to the Japan Meteorological Agency.
"That's an insane amount of rain," said Stephen Lang, a research meteorologist with research firm SSAI and NASA's Goddard Space Flight Center in Greenbelt, Md.
Even though the storm was huge when it made landfall in Japan, it had weakened somewhat, but even weak storms can drop a lot of rain, Lang said.
"The correlation between rainfall and the intensity of the storm isn't that great," he said, "it's how fast a storm is moving. So you could have a weaker tropical storm drop a whole lot more rain than an intense hurricane if the hurricane is moving more quickly."
Mountains and mudslides
In addition, the mountainous topography of the area that was worst affected may have further exacerbated bad conditions for the people living there.
When tropical storms pass over mountainous terrain, they typically produce more rain, said Robert Adler, an atmospheric scientist at the University of Maryland.
"If the air is going upslope, you get even more rain than if it were going over flat ground," Adler told OurAmazingPlanet. "And then going over a slope, that increased amount of rainfall has an even higher probability of producing a landslide," he said.
In addition to the way terrain may have magnified the storm's tragic effects, Gutro said Japan appears to have lain directly in the path of Talas' wettest region.
"The area that had the heaviest rainfall was the entire northern quadrant of the storm, which is what ran aground on Japan," Gutro said. This was the same storm area that soaked many of the Mid-Atlantic and New England states when Hurricane Irene moved through the area a little more than a week ago.
© Reprinted with permission of OurAmazingPlanet
5 Comments
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Carcharodon
one more parameter to factor in, which further exacerbated the problems. The huge sugi (cedar tree) planting program on these hills of the Kii Peninsula, post WWII to fuel the reconstruction, As well as contributing to a horrendous pollen problem each March, these trees are now fully mature and have never been harvested; because its not economically viable to do so. So you have millions of cedar trees jammed onto steep slopes and the problem is the cedar trees are heavy and have poor roots that don't go deep and do not bind that mountain side together well. They add to the problem - not help it. Too much rain --->saturated soil ----> thousands of tonnes of sugi deadweight - that means a landslide is more likely to occur. With the huge amount of precipitation that Talas brought it was a recipe for disaster.
ironchef
good point Carcharodon. those politicians back then were really brilliant in overplanting those sugi trees, weren't they?
nath
@Carcharodon: I think you are mistaken about them being shallow rooted.
Lunchbox
Carcharodon,
Yes, the cedar platings are a big contributor to the flash floods. More than the depth of the roots, the problem is that the cedar trees suck all the water out of the ground allowing nothing else to grow, over 30-40 years the top soil recieves no compost because the cedar trees don't shed their leaves, and the ground becomes hard as concrete. So the rain just runs straight off instead of soaking into the ground. In heavy rainfalls, the run-off goes straight down to the rivers, and bang, we get flooding.
But, all that said, 165cm in 72 hours is a lot of rain!
NeoNOMAD_KYRGYZ
Why this Typhoon was named TALAS ?
In our country we have a town named Talas - KYRGYZ Republic -Central Asia!
Is it a japanese word ?
Here is a Kyrgyz map: http://image.torrent.kg/images/aQM6563.gif