"We discovered that if you miss sampling these storms, then you miss truly understanding the sediment and chemical delivery of these rivers," said study coauthor and Ohio State doctoral student Steve Goldsmith.
The researchers found that, of the 61 million tons of sediment carried out to sea by the Choshui River during Typhoon Mindulle, some 500,000 tons consisted of particles of carbon created during chemical weathering. That's about 95 percent as much carbon as the river transports during normal rains over an entire year, and it equates to more than 400 tons of carbon being washed away for each square mile of the watershed during the storm.
Carey's collaborators from Academia Sinica -- a major research institute in Taiwan -- happened to be out collecting sediments for a long-term study of the region when Mindulle erupted in the Pacific.
"I don't want to say that a typhoon is serendipity, but you take what the weather provides," Carey said. "Since Taiwan has an average of four typhoons a year, in summer you pretty much can't avoid them. It's not unusual for some of us to be out in the field when one hits."
As the storm neared the coast, the geologists drove to the Choshui River watershed near the central western portion of the country.
Normally, the river is very shallow. But during a typhoon, it swells with water from the mountains. It's not unusual to see boulders the size of cars -- or actual cars -- floating downstream.
Mindulle gave the geologists their first chance to test some new equipment they designed for capturing water samples from storm runoff.
The equipment consisted of one-liter plastic bottles wedged inside a weighted Teflon case that would s
|Contact: Anne Carey|
Ohio State University