Hurricanes return to historic patterns

NEW YORK, June 6 (UPI) -- A study by U.S. and Swedish researchers says the surge in major Atlantic hurricanes may not be tied to increasing global warming.

The report, published in the journal Nature, says the storm surge may be a return to normal storm patterns. The researchers say major hurricanes were nearly as frequent from the mid-1700s to the mid-1900s, the Los Angeles Times said Wednesday.

Study co-author Terrence Quinn, a paleoclimatologist at the University of Texas at Austin, said the number of major hurricanes from the late 1960s to the early 1990s was unusually light.

The researchers, who studied long cylinders of coral from reefs in the Caribbean, found that from 1730 there was an average each year of 3-3.5 major hurricanes. By the late 1960s, the frequency had fallen to 1.5 major hurricanes a year. The average between 1995 and 2005 jumped to 4.1 a year.

The report said vertical wind shear may have caused the reduction of hurricanes. When wind shear is high, it is more difficult for hurricanes to form and gain strength, the report said.