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Wednesday, March 9, 2016
3/9/16 Report - Shipwrecks, Tree Rings and Hurricane Data.
Here are some excerpts from an interesting article from the University of Arizona News.
... Records of Spanish shipwrecks combined with tree-ring records show the period 1645 to 1715 had the fewest Caribbean hurricanes since 1500, according to new University of Arizona-led research. The study is the first to use shipwrecks as a proxy for hurricane activity...
The 1715 Fleet was just unlucky, I guess.
...The researchers found a 75 percent reduction in the number of Caribbean hurricanes from 1645-1715, a time with little sunspot activity and cool temperatures in the Northern Hemisphere.
Although global climate models indicate hurricanes will be more intense as the climate warms, those models are not yet good at making regional predictions, Trouet said. Learning more about how hurricanes correlated with climate for the past 500 years may lead to better regional predictions of hurricanes.
The new research provides an annual record of Caribbean hurricanes going back to the year 1500 — shortly after Christopher Columbus first reached the Caribbean.
Harley mentioned he had tree-ring records from the Florida Keys that went back to 1707 — and that the tree rings revealed when hurricanes had occurred. The growth of trees is retarded in years with hurricanes. That reduction in growth is reflected in the tree's annual rings.
Domínguez-Delmás, a dendroarchaelogist, figures out when Spanish ships were built by retrieving wood from shipwrecks and dating the wood. Trouet wondered whether the tree-ring record of Florida hurricanes could be combined with shipwreck data to create a long-term history of Caribbean hurricanes.
The books, combined with ship logs, allowed the researchers to compile a list of Spanish ships known to have been wrecked by storms during the hurricane seasons of 1495-1825. The team found that the hurricane patterns from the shipwreck database closely matched Florida Keys tree-ring chronology of hurricanes from 1707-1825.
In addition, the team compared the Florida Keys tree-ring records to the systematic recordings of hurricanes from 1850-2009. Again, the patterns matched.
When they overlapped the shipwreck data with the tree-ring data, the researchers discovered a 75 percent reduction in hurricane activity from 1645-1715, a time period known as the Maunder Minimum.
The Maunder Minimum is so named because there was a low in sunspot activity during that time. Here is the link if you want to read the entire article.