Tracking Down Hurricanes' Fingerprints in Trees and Stone
by Jeremy Elton Jacquot, Los Angeles on 08.16.07
Stalagmites and trees probably aren't the first places you'd think to look for records of past hurricanes. But that's exactly what Amy Frappier, a geochemist at Boston College, and her colleagues have been doing for the past few years — investigating the stalagmite formations' growth layers for chemical fingerprints left behind by storms — and are now doing in the caves on Mexico's Yucatan peninsula.
At the same time, a team of researchers from the University of Tennessee has been searching for the same tell-tale fingerprints in tree rings — in samples gathered from a region of woods in Georgia. The trees have provided them with a record of hurricane activity stretching back almost 220 years.
All these recent efforts have focused on bringing to light the likelihood that storms will intensify as the climate continues to change. Because scientists agree that historical records obtained from aircraft and satellites fail to provide an adequate enough picture, there has been growing interest in the budding field of paleotempestology — the study of past tropical cyclone activity through geological proxies.
The Brazil-based Inter-American Institute for Global Change Research recently decided to fund a 6-year project to use this approach to study past cyclone activity in the entire Caribbean basin — an effort that will likely involve several dozen scientists from four different countries.
Though the specific approaches taken by researchers vary — some studying stone, trees or sediment cores from marshes and lakes — they all take advantage of shifts strong storms cause in the ratio of oxygen isotopes in the water they drop. Rain from these storms typically carries more of the lighter oxygen isotopes. In the case of tree-rings, scientists date lighter-colored portions as early-season growth while dating darker portions as late-season growth — with each segment undergoing an examination for the oxygen-isotope content. The techniques used to date stalagmites is similar. Scientists have been able to trace histories dating back 5,000 years using some of these methods.
"By putting together this team of people and tackling the problem from different angles using different techniques and looking at different time scales we will have a better understanding of the spatial and temporal variations in hurricane activity across the entire Caribbean Basin," said Kam-biu Liu, a paleoclimatologist at Louisiana State University who first applied this technique to study hurricanes in the late 1980s.
Via ::Christian Science Monitor: Clues from hurricane 'fingerprints' (newspaper)
See also: ::2006 Hurricane Forecast Exceeds Average, ::Hurricane Damages SOAR to New Levels, ::Recreating a Hurricane in Your Own Backyard
Image courtesy of GISuser.com via flickr
It will be interesting to hear what their findings are. After Katrina the environmental community went crazy with predictions. 2006 was forcasted as being possibly the worst hurricane season on record - certainly above average. Was it? Nope. 2007 was also predicted to be above average. Has it been so far? Nope. Since global warming is supposed to increase the number and strength of hurricanes, I'll be interested to see what comes of the reports. Since the level of global warming typically referenced has not been seen in pre-industrial times.
"After Katrina the environmental community went crazy with predictions. 2006 was forcasted as being possibly the worst hurricane season on record - certainly above average. Was it? Nope."
...ya know who also went crazy? The insurance industry. They stopped wrting coverage in the Gulf Coast. Now if you build down there, and another storm comes along, you risk pauperization.
And after a mere 1 1/2 hurricane seasons, THEY HAVEN'T CHANGED THEIR MINDS !
We environmentalists will be OVERJOYED if the sceintists are wrong about global warming. After all, the models predict serious economic and social upheaval if it occurs. However, we are obliged to weigh evidence, not hopes.
If you think climate change sceince is hype and fraud. then I think you wouldn't be commenting on Treehugger, you'd be down in Mississippi snappin' up some bargain land!