A precise method of analyzing cyclone activities reveals that the shells of giant clams are capable of recording environment data including that of storms.
Experts believe that the planet will experience more tropical cyclones as climate change continues to be a major environmental issue. To better predict weather patterns, it is important to analyze past records of the Earth's warmer periods.
Giant Clam Shells And The Environment
A team of scientists led by Tsuyoshi Watanabe of Hokkaido University reported that the microstructure and chemical composition of giant clam shells can help them understand cyclone behaviors.
They chose to study the giant clam Tridacna maxima due to the fast and precise growth rate of its shell. The clams have increments on their shells, similar to tree rings, which give scientists an idea of their environment.
"Since microstructural and geochemical features are well preserved in giant clam fossils, it may now be possible to reconstruct the timing and occurrence of past typhoons to a level of accuracy that was previously impossible," said Watanabe.
Details of the study are available in the Journal of Geophysical Research: Biogeosciences.
How Does Climate Affect The Clam Shells
Live samples of T. maxima were collected from the waters of Okinotori Island, where past typhoons made a landfall in the said area of Japan. Watanabe's team analyzed the shell's growth increment per year by measuring its thickness, stable isotope ratio, and barium or calcium ratio.
The data are then compared to past records of typhoons and water temperatures. As water temperatures drop, the barium or calcium ratio and the stable isotope ratio on the clam shells change.
The researchers noted that clams that live longer than other species may provide data to fill in gaps at the start of the 20th century. Fossilized clams are also likely to contain traces of chemical compositions that could reveal storm patterns back in time.
Validating Study Results
Matthew Peros, an associate professor in the department of environment and geography in Bishop's University in Canada, said that experts used stalagmites, tree rings, and microfossils to study tropical cyclones.
Hali Kilbourne, an associate professor at the University of Maryland, said the results of the study cannot be predictive of storms.
"If I were to look at the data and try to pick out the storms, I'm not 100% sure I could do so if I didn't already know when the storms existed," Kilbourne said in an interview. "I think that's a problem for actually using something like this. For me, that means that we're just not there yet, there's more work to be done."
