Coral reefs help protect from tsunami damage
Coral reefs help protect from tsunami damage
mongabay.com
December 18, 2006
Healthy coral reefs can help reduce the impact of tsunami waves relative to unhealthy or dead reefs, according to a new Princeton University study published in the December 14 edition of the journal Geophysical Review Letters.
Using a computer to model a tsunami strike against a reef-bounded shoreline, the research indicates that “healthy reefs offer the coast at least twice as much protection as dead reefs.”
“Healthy reefs have rougher surfaces, which provide friction that slows the waves substantially in comparison with smoother, unhealthy ones,” said Michael Oppenheimer, a Professor of Geosciences and International Affairs. “Scientists had never before studied this effect by the numbers, nor had they ever analyzed it over a wide variety of coastal shapes. This study provides yet another motivating factor for protecting the planet’s coral reefs from degradation.”
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The research supports anecdotal evidence that suggested the tsunami-buffering capabilities of coral reefs.
“For our purposes, we assumed that the health of the reef would only be important in terms of the drag it exerted on the wave,” said Catherine Kunkel, who is the paper’s lead author and is currently working as a research assistant at Tsinghua University in China. “If you have a healthy reef, it has lots of live coral branching out, sticking a lot of small obstacles into the water. A dead reef, on the other hand, is not as rough — it tends to erode and exerts less drag on the wave.”
“The general conclusion is that a healthy reef might provide twice as much protection as a dead one,” Oppenheimer said. “This could translate into sparing large sections of inshore area from destruction.”
Given ongoing decline of coral reefs due to human disturbance and climate change — warmer sea temperatures and increasing ocean acidity due to higher concentrations of dissolved carbon dioxide are causing coral bleaching and death — Oppenheimer argues that the study offers “yet another reason to protect these fragile offshore ecosystems.”
“This study shows yet another way that protecting the environment relates to humanity in a very tangible way,” he said. “Villages get built behind coral reefs for good reasons, and this is one of them.”
This article is based on a press release from Princeton University. The paper, “Coral reefs reduce tsunami impact in model simulations” is written by Catherine M. Kunkel, Robert W. Hallberg, and Michael Oppenheimer. It appears in the Dec. 14 edition of the journal Geophysical Review Letters.
