Researchers from Australia conducted simulations and found that a healthy coral reef protects their country from tsunamis and other natural disasters. Climate change could cause Australia to lose its natural barrier.
The size and impact of the tsunami waves in the Pacific Ocean on the Australian coast has been significantly reduced due to the healthy coral structures on the Great Barrier Reef. However, new findings in Natural Hazards indicate that parts of the coast may now be at risk of increased tsunami damage as corals die, die, or lose their structural complexity.
Using simulation models, they were able to quantify for the first time that if the coral cover were completely removed, the amplitude of sea waves caused by a large-scale earthquake in the Solomon Islands would increase by 31%. “When we removed this coral blanket, the waves actually increased in size,” the scientists noted.
The team of researchers conducted various computer simulations of incidents that could actually cause a tsunami in the region, including earthquakes in the Solomon Islands, as well as landslides in and around the Great Barrier Reef itself.
For each simulation, the team first assumed that the coral cover was healthy, rough and complex. They then revised simulations for conditions in which the coral was considered smooth, such as after it had been damaged by climate change. Finally, they analyzed models in which the entire platform had been removed in order to assess the buffering capacity of the Great Barrier Reef itself.
In all cases, the key component was the coral “roughness” on the reef, which is maximized when the structure is healthy and has a living complex structure. As they approach the reef, tsunami waves bend inward, focusing energy on the platform and potentially causing waves to grow larger and stronger. However, when coarse coral structures are present on the reef, frictional forces are generated that counteract the effect and reduce waves.