- March 31st, 2009
- in Yachting
In the Caribbean Sea – In February, a team from the United States Geological Survey studied the over-wash of Anegada’s north shore beaches to determine if tsunamis are a potential threat at sites of proposed nuclear power plants on the U.S. Atlantic Coast, according to a news release from the BVI Department of Disaster Management. Whether or not they are a cause of the over-wash, tsunamis have hit the Caribbean in the past.
According to a 2007 National Geographic News article, 37 known tsunamis have struck the Caribbean since 1498, resulting in a total of approximately 9500 deaths. While the Caribbean waits for an official warning system, slated to be in effect by 2010, there are also several natural warning signs and safety tips for those on land and sea.
The Caribbean Detection System
According to Lorna Inniss, Ph.D., Deputy Director of the Coastal Zone Management Unit in Barbados, a real-time monitoring and detection system is crucial. “So,” she says, “we are developing a seismic and a sea-level network, using instruments within the region that meet the standards of the system.” Dr. Inniss also stresses the importance of communication in the case of a tsunami, “not just from the warning center to the countries but from the national warning focal points to vulnerable communities.” This small-scale communication is the responsibility of individual countries to “determine their own communications protocols that will be followed in the event of such a rapid onset event.”
The Global Telecommunications System of the World Meteorological Organization is the system to be implemented. Dr. Inniss informs us that “more than 90% of our Caribbean countries have this system in place, and all have access to information from this system.” On March 16, the fourth session of the Intergovernmental Coordination Group is being held in Martinique to determine some of the final details concerning the Caribbean Tsunami Information Center which is currently being hosted by Barbados.
Natural Warning Signs
Even if a proper warning communications and detection system is in place, it is also important to be aware of the natural warning signs.
One common warning sign is an earthquake—not the little tremors that we’ve felt in the BVI over the past few months, though. The earthquake has to be strong enough that you have a difficult time standing up. If you feel an earthquake of that magnitude, relocate to higher ground and stay there for several hours. Waves can take hours to reach the shore after an earthquake. Additionally, tsunamis are not a single wave, but a series of waves, so you are not in the clear after the first wave has retreated. In the Indian Ocean tsunami of 2004, it was the third wave that caused the most damage, and smaller tsunami waves continued to hit the shores for the remainder of the day.
If water retreats so far away that you can see the sea floor, run to higher ground immediately. This is a common sign of a tsunami, but according to the National Geographic article, “a receding ocean may give people as much as five minutes’ warning to evacuate the area.” Unfortunately, during the 2004 Indian Ocean tsunami, this phenomenon caused many children in Sri Lanka to investigate the exposed ocean floor. Melissa Block on NPR’s All Thing Considered reported that “the waters had pulled back and a number of fish had landed on the beach, and kids had gone down to collect the fish and that may explain partly at least why the death toll among children is so high.” But knowledge of this warning sign also saved lives in Thailand where some beaches were evacuated before the tsunami roared to shore, thanks to a biology teacher from Scotland who warned tourists and locals at one beach and a 10-year old British student who had just studied tsunamis in geology class who pointed out the signs at another beach.
Tsunamis do sometimes actually roar. Of the 2006 tsunami in Indonesia, The Age newspaper reported survivors claiming to hear a roar like a jumbo jet, a waterfall, and “a stampede of buffaloes.” Others have reported it to sounding like a freight train.
If any of these signs occur, ascend to higher ground and contact others who you feel may be in danger to do the same.
While people on the shore are advised to seek higher ground, the United States National Oceanic and Atmospheric Administration (NOAA) recommends that sailors head for deeper waters, at least 100 fathoms, where tsunami waves are smaller. If a tsunami warning has been issued, do not return to harbour. The waves are often imperceptible at open sea while port facilities may be unsafe. Do not return to harbour until you are certain that conditions are safe. Remember—this could be several hours after the first warning signs.
Additionally, locations surrounding streams and rivers feeding into the sea should be avoided because the water can surge in these areas as well.
Dr. Inniss asserts that “the requirement for public education and awareness cannot be stressed enough.” Educate yourself and others about the tsunami warning signs and procedures. The US Geological Survey may find another cause for the over-wash, but their presence reminds us that all coastal areas are vulnerable to tsunami activity.