By Catherine Teves
An expert is urging the public to take notice of nature's warnings about a looming onslaught of tsunami, the series of sea waves that underwater or offshore earthquakes generate.
Ground shaking due to tsunami-generating earthquake's occurrence, sudden and unusual drop in sea level as well as louder-than-usual sound of roaring or rumbling waters are nature's warnings that a tsunami is about to hit land, noted Philippine Institute of Volcanology and Seismology (Phivolcs) science research assistant Leniel Villalobos.
"People must learn to recognize such signs and run to high ground when they observe these," she said in a recent interview. People must act as fast as they can since historical records show it takes an average of only two to five minutes for a local tsunami to landfall after the occurrence of an earthquake.
"The natural shake, drop and roar signs of a tsunami onslaught occur within those minutes," she noted, citing the period when people have the opportunity to seek safer ground and possibly save themselves.
In December 2015, the UN General Assembly designated Nov. 5 as World Tsunami Awareness Day (WTAD) -- an annual occasion for promoting greater understanding of tsunami risk to help minimize and even avoid future loss of life.
Phivolcs is holding a forum and exhibit in Parañaque City Nov. 5-6, to spearhead the country's 2018 observance of WTAD aimed at promoting tsunami awareness as well as disaster risk reduction and management.
Phivolcs said the Philippines is vulnerable to tsunamis, having earthquake generators like the Manila Trench, Negros Trench, Sulu Trench, Cotabato Trench, Philippine Trench and East Luzon Trough.
"All coastal communities facing seas surrounding the country are at risk for tsunamis," Villalobos noted.
She said offshore earthquakes of magnitude 6.5 or stronger, and occurring at a maximum depth of 100 km, can generate tsunamis.
Villalobos urged people, particularly those in coastal communities nationwide, to monitor and heed Phivolcs' tsunami advisories.
"It's also still important to learn what nature's warning signs are so people can run to safer ground even if they can't receive our advisories," she clarified.
Technical problems may make it difficult to transmit Phivolcs' tsunami advisories through the Web and media, Villalobos noted.
According to Phivolcs, 38 people drowned due to a tsunami from a magnitude 7.1 earthquake that struck Mindoro on Nov. 15, 1994.
A magnitude 8.1 earthquake on Aug. 17, 1976 due to movement along Cotabato Trench produced a tsunami that killed about 6,000 people - making this the country's most disastrous tsunami so far, Phivolcs continued.
Phivolcs OIC and DOST Undersecretary Dr. Renato Solidum Jr. also said there's historical evidence of tsunami in Metro Manila.
"It's important that we learn from past experiences so we know how we can prepare in case it happens again in the future," he said in Phivolcs' Oct. 29, 2018 press release.
The 2018 WTAD focused on Sendai Framework for Disaster Risk Reduction's third target which is reducing direct disaster-related economic losses in relation to global GDP by 2030.
Reducing such economic losses is vital to eradicating extreme poverty worldwide, UN Secretary-General Antonio Guterres said earlier in his message for this year's WTAD.
"Over the past two decades, tsunamis have accounted for almost 10 percent of economic losses from disasters, setting back development gains especially in countries that border the Indian and Pacific Oceans," he said further.
Guterres highlighted the importance of early warning, information, science as well as disaster prevention and preparedness in promoting public understanding and prediction of tsunamis.
UN General Assembly tasked UN Office for Disaster Risk Reduction with coordinating activities for observing WTAD.
Choice of date for the annual WTAD was in honor of the Japanese story of "Inamura-no-hi" which means "burning of the rice sheaves".
"During a 1854 earthquake, a farmer saw the tide receding, a sign of a looming tsunami," UN said. "He set fire to his entire harvest to warn villagers who fled to high ground. Afterwards, he built an embankment and planted trees as a buffer against future waves."