Even before the COVID-19 pandemic changed the daily lives of millions, the Philippines routinely faces natural calamities, it is one of the most disaster-pronce countries in the world with active volcanoes, earthquakes and an average of 20 typhoons every year.
Georgaphy is a factor. The country's eastern seaboard faces the warm waters of the Pacific Ocean where typhoons form. Many of these storms cut through the Philippines as they move northwest towards Hong Kong, Southern China and Japan. The most powerful and destructive storm in recent history, Yolanda (Haiyan) formed in the Pacific.
The Philippines is also on the so-called Pacific Ring of Fire, where continental plates meet, increasing the risk of earthquakes and volcanic eruptions. Unlike typhoons, scientists have yet to predict when earthquakes will strike. For volcanoes, a multi-tier warning system predicts the likelihood of an explosive eruption.
On Aug. 18, a strong earthquake struck the Central Philippines, cracking roads and tearing small houses to the ground in Masbate, one of the easternmost islands. Updates were also released on the status of several volcanoes, all at the lowest.
The disaster alerts tell those affected what is happening, what is expected and what can be done to avoid harm.
For volcanoes, PHIVOLCS tailor fits the alert to a specific volcano. Because of their locations, volcanoes pose different hazards. Remember how the Taal eruption in January blanketed Southern Luzon and Metro Manila in ash? For Mayon, a peculiar hazard is mudslides wherein heavy rains wash volcanic debris down its slopes, which can cause more damage than the ash eruption itself.
The agency also has an online resource on what to expect before an eruption and how to respond when it happens. Some are even written in the vernacular of the volcano's location. Access it here.
Weather bureau PAGASA recently updated its public storm warning signals to a scale of 1 to 5. These mainly predict wind speed and recently included expected wave height.
Be informed by following PAGASA's website. During typhoons, advisories are released thrice daily, at 5 a.m.
SIGNAL NO. 1
WINDS: 30-60 kph may be expected in at least 36 hr
SEA CONDITIONS (Open Sea)
Wave Height: 1.25-4.0 meters
DAMAGE TO STRUCTURE:
- Very light or no damage to high risk structures,
- Light to medium and low risk structures
- Slight damage to some houses of very light materials or makeshift structures in exposed communities.
DAMAGE TO VEGETATION:
- Some banana plants are tilted, a few downed and leaves are generally damaged
- Twigs of small trees may be broken.
- Rice crops, however, may suffer significant damage when it is in its flowering stage.
SIGNAL NO. 2
WINDS: 61-120 kph may be expected in at least 24 hr
SEA CONDITIONS (Open Sea)
Wave Height:4.1-14.0 m
Storm surge possible at coastal areas.
DAMAGE TO STRUCTURE:
- Light to Moderate damage to high risk structures;
- Very light to light damage to medium-risk structures;
- No damage to very light damage to low risk structures
- Unshielded, old dilapidated schoolhouses, makeshift shanties, and other structures of light materials are partially damaged or unroofed.
- Some old galvanized iron (G.I.) roofs may be peeled or blown off.
- Some wooden, old electric posts are tilted or downed.
- Some damage to poorly constructed signs/billboards.
DAMAGE TO VEGETATION:
- Most banana plants, a few mango trees, ipil-ipiland similar trees are downed or broken.
- Some coconut trees may be tilted with few others broken.
- Rice and corn may be adversely affected.
- Considerable damage to shrubbery and trees with some heavy-foliaged trees blown down.
SIGNAL NO. 3
WINDS: 121-170 kph may be expected in at least 18 hr
SEA CONDITIONS (Open Sea)
Wave Height: > 14.0 meters
Storm surge possible in coastal areas.
DAMAGE TO STRUCTURE:
- Heavy damage to high–risk structures;Moderate damage to medium-risk structures;
- Light damage to low-risk structures
- Increasing damage to old, dilapidated residential structures and houses of light materials (up to 50% in a community)
- Houses of medium strength materials (old, timber or mixed timber-CHB structures, usually with G.I. roofings), some warehouses or bodega-type structures are unroofed
DAMAGE TO VEGETATION:
- Almost all banana plants are downed, some big trees (acacia, mango, etc.) are broken or uprooted,
- Dwarf-type or hybrid coconut trees are tilted or downed
- Considerable damage to shrubbery and trees with heavy foliage blown off; some large trees blown down.
SIGNAL NO. 4
WINDS: 171-220 kph may be expected in at least 12 hr
SEA CONDITIONS (Open Sea)
Wave Height: more than 14.0 meters
Storm surge of 2 to 3 meters possible in coastal areas.
DAMAGE TO STRUCTURE:
- Very heavy damage to high –risk structures.
- Heavy damage to medium risk structures;
- Moderate damage to low-risk structures
- Considerable damage to structures of light materials (up to 75% are totally and partially destroyed); complete roof structure failures.
- Many houses of medium-built materials are unroofed, some with collapsed walls; extensive damage to doors and windows
- A few houses of first-class materials are partially damaged
- All signs/billboards are blown down.
DAMAGE TO VEGETATION:
- There is almost total damage to banana plantation,
- Most mango trees, ipil-ipiland similar types of large trees are downed or broken.
- Coconut plantation may suffer extensive damage.
- Rice and corn plantation may suffer severe losses.
SIGNAL NO. 5
WINDS: > 220 kph may be expected in at least 12 hr
A Super Typhoon will affect the locality.
SEA CONDITIONS (Open Sea)
Wave Height: more than 14.0 m
Storm surge more than 3 meters possible at coastal areas
DAMAGE TO STRUCTURE:
- Widespread damage to high-risk structures
- Very heavy damage to medium-risk structures
- Heavy damage to low-risk structures;
- Almost total damage to structures of light in highly exposed coastal areas.
- Complete roof failure on many residences and industrial buildings. Severe and extensive window and door damage
- Most residential and institutional buildings of mixed construction may be severely damaged.
- Electrical power distribution and communication services severely disrupted.
- All signs/billboards blown
DAMAGE TO VEGETATION:
- Total damage to banana plantation
- Most tall trees are broken, uprooted or defoliated;
- Coconut trees are stooped, broken or uprooted.
- Few plants and trees survived
Warnings are different for rains and thunderstorm, which can be issued whether or not there is a typhoon. Remember that some of the worst floodings in the capital, including the one from Ondoy (Ketsana) in 2009 were from weather systems that brought torrential rains without necessarily bringing strong winds.