THE island volcano Krakatau in the Sunday strait between Sumatra and Java in Indonesia erupted in 1883, one of the largest in history. Over 35,000 people were killed and 16 coastal villages were destroyed. Krakatau remained active after the eruption, its vent forming a small island that was named Anak Krakatau, meaning child of Krakatau.
Last Saturday, Anak Krakatau erupted, sending a wall of water two meters high – a tsunami – racing to neighboring Java and Sumatra. Over 429 people were killed by the tsunami in islands around the strait. Earthquake geologists said the tsunami may have been caused by the collapse of the slope of the volcano.
Earlier, last September, in this same part of the globe, more than 2,500 people were killed in a quake and tsunami at an island of Sulawesi east of Borneo. In 2004, a massive 9.2 earthquake hit Sumatra, spawning a giant tsunami that killed more than 230,000 in several surrounding countries. The next year, 2005, an 8.5 quake again hit west Sumatra, killing 915.
All these eruptions are a cause of great concern to us in the Philippines, some 1,500 miles to the northeast of Sumatra. We are all part of what has been called the Pacific Ring of Fire, which has 452 volcanos; these constitute over 75 percent of the world’s volcanos. This Ring of Fire generates 90 percent of all of the world’s earthquakes. It extends from Japan in the Northwest Pacific, down to the Philippines, east to the many Indonesian islands, the South Pacific islands, to New Zealand, then north to the western nations of South and Central America, to western United States, to Alaska in the Northeast Pacific.
In this Ring of Fire is our Mount Pinatubo in Zambales which erupted in 1991, the second largest eruption in the 20th century after the Novarupta Earthquake in Alaska in 1912. We have not had a major volcanic eruption since , Pinatubo, but scientists warn that any of our many volcanos – Mayon, Taal, Kanlaon, Bulusan, Hibok-Hibok, etc – could erupt at any time.
Earthquakes could also strike at any time. As a matter of fact, we have long been holding annual exercises in expectation of the “Big One” anywhere along the West Fault from Nueva Ecija through Metro Manila to Cavite.
Scientists have warned against more earthquakes in the Sunda Strait area now that the Anak Krakatau volcano has been destabilized. The warning may well extend to us in the Philippines. We have long feared a major earthquake of magnitude 7.1 and it could be triggered by any disturbance along the rifts separating the land masses grinding against each other beneath the surface of our earth.
