Fauzy Chaniago / AP
A submarine earthquake occurred Saturday off the coast of the southern Philippines. The US Geological Survey says it hit at a depth of about 38 miles and a magnitude of 7.0. According to The Associated Press, a few hours after the quake, no accidents or damage were reported. However, in several cities in the southern Philippines, it felt it caused a tsunami threat from the Pacific Tsunami Warning Center – which has since been lifted – for areas along the coasts of Indonesia and the Philippines.
This is the latest fear that has done seemingly little damage is the recent seismic activity in a region ravaging disaster. On December 22, a tsunami hit Indonesia, killing at least 430 people. Anthony Kuhn of NPR reported that the Indonesian directors were flawed for seismic activity, meaning that residents were not properly warned about the upcoming event. Kuhn also pointed out that before the tsunami, the Indonesians did not feel an earthquake, a common warning sign. A widespread video of a concert is one of the more disturbing illustrations of how unexpected the catastrophe was: local pop-rock band Seventeen performed for a moment at a party in Java and was soon followed by a massive wave.
Scientists may now know why the catastrophe happened last Saturday. According to a statement by the European Geoscientific Union, the partial collapse of Anak Krakatau, a volcano in the Sunda Strait in Indonesia, may have caused the tsunami. Researcher Raphaël Paris says the instability of Anak Krakatau will continue to pose a risk. In the EGU statement, Paris says: "The stability of the volcanic cone is now very uncertain, and the likelihood of future collapses and tsunamis may not be insignificant."
When Anak Krakatau lost a 64-acre tract of land to his west-southwest flank, tons of debris fell into the sea, causing strong waves. According to Jonathan Amos of the BBC, this could have been the source. NPR's Julie McCarthy reports that scientists say the volcanic cone has declined from 1,108 feet to 336 feet (336 feet). Satellite images also show a significant decline in the size of Anak Krakatau.
Geospatial Information Authority of Japan on AP
Paris was part of a team that modeled a very similar Anak Krakatau-induced tsunami in 2012. Mike Burton, president of the EGU's Department of Geochemistry, Mineralogy, Petrology and Volcanology, said in the EGU statement, "The danger scenario was understood, but tackling such a threat obviously remains a major challenge."
The cause of the tsunami – the type of eruption that triggered, for example, the loss of the flank – is only discovered by researchers who can access the area of the volcano, according to Amos of the BBC.
Anak Krakatau translates as "Child of Krakatoa". Anak's parent, Krakatau (or Krakatoa), is perhaps best known for his explosion in 1883. According to Neal Conan of Hawaii Public Radio, about 100,000 people died as a direct result of this outbreak, and more than 35,000 died from tsunami waves. Anak Krakatau was formed from the rest of Krakatau after this massive event.
Less than three months ago, another tsunami in Indonesia killed at least 1,400 more people. In August, a magnitude 6.9 earthquake killed at least 460 people. According to a statement released in October by the National Agency for Disaster Management (BNPB) in Indonesia, there were 1,999 natural disasters in Indonesia in 2018 3,548.