Philippines earthquake activity intensified today as a powerful magnitude 7.8 tremor struck in the Celebes Sea near Sarangani Island, followed by dozens of smaller shocks across the region.
The strongest quake had a shallow depth of 55 km and occurred about four hours before the most recent recordings, and it was felt over a wide area.
In the past 24 hours the region recorded one magnitude 7.8 event, three quakes between 6.0 and 7.0, five between 5.0 and 6.0, twenty-five between 4.0 and 5.0, and twenty-six between 3.0 and 4.0.
Seismographs also logged sixty-two quakes between 2.0 and 3.0 and thirty events below magnitude 2.0 that people normally do not feel.
The last recorded event occurred eleven minutes ago and measured magnitude 3.9 in the Philippine Sea near Sarangani Island, its depth is unknown and it was not reported felt.
Context And Historical Seismic Rates
The Philippines have a very high level of seismic activity based on long term records, and averages drawn from the past 26 years and an archive reaching back to 1900.
On that basis the country averages about 14,000 earthquakes per year, a figure that reflects frequent small shocks across the archipelago and offshore waters.
Large earthquakes above magnitude 8 have occurred at least four times since 1900, a frequency that suggests such events happen infrequently, on average approximately every 30 to 35 years.
More detailed annual averages show roughly 3,000 quakes of magnitude 3 or higher, about 756 events of magnitude 4 or above, 73 of magnitude 5 or above, and approximately six quakes of magnitude 6 or higher each year.
These long term statistics provide context for the present swarm, indicating that while strong and damaging quakes are rare, the Philippines routinely experiences many smaller and moderate events.
