A very strong earthquake with a preliminary magnitude of 7.2 (PHIVOLCS) hit near the coast of Mindanao, Philippines at 03:39 UTC (11:39 LT) on December 29, 2018. The agency is reporting a depth of 54 km (33 miles). Both USGS and EMSC registered it as M7.0 at a depth of 60 km (37 miles).
Minor sea level disturbances such as strong currents and rapid rise and fall of seawaters are expected, PHIVOLCS said. The concerned public is advised to be on alert for unusual waves.
“Based on tsunami wave models and early tide gauge records of the tsunami in the Philippine Sea, coastal areas in Philippine provinces fronting the Philippine Sea are expected to experience wave heights of less than one meter above the normal tide levels. The first tsunami waves will arrive between 12:00 PM to 02:00 PM, December 29, 2018 (PST) and may not be the largest.
“These waves may continue for hours. People are advised to STAY AWAY FROM THE BEACH AND NOT TO GO TO THE COAST fronting the Philippine Sea of the following provinces during this 12:00 PM to 02:00 PM, and until the threat has passed: Compostela Valley Davao Del Norte Davao Del Sur Davao Oriental Davao City Sarangani South Cotabato Agusan Del Norte Agusan Del Sur Surigao Del Norte Surigao Del Sur People whose houses are located very near the shoreline of these provinces are advised to MOVE FARTHER INLAND.
“Owners of boats in harbors, estuaries or shallow coastal water of the abovementioned provinces should secure their boats and move away from the water front. Boats already at sea during this period 12:00 PM to 02:00 PM should stay offshore in deep waters until further advised.”
According to the USGS, the epicenter was located 84 km (52 miles) ESE of Pondaguitan (population 2 143), 128 km (80 miles) SSE of Mati (population 105 908), and 131 km (82 miles) E of Caburan (population 12 618), Davao, Philippines.
There are about 20 000 people living within 100 km (62 miles).
16 000 people are estimated to have felt strong shaking, 539 000 moderate, and 13 936 000 light.
The USGS issued a green alert for shaking-related fatalities and economic losses. There is a low likelihood of casualties and damage.
Overall, the population in this region resides in structures that are a mix of vulnerable and earthquake resistant construction. The predominant vulnerable building types are unknown/miscellaneous types and heavy wood frame construction.
Little or no landsliding and liquefaction is expected, but some could have occurred in highly susceptible areas.
There have been no immediate reports of casualties or damage.
Estimated population exposure to earthquake shaking
Selected cities exposed
Featured image credit: Google, TW/SAM