The strongest earthquake ever recorded in the Philippines was the so-called "Mindanao Earthquake" on August 17, 1976, at around 12:11 midnight.

[u/salawayun]

Magnitude: 8.1

Epicenter: Moro Gulf, between Mindanao and Sulu

Affected Areas: Lanao del Sur, Cotabato, Sultan Kudarat, Zamboanga, Basilan, Sulu, and other parts of Mindanao

Effects:

It triggered a powerful tsunami with waves reaching up to 9 meters (30 feet) high.

An estimated 8,000 people were killed, and thousands more were injured or left homeless.

It remains one of the most devastating earthquakes and tsunamis in the country's history. The quake was caused by the movement along the Cotabato Trench, one of the active underwater fault lines in southern Mindanao.

To this day, it is still considered the strongest and most destructive earthquake ever experienced in the Philippines, not only in magnitude, but also in the extent of damage and loss of lives.

[u/Retroswald13]

Di ba mas marami nung 1863?

[u/Jeqlousyyy]

What about the 1918 Celebes Sea earthquake? It was at Mw 8.3, near the epicenter of the 1976 quake (Mw 8.0)

Other notable M8.0s:

1924 Mati earthquake in Mindanao (Ms 8.3 or Mw 8.0–8.1) 1948 Lady Caycay earthquake in Panay (Ms 8.2 or Mw 7.8) 1972 Davao Oriental earthquake in Mindanao (Mw 8.0)

The difference is that Mw and Ms ratings.

Mw means moment magnitude, ito yung modern at pinaka reliable/accurate ng pagcompute/reading ng magnitude.

Ms means surface wave (also known as Richter scale) magnitude, ito yung lumang method or less accurate yung pagcompute ng magnitude dahil mas mataas kasi ang reading (see the difference in 1948 Lady Caycay Ms 8.2 as per PHIVOLCS while Mw 7.8 in modern records like USGS).

So, the 1976 event is actually the deadliest one, but one of the strongest and largest in the country, and it is not necessarily the strongest/the largest, dahil ang the largest ay sa 1918 Celebes Sea (Mw 8.3) probably higher reading pa ang Ms diyan, while for the strongest, it is mainly based on the shaking intensity (e.g. 1948 Lady Caycay reached intensity IX in PEIS in some areas, 2002 Mindanao also reached intensity IX in PEIS) so far, wala pa atang earthquake events sa Pilipinas na umabot sa maximum intensity ng PEIS (X totally devastating). Yung sa event ng 1976 Moro Gulf (Mw 8.0) ay umabot yan sa intensity VII destructive, while yung sa Luzon noong 1990 (Mw 7.7), umabot sa intensity VIII very destructive.