September 21, 1897 Tsunami: Sulu Sea, Philippines

Reference #414:

1897, September 21, 13:15 [local time]. There was a destructive earthquake on the southwest of the Philippine Islands, with a maximum intensity of VIII (IX Rossi-Forel).

The steamship "Brutus", situated near Zamboanga, felt a strong seaquake. Waves arose, moving to the east and breaking on shore near Zamboanga about 10 minutes later.

At Zamboanga, about 15:00 (local time), an earthquake recurred with the same force as the preceding one. Then a phenomenon occurred which caused great panic. The sea level fell 5 m, and then rose and fell with great speed. After several such oscillations in level, sea waves began to flood the city, although they did not advance further than the first few homes. The water picked up proas riding off shore and left them high and dry. According to eyewitnesses, the greatest oscillations in level were observed from 15:00 to 16:00, and at 16:00, the second of the strongest waves arrived. The phenomenon lasted a little less than 2 hours.

At Isabela, about half an hour after the earthquake, water burst with a roar into the northeastern passage leading to the port. The enormous waves moving from the west washed away everything on shore; the sea level rose at least 7 m above the usual mark. The sea rose and fell more than 30 times, and one of the waves was considerably larger than the others. The waves broke on shore with such force that they easily rolled building timber 6 m long and pieces of masonry. A grocery store was washed away, 25 homes were destroyed, and the gunboat General Laso was imperiled.

There were victims on the farms of the Moro tribe: at Panigayan, two injured: at Balauan, five dead, six injured; at Labotan, three dead, six injured; at Matiban, five dead, homes destroyed; eight homes were washed away at Tagu.

An eyewitness on a boat riding at anchor in Sibuguey Bay, related that the water raised the boat together with its two anchors several times and the ship was in great danger.

At Dapitan Port, the sea rose 2 m at the head of the bay.

At Negros Island, at noon a boat was crossing the bay; its movements were almost totally paralyzed by the waves.

On Jolo Island, 15 minutes after the earthquake, the sea began to rise and fall at 15 minute intervals, retreating 200-250 m from shore. The maximum height of rise of water was 1 m. The rough sea calmed by 21:30 (L.T.).

On Siau Island, Indonesia, the first drop in level was observed 1.5 hours after the earthquake. In 1/2 hour, the water retreated far beyond the ebb tide mark. Then it returned, reaching the flood tide mark in a few minutes.

Tsunami reports also came from the north coast of Calimantan island (Kudat region) and from the eastern shore of Sumatra Island.

Between Labuan Island and the coast of Calimantan Island, where the depth of the water had been 6 m, a new little island quietly rose out of the water after 13:00 on the 21st. The island was made up of clay and pebbles and was 200 m long, 150 m wide, and 20 m high. Its surface gave off hot gases and there was a strong petroleum smell. It is possible that the island was built up by the tsunami waves; on the other hand, the island could have also been the result of an underwater mud eruption.

Reference #1072:

A tsunami claimed claimed hundreds of victims on the western shores of Basilan.

Reference #1058:

100 victims due to the tsunami.

Reference #12917:

P. Sulu: The first wave struck after the second earthquake at 3:15 p.m. About 25 buildings were damaged and submerged. Negros: The market sustained damage. Some livestock were lost on farms.