The 1897 Mindanao earthquakes occurred on September 20, 1897, at 19:06 UTC and September 21, 1897, at 05:12 UTC. The estimated epicentres of the two

earthquake An earthquake (also known as a quake, tremor or temblor) is the shaking of the surface of the Earth resulting from a sudden release of energy in the Earth's lithosphere that creates seismic waves. Earthquakes can range in intensity, from ...

s are identical, lying just off the southwestern coast of

Mindanao Mindanao ( ) ( Jawi: مينداناو) is the second-largest island in the Philippines, after Luzon, and seventh-most populous island in the world. Located in the southern region of the archipelago, the island is part of an island group of ...

in the

Philippines The Philippines (; fil, Pilipinas, links=no), officially the Republic of the Philippines ( fil, Republika ng Pilipinas, links=no), * bik, Republika kan Filipinas * ceb, Republika sa Pilipinas * cbk, República de Filipinas * hil, Republ ...

, south of

Basilan Basilan, officially the Province of Basilan ( cbk, Provincia de Basilan; yka, Wilayah Basilanin; tsg, Wilaya' sin Basilan; fil, Lalawigan ng Basilan), is an island province of the Philippines located primarily in the Bangsamoro Autonomous Re ...

island. The earthquakes were originally given estimated magnitudes of 8.6 and 8.7 on the

surface wave magnitude The surface wave magnitude (M_s) scale is one of the magnitude scales used in seismology to describe the size of an earthquake. It is based on measurements of Rayleigh surface waves that travel along the uppermost layers of the Earth. This ma ...

scale by

Charles Richter Charles Francis Richter (; April 26, 1900 – September 30, 1985) was an American seismologist and physicist. Richter is most famous as the creator of the Richter magnitude scale, which, until the development of the moment magnitude scale in 19 ...

, but these were revised downwards by

Katsuyuki Abe is a former international table tennis player from Japan. Career Table tennis He won a bronze medal at the 1971 World Table Tennis Championships with Yujiro Imano and another with Shigeo Itoh at the 1975 World Table Tennis Championships. ...

to 7.4 and 7.5 , respectively. Contemporary reports noted that with few exceptions, all the masonry buildings in Zamboanga and

were left in ruins. Both earthquakes triggered

tsunami A tsunami ( ; from ja, 津波, lit=harbour wave, ) is a series of waves in a water body caused by the displacement of a large volume of water, generally in an ocean or a large lake. Earthquakes, volcanic eruptions and other underwater explo ...

s, with the second being quite destructive, with a maximum run-up of 7.0 m. The tsunami was noted all along the southwest coast of

Negros Negros is the fourth largest and third most populous island in the Philippines, with a total land area of . Negros is one of the many islands of the Visayas, in the central part of the country. The predominant inhabitants of the island region a ...

, the west coast of

Panay Panay is the sixth-largest and fourth-most populous island in the Philippines, with a total land area of and has a total population of 4,542,926 as of 2020 census. Panay comprises 4.4 percent of the entire population of the country. The City o ...

, the south coast of

Palawan Palawan (), officially the Province of Palawan ( cyo, Probinsya i'ang Palawan; tl, Lalawigan ng Palawan), is an archipelagic province of the Philippines that is located in the region of Mimaropa. It is the largest province in the country in ...

, the west coast of

, and the east coast of

Borneo Borneo (; id, Kalimantan) is the third-largest island in the world and the largest in Asia. At the geographic centre of Maritime Southeast Asia, in relation to major Indonesian islands, it is located north of Java, west of Sulawesi, and eas ...

. At least 13 died as a result of the second tsunami, with a hundred or more casualties also being reported.

References

{{Earthquakes in the Philippines Earthquakes in the Philippines 1897 earthquakes History of Basilan History of Zamboanga City History of Sulu September 1897 events 1897 in the Philippines

Earthquakes An earthquake (also known as a quake, tremor or temblor) is the shaking of the surface of the Earth resulting from a sudden release of energy in the Earth's lithosphere that creates seismic waves. Earthquakes can range in intensity, from ...

See also

References