|Elevation||862 m (2,828 ft)|
|Listing||List of potentially active volcanoes in the Philippines|
|Location||Sarangani, Davao Occidental, Philippines|
|Volcanic arc||Central Mindanao Arc|
Balut Island, also known as Malulong, is a volcanic island south of the tip of Davao Occidental province in the Mindanao region, Southern Philippines. Located in the center of the island is the Balut Volcano, a fumarolic volcano with no historical eruptions.
The island of Balut is located about 13 km (8.1 mi) from mainland Mindanao, separated by the Sarangani Strait. Balut, Sarangani and Olanivan Islands make up the island group known as the Sarangani Islands. The group comprises the Municipality of Sarangani of Davao Occidental. Mabila on Balut Island is the town's center for commerce and the local government.
Balut is subdivided into 8 barangays:
Balut Island, the westernmost of the Sarangani Islands, is the larger, higher, and better cultivated than Sarangani Island. In the center of the island is Balut Volcano, which is fumarolic on occasion. Balut Island rises to about 1,800 metres (5,900 ft) from the seabed with the highest elevation at 862 metres (2,828 ft) above mean sea level. Base diameter of the island is 8 kilometres (5.0 mi).
If seen from the northwest, it appears between two peaks. Northeast is another peak of Balut, southwest of the peak is the Langab volcano. In the southeast part of the island is Ten Seventy Hill with an elevation of 1,083 feet (330 m).
The north and east coasts are bordered by a reef, which in some places extends out over 1 mile, while on the south and west sides the fringing reef does not extend out to any distance. Off the southwest point is a rock island called Manamil Island with an elevation of 40 feet (12 m). Lajan Point, the northeast point of the island, is low and covered by mangroves.
South of the Lajan Point is Mabila, which is the poblacion or town center of the Municipality of Sarangani. The Port of Mabila is the main port of entry to the island and the gateway to the rest of the municipality.
Balut is classified by Philippine Institute of Volcanology and Seismology as a potentially active stratovolcano with solfataric activity. Hot springs and thermally altered grounds with temperatures of 95–96 °C (203–205 °F) are located at the west and Ssouthwest basal slopes of Balut Volcano. Temperature at the Palabuno Hot Spring is 42 °C (108 °F).
There are no reports of eruptions in historical times. The January 4, 1641 eruption that enveloped most of Mindanao in darkness was falsely attributed to Balut Volcano, as well as other volcanoes in the Philippines. Later studies proved that the eruption came from Mount Parker, 80 kilometres (50 mi) NW of Balut Island.
Rock type on the volcano is predominantly basalt and andesite. Balut is part of the Central Mindanao Arc, an area of frequent earthquakes and volcanic activity. All volcanoes in the Philippines are part of the Pacific ring of fire. Like most volcanoes in southern Philippines, Balut Volcano is little studied scientifically.
- List of active volcanoes in the Philippines
- List of potentially active volcanoes in the Philippines
- List of inactive volcanoes in the Philippines
- List of islands of the Philippines
- "Balut". Global Volcanism Program. Smithsonian Institution.
- Bureau of Insular Affairs (1902). ;"A Pronouncing Gazetteer and geographical Dictionary of the Philippine Islands", p.325. Washington Government Printing Office.
- U.S. Army Corps of Engineers (1954). "Caburan (topographic map)". University of Austin Library. Retrieved on 2013-11-04.
- (2010-12-04). "PPA devolves Mabila Port to Sarangani LGU". Philippine Information Agency.
- "Balut". Philippine Institute of Volcanology and Seismology. Retrieved on 2013-11-04.
- "Parker". Global Volcanism Program. Smithsonian Institution. Retrieved 2011-03-02.