The figure-eight shaped island is about 60 kilometres (37 mi) at its longest, about 15 kilometres (9.3 mi) at its widest and about 5 kilometres (3.1 mi) at the narrowest section. The volcanic island is dotted with cinder cones, tuff cones, pyroclastic cones, maars and crater lakes.
The highest point in the island is Mount Tumatangas[2] with an elevation of 811 metres (2,661 ft) asl. Bud Dajo has an elevation of 620 metres (2,030 ft) asl.
Guimba, Matanding, and Sungal, are some other volcanic cones near Bud Dajo. Four crater lakes are located on the island: Lake Seit, Lake Panamao and Lake Timpuak and Sani Crater Lake. Solfataric activity is found at Seit Lake.
Volcanic activity
On January 4, 1641, a volcanic eruption covered much of Mindanao in darkness and sent showers of ash as far as Cebu and Panay. It was reported at the time as being from a small island "opposite the main river of Jolo" and the only possible source of eruption in Jolo is Mount Dakula near Lake Panamao.[3] From recent studies, the eruption was finally attributed to Mount Parker in South Cotabato.
A tsunami occurred in 1897, believed to have been caused by a local submarine eruption on September 21, 1897. It is possible this eruption was centered at Lake Seit, a volcanic maar with still active solfatara.
Volcanoes in the Jolo Group are young and considered active on the probable eruptions above.
Jolo Group is part of the Sulu Volcanic Arc, one of the two northeastern arms of the Sunda Plate which is in collision with the Philippine Mobile Belt. It is an area of frequent earthquakes and volcanic activity.
Like most volcanos in the former Sultanate of Sulu, the group is little studied scientifically.