Makassar Strait

The Makassar Strait (Indonesian: Selat Makassar) is a strait between the islands of Borneo and Sulawesi in Indonesia. It connects the Celebes Sea to the north with the Java Sea to the south. This important waterway is a key route for ships moving through Southeast Asia.

Several rivers flow into the strait, including the Mahakam River and the Karangan River from Borneo. Major ports along its edges include Balikpapan, Bontang, Makassar, Palu, and Parepare. The city of Samarinda lies close to the strait, about 48 kilometers (30 miles) away along the Mahakam River.

Extent

The International Hydrographic Organization says the Makassar Strait is one of the waters in the East Indian Archipelago. It is the channel between the east coast of Borneo and the west coast of Sulawesi.

The northern edge of the strait is a line joining Tanjong Mangkalihat on Borneo and Cape Binar on Sulawesi. The southern edge is a line from the southwestern tip of Sulawesi, through the southern point of Tana Keke, to the southern tip of Laoet and then to Tanjong Petang on Borneo.

Geology

The Makassar Strait and North Makassar Basin formed because of movements in the Earth's crust. One piece of the Earth's crust moved under another, creating space for the strait. Over time, sand and mud filled this space. This area has large amounts of oil and natural gas, especially in the Kutei Basin.

The movement of another piece of the Earth's crust changed the position of the island of Sulawesi, helping create the southern part of the Makassar Basin.