Science and Exploration

Mining on Semirara Island As Seen From Orbit

By Keith Cowing
May 24, 2013
Filed under

Panian Mine on Semirara Island, Philippines is featured in this image photographed by an Expedition 23 crew member on the International Space Station. This detailed view provides a rare, cloud-free view of the northern end of Semirara Island located approximately 280 kilometers to the south of Manila.

Panian Mine on Semirara Island, Philippines is featured in this image photographed by an Expedition 23 crew member on the International Space Station. This detailed view provides a rare, cloud-free view of the northern end of Semirara Island located approximately 280 kilometers to the south of Manila.

The northern part of the island is dominated by the Panian Coalfield (center), the largest of three coalfields on the island. According to scientists, the coalfields were formed between 12-23 million years ago along what was then a coastal plain — not unlike the current geologic environment of the southeastern Gulf Coast of the United States. Organic materials were deposited in sequences of sandstone and mudstone, which were then covered by limestone as the environment became progressively more marine. Over geologic time, increased pressure from the overlying rocks changed the layers of organic material into coal. The Panian coalfield is being mined using open-pit methods. The rock and soil above the coal layers (or seams) is known as overburden. Overburden is removed from the pit and heaped into spoil piles, several of which are visible ringing the northern half of the pit.

Several of the dark coal seams are visible along the sunlit southern wall of the pit. Plumes of sediment coming off of the spoil piles and entering the Sulu Sea are visible along the northern and eastern coastline of the island. Coal from the Panian open-pit mine is used primarily for energy generation in the Philippines, with some exported to India and China. high res (1.0 M) low res (61 K)

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