Why is the Source to Sink Program focused on the Fly River in Papua New Guinea?

For several reasons:

• Rugged, Young Mountains
  The island of New Guinea lies in an active margin setting, and a chain of rugged, young mountains, many more than 2000 m (6562 ft) in elevation, extend along the axis of the island. The Fly River drains this region.
  
• High Rainfall Rates
  Over the mountains of New Guinea annual rainfall rates are more than 10 m/year (33 ft/year). As a comparison, New York City receives approximately 47 inches annually or 3.9 ft/year (1.2 m/year).
  
• Large Sediment Supply Signal to Ocean
  Factors listed in #1 and #2 along with the humid climate and earthquake activity are responsible for a tremendous discharge of sediment and dissolved material from New Guinea to the coastal ocean. In total, it is estimated that the island contributes 1.7 billion metric tonnes (3.7 trillion lbs.) of sediment to the ocean annually, approximately 1.5 times the sediment discharge of the Amazon River (Milliman). Furthermore, New Guinea and five islands of the Indo-Pacific region are estimated to contribute 20-25% of the total sediment discharge to the ocean, emphasizing the critical importance of the area to the ocean.
  
• Wide Continental Shelf
  The Fly River discharges its large sediment load onto a relatively wide continental shelf. Therefore, the primary marine depocenter (i.e., the location where most sediments deposit) is immediately seaward of the river mouth, and this is likely an excellent record of past sediment discharge.
  
• An Undisturbed System
  Unlike most large rivers around the world, the Fly River drainage basin has been relatively undisturbed by humans. Two mines are found along the river system, but otherwise, urban development is essentially absent in the 75,000 km2 catchment.
  
• Existing Data
  Because Ok Tedi mine is located on the Fly River system, the river has been well studied and a considerable amount of data (e.g., river gauge measurements) exists for this relatively remote river. Also, a significant amount of preliminary sedimentological and geochemical research has been conducted on the shelf seaward of the mouth of the Fly River. Consequently, the basic mechanics of sediment dispersal and accumulation throughout the system are believed to be understood.