Guest Column by GeoT
Dateline: 10/01/00
Looking at a map of the island of New Guinea, among the many interesting items to be seen, is a river. The Fly River. Curious name, but not too hard to believe for this part of the world! As it turns out, it is named 'Fly' for a very different reason.
The Fly is a major river of the island. It flows through Papua New Guinea almost entirely except for a short stretch where it forms part of the border with Indonesia's Irian Jaya. That shows up as that little bend along the normally straight north south boundary.
The Fly originates in high in the Central Mountains, in the Victor Emanuel Range, which was produced by folding and thrust faulting along the northern edge of the Australian plate. Peaks here tower over 13,000 feet and equatorial rains total nearly 400 inches per year. These factors combine to create a rapid-running, gorge-cutting, landslide-producing river! Landslides account for most of the load carried by the Fly River. Over 700 miles later the sediment acquired here is deposited as a broad alluvial lowland bordering the Torres Strait. At the junction with the Palmer River, the Fly flattens its gradient substantially as it then crosses the nearly level Quaternary deposits of the alluvial Fly Platform. The character of the river changes dramatically from that of a charging mountain torrent to a lazy, aggrading, meanderer with a 40-mile wide mouth.
The Fly is the world's 23rd largest river. Flooding can occur from October to April, which contributes huge amounts of sediment to the alluvial lowland and the building sandbars and islands. The Fly is navigable upstream from the Gulf of Papua for 540 miles to the junction with the Palmer River for shallow draft vessels.
There is little economic activity and few people living along the Fly's course, save for a few coconut plantations and crocodiles being hunted. Upstream is a different story. On the OkTedi, and Strickland, tributaries of the Fly, are copper and gold mining operations. The same slopes that are prone to sliding naturally preclude conventional tailings ponds and methods of mine waste containment. As a result, the waste is disposed of in the rivers, which then adds to the total sediment load of the entire system. Studies are underway to assess the impact of this increase in sediment to the hydrology of the Fly drainage basin.
But, the Fly wasn't named for a pesky insect -- it was named for a ship. In 1842, Captain F. P. Blackwood discovered the mouth of the Fly River and named it for the ship he commanded -- the HMS Fly!
Sometimes, geographic names are fairly obvious in origin. Sometimes -- they're not!
GeoT is a long-time high school geography teacher from Illinois. In addition to geography, he enjoys railroads and model railroads, old Oldsmobiles, and gardening.
