Landsat Spots Foundered Ships in Coastal Waters
An estimated 3 million shipwrecks are scattered across the planet’s oceans. Most maritime mishaps take place close to shore where hazards to navigation — such as rocks, reefs, other submerged objects and vessel congestion — are abundant. While there is a romantic association of shipwrecks and buried treasure, it is desirable to know where they are located for many other practical reasons. The ships may be of historical significance or, if the hard substrate of the ship has created a reef, of ecological significance. Modern-era shipwrecks are also commonly sources of pollution, leaking onboard fuel and corroded heavy metals. Nearshore shipwrecks can be navigational hazards themselves.
Researchers have found that shipwrecks near the coast can leave sediment plumes at the sea’s surface that help reveal their location. Using data from the NASA/USGS Landsat 8 satellite, researchers have detected plumes extending as far as 4 kilometers (about 2.5 miles) downstream from shallow shipwreck sites. This discovery demonstrates for the first time how Landsat and Landsat-like satellites may be used to locate the watery graves of coastal shipwrecks.