In the three weeks since the April 20th explosion and sinking of the Deepwater Horizon oil rig in the Gulf of Mexico, and the start of the subsequent massive (and ongoing) oil leak, many attempts have been made to contain and control the scale of the environmental disaster. Oil dispersants are being sprayed, containment booms erected, protective barriers built, controlled burns undertaken, and devices are being lowered to the sea floor to try and cap the leaks, with little success to date. While tracking the volume of the continued flow of oil is difficult, an estimated 5,000 barrels of oil (possibly much more) continues to pour into the gulf every day. While visible damage to shorelines has been minimal to date as the oil has spread slowly, the scene remains, in the words of President Obama, a "potentially unprecedented environmental disaster." ( 40 photos total