The deep sea earthquake and resulting Tsunami that killed hundreds of thousands of people in 2004 was a natural disaster of epic proportions. There's no way it could have been avoided, the tectonic plates that caused the quake had simply reached their breaking point. However, people living in India and Sri Lanka could have been alerted before the tsunami hit their communities. Sadly, there were no adequate warning systems in place.
The Pacific Rim earthquake zones near the northwest coast of the United States breed tsunami-causing earthquakes. To prepare for a tsunami-causing earthquake, scientists have devised an early-detection and measurement system called DART, which stands for Deep-Ocean Assessment and Reporting of Tsunamis. A network of DART buoys are placed strategically offshore, near areas where they should be able to detect a tsunami within thirty minutes of its formation.
Here's how the DART measurement system works. Every hour, water pressure recorders on the sea floor send four measurements, spaced 15 minutes apart. When a tsunami-like wave passes overhead, the computer on the seafloor detects the tsunami and immediately begins relaying measurements to the buoys. The buoys then transmit the data via satellite to Tsunami Warning Centers that use the data to determine if the tsunami is potentially dangerous. If so, towns and cities in its path will be alerted within minutes.
The DART system works very well, and a number of tsunamis have been measured and reported since the system began operation in 1998. Hopefully, when the time comes DART will help save thousands of lives.