In times of crisis and natural disasters, Amateur radio is often used as a means of emergency communication when wire line, cell phones and other conventional means of communications fail.
Unlike commercial systems, Amateur radio is not as dependent on terrestrial facilities that can fail. It is dispersed throughout a community without "choke points" such as cellular telephone sites that can be overloaded.
Amateur radio operators are experienced in improvising antennas and power sources and an automobile battery today can power most equipment. Annual "Field Days" are held in many countries to practice these emergency improvisational skills. Amateur radio operators can use hundreds of frequencies and can quickly establish networks tying disparate agencies together to enhance interoperability.
Recent examples include the 2001 attacks on the World Trade Center in Manhattan, the 2003 North America blackout and Hurricane Katrina in September, 2005, where amateur radio was used to coordinate disaster relief activities when other systems failed.
On September 2, 2004, ham radio was used to inform weather forecasters with information on Hurricane Frances live from the Bahamas. On December 26, 2004, an earthquake and resulting tsunami across the Indian Ocean wiped out all communications with the Andaman Islands, except for a DX-pedition that provided a means to coordinate relief efforts.
The largest disaster response by U.S. amateur radio operators was during Hurricane Katrina which first made landfall as a Category 1 hurricane just north of Miami, Florida on August 25, 2005, eventually strengthening to Category 5. More than a thousand ham operators from all over the U.S. converged on the Gulf Coast in an effort to provide emergency communications assistance. Subsequent Congressional hearings highlighted the Amateur Radio response as one of the few examples of what went right in the disaster relief effort.
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