The Night the Earth Shook
It was 5:58 p.m. on Christmas Day 2004 in Golden, Colorado, when the first seismic waves arrived from halfway around the world. A massive magnitude 9.1 earthquake that had just struck off the coast of Sumatra at 7:58 a.m. local time sent vibrations racing through the Earth's crust at several kilometers per second, eventually reaching the sensors that track global seismicity at the USGS National Earthquake Information Center (NEIC). Inside the building nestled in the foothills of the Rocky Mountains, the skeleton crew working the holiday shift noticed something dramatic. Their computer screens were lighting up with incoming data from