ByEdd Gent-Live Science Contributor8 hours ago

One way to create an EMP is to set off a nuclear bomb. Here, a billowing white mushroom cloud during Operation Ivy, the first test of a hydrogen bomb, at Enewetak Atoll in the Marshall Islands.(Image credit: CORBIS/Corbis via Getty Images)

A U.S. Air Force base in Texas has taken the first steps to guard against an electromagnetic pulse (EMP) attack. But what, exactly, is an EMP, and how big is the threat?

Officials at the Joint Base San Antonio in Lackland, Texas, issued a request for bids to carry out a survey of a facility called the Petroleum, Oil and Lubrication Complex. The survey will identify any equipment that could be vulnerable to an EMP ahead of more detailed vulnerability testing, according to the request. After that, officials would figure out ways to keep that equipment safe in the event of…