The more natural way that this could happen is with a severe geomagnetic disturbance, or GMD.

发生这种情况的更自然的方式是发生严重的地磁扰动（GMD）。

This is called the Ground-based Midcourse Defense system, or GMD.

这称为陆基中段防御系统或 GMD。

First the rocket carrying the missile is detected, and when that happens the GMD gets ready.

首先检测到携带导弹的火箭， 当这种情况发生时， GMD 就准备好了。

The United States does have defense programs, like the Ground-based Midcourse Defense, or GMD,   to protect American cities from certain nuclear attacks.

美国确实有防御计划，例如陆基中段防御（GMD），以保护美国城市免受某些核攻击。

Now, you'll likely have some strategic warning of a GMD, anywhere from around 18 hours to a few days, but a HEMP could potentially happen without any real warning.

你可能会收到地磁扰动的一些战略警告，从18小时到几天不等，但高空电磁脉冲有可能在没有任何真正警告的情况下发生。

To get more into the specifics, according to the US Department of Energy, a GMD and the E3 waves of a HEMP are going to put similar equipment and technologies at risk.

根据美国能源部的说法，为了了解更多细节，地磁扰动和高空电磁脉冲的E3波将把类似的设备和技术置于危险之中。