Official websites use .gov
A .gov website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS
A lock () or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
This device, about the size of a large shoebox, records strong ground motions and sends the measurements to the U.S. Geological Survey over the Internet. The data collected is available to assist with emergency response following an earthquake.
Public Domain.
