The USGS Global Visualization Viewer requires Java 7 or higher. In my Funtoo box I have:
java -version
java version "1.7.0_51"
Java(TM) SE Runtime Environment (build 1.7.0_51-b13)
Java HotSpot(TM) 64-Bit Server VM (build 24.51-b03, mixed mode
Isn't this already version 7? How do I get past this obstacle? I currently use Firefox which features (the plugin) IcedTea-Web ver. 1.3.2. I have also been through http://www.funtoo.org/Funtoo_Linux_Web_Browsers#Oracle_Java_Runtime_Environment to ensure it was not a "Security" misconfiguration.