If coordinates are to be passed on to another person it is technically necessary to report the horizontal datum and the latitude/longitude of the point (e.g.
Generally, for the conterminous United States, the North American Datum (NAD) shift amounts to about 210 meters. This shift occurs because of the change in shape of the spheroid used to define the datum.
The National Geologic Map Database Data Portal is intended to: 1) give the user a quick browse and query of our Nation's geologic maps, in a standardized format, and 2) link the user to the source information found via the
An exhaustive database that provides bibliographic access to thousands of geologic, geophysical, and other kinds of maps available in USGS publications, Web sites, and in popular science journals.
As of late 2014, more than 95% of the historical USGS topographic maps - almost 179,000 map sheets - have been scanned and published. An estimated additional 4% are in process and are expected to be published in 2015 and 2016.
Trails and symbols are shown clearly. A comprehensive legend appears on each map. Since each map is unique, placement of the legend varies. 
The USGS has some great science fair ideas related to earthquakes. Find inspiration for projects on other science topics by browsing the USGS Education website.
Absolutely! The USGS has partnerships with many citizen science programs that are appropriate for classroom projects or for individual students. These programs include:
The USGS does not have any positions specifically targeted to teachers, but appropriate positions do exist.