One of the primary tasks of the USGS was to create accurate maps of the United States, and in 1884, one of the first USGS topographical maps was published. This map covered an area of 4,000 square miles in central Montana and was created using the latest surveying and mapping techniques ...
this defined an operational bandwidth that would need to be lowered to at least the period of the Earth's gravest normal mode,0S2—approximately 54 min. The upper frequency limit was initially set to 10 Hz based on the intent to use the network primarily for regional and teleseismic (global...
Frick WF, Pollock JF, Hicks AC, Langwig KE, Reynolds DS, Turner GG, Butchkoski CM, Kunz TH (2010) An emerging disease causes regional population collapse of a common North American bat species. Science 329: 679-682. DOI:10.1126/science.1188594 Article CAS PubMed Google Scholar Friend ...