Earthquake data from http://earthquake.usgs.gov/research/data/centennial.php. As per http://www.usgs.gov/laws/info_policies.html, this data is in the public domain. Credit: U.S. Geological Survey Department of the Interior/USGS Earth texture from http://earthobservatory.nasa.gov/Features/BlueMarble/BlueMarble_monthlies.php As per http://www.jsc.nasa.gov/policies.html#Guidelines, this data is in the public domain. Data produced by NASA’s Earth Observatory