Upper (left to right):
- US steam frigate Mississippi, in the Gulf of Mexico, March 1847: Library of Congress, Prints & Photographs Division [reproduction number LC-USZC2-3129] (originally published by N. Currier, New York, 1848).
- Florida peninsula, January 1985: NASA Space Shuttle Earth Observations Photography database [photo STS51C-44-0026].
- TAO (Tropical Ocean Atmosphere) buoy and anemometers on NOAA ship Ka'imimoana. Photo by Jason Poe, courtesy of TAO Project Office.
Lower (left to right):
- Iceberg B10A Calving, 1999 (image courtesy Landsat 7 project, NASA).
- Thomson, C.W., 1878: The Voyage of the Challenger: the Atlantic: A Preliminary Account of the General Results of the Exploring Voyage of H.M.S. Challenger during the Year 1873 and the Early Part of the Year 1876. New York, Harper & Brothers (from vol. 1, p. 65, photograph courtesy of the NOAA Photo Library).