Unexplained MovementThe lands we know today as certain continents may not have existed in their current position long ago. As technology advances in oceanography, it has been learned that there are many activities beneath the surface of land and oceans that can contribute to changes in land mass. These changes include wave erosion, volcanic activity and lithospheric pressures. Plate tectonics was developed through a theory formerly called continental drift. In the development of plate tectonics, continental drift helped form the hypothesis of a shift in land mass and sea floor. In 1850, a scientist in the U.S. Navy's Department of Charts and Instruments discovered the Mid-Atlantic Ridge while attempting to map the seafloor (Salem 1999). The technology of the time did not allow the depth or characteristics of the ridge to be measured. In the mid-1900s, additional studies of the seafloor revealed that the Mid-Atlantic Ridge had a valley, which was found to be seismically correlated with many earthquakes (Salem 1999). These results support the assertion of landmass movement. Additionally, the findings lent themselves to the possibility of a new seafloor created as a result of seismic activity since valleys were discovered along the ridge, rather than canyons. Wegener's Theory Continental drift was a far-fetched theory when German scientist Alfred Wegener first proposed it in 1915. At the time, many geologists were convinced "that continents and ocean basins had geographical positions fixed”. (Lutgens Tarbuck 2014). Wegener was a professional meteorologist, not a geologist. He studied the atmosphere and weather (Hoffman 2012) and participated in scientific expeditions to measure temperatures or factors contributing to his studies. His experience...... middle of paper ......h along the boundaries of each major seafloor ridge also helped develop plate tectonic theories. These theories better explain why some land boundaries diverge instead of converging or transforming, as well as the impacts on land and seabed. As satellite technology advances to measure the movements of different areas, civilizations can prepare for changes in climate and living conditions. ReferencesSalem, P. (1999). Hess identifies seafloor spreading as the cause of continental drift. In , Great Scientific Achievements (p. 718). United States: Salem Press. Conniff, R. (2012). When the Earth moved. Smithsonian, 43(3), 36-38Hoffman, P.F. (2012). Tooth of Time: Alfred Wegener. Geosciences Canada, 39(3), 102-111. Lutgens, F. K. and Tarbuck, E. J. (2014). Foundations of Earth Sciences. 7th ed. Upper Saddle River, NJ: Pearson Education, Inc..