University of Phoenix Material
Earth’s Dynamic Ocean and Atmosphere I Worksheet
From Visualizing Earth Science, by Merali, Z., and Skinner, B. J, 2009, Hoboken, NJ: Wiley. Copyright 2009 by Wiley. Adapted with permission.
Sections 12.1 and 12.2 of the text discuss the origin and composition of the world ocean’s seawater.
1. What is the current theory on the evolution of the world ocean?
Scientists do not yet agree as to where the Earth's water came from. According to the text, some water were in the materials that formed Earth. That water was released as steam from volcanoes. The text also states that more water could have came from outside sources such as comets and meteorites.
2. Discuss the origin of the salinity of seawater and how the ocean maintains salinity.
Chemical weathering of rock and volcanic eruptions are some of the sources that are involved in the salinity of seawater. Evaporation of surface water and freezing of seawater makes seawater saltier. While rain, snow, and river water make it less salty.
Surface currents obtain their energy from the wind blowing over the surface waters. The currents do not exactly follow the wind direction because of an apparent force known as the Coriolis force. Using Figure 12.11 from the text, briefly explain surface currents of the world ocean and how the Coriolis force affects this movement in the Northern and Southern Hemispheres.
Surface currents of the world are the cold western boundary currents, the North Atlantic drift, and the Circumpolar current. The Cold western boundary currents are in the Northern Hemisphere, where there are continental boundaries in high latitudes. The cold equatorward currents flow along the east side of the continents. There they meet up with poleward-flowing western boundary currents in the midlatitudes. The Circumpolar current is in the Southern Hemisphere. There the absent of continental boundaries allow the strong west winds around...