Friday March 25, 2011 (Introduction to Oceanography)

The Launch Pad Friday, 3/25/11 What is “salinity? Describe the term as it applies to Earth’s oceans. Salinity is the amount of dissolved minerals in a given amount of water. Ocean water is 3.5% mineral content, or 35 0 /oo

Announcements If you have not yet taken Test 8, see me ASAP!

Assignments For This Six-WeeksDate IssuedDate Due Video Quiz - Lakes, Rivers, and Other Water Sources 2/27 WS - Running Water and Groundwater (Part 1) 2/253/4 PowerPoint Project – Rivers (P5 only) 2/283/3 WS - Running Water and Groundwater (Part 2) 3/23/9 Video Quiz - Groundwater3/3 Cornell Notes - Ice3/83/9 WS - Ice3/93/25 Test 83/11 Video Quiz – Ocean’s – Earth’s Last Frontier 3/23

Cornell Notes Introduction to Oceanography

Oceanography

The Composition of Seawater Seawater consists of about 3.5% (by weight) dissolved minerals. Salinity refers to the total amount of solid material dissolved in water. Salinity is typically expressed in parts per thousand (‰) The average salinity of seawater is 35‰, with the major constituent being sodium chloride

The Composition of Seawater Sources of Sea Salts chemical weathering of rocks on the continents and subsequent inflow from rivers outgassing from volcanic eruptions

The Composition of Seawater Processes Affecting Seawater Salinity Variations in salinity are a consequence of changes in the water content of the solution. Processes that decrease salinity (add water) include: precipitation runoff from land icebergs melting sea ice melting

The Composition of Seawater Processes Affecting Seawater Salinity Variations in salinity are a consequence of changes in the water content of the solution. Processes that increase salinity (remove water) include: evaporation formation of sea ice

The Composition of Seawater Surface salinity in the open ocean ranges from 33‰ to 38‰.

Processes Affecting Seawater Salinity increase seawater salinity decrease seawater salinity

A desalination plant that removes salts and other chemicals from sea water to produce fresh water.

Ocean Temperature Surface water temperature varies with the amount of solar radiation received. Lower surface temperatures are found in high-latitude regions. Higher surface temperatures are found in low-latitude regions. The unique thermal properties of seawater make it resistant to temperature changes. However, global warming could eventually influence ocean temperatures.

Ocean Temperature Variation with Depth In low latitudes, there is a high temperature at the surface, with a rapid decrease in temperature with depth. This indicates the presence of a thermocline. In high latitudes, there are cooler surface temperatures with no rapid change in temperature with depth.

Variations in the Ocean’s Surface Temperature and Salinity with Latitude Figure 14.3