Ocean Water & Ocean Life 15.1 The Composition of Seawater 4/18/2019

Did You Know? If you could remove the salt in the sea could be removed and spread evenly over the Earth's land surface it would form a layer more than 500 feet thick, about the height of a 40-story office building 4/18/2019

Introduction What is the difference between seawater and drinking water? Dissolved substances like sodium chloride (table salt) make seawater salty . http://www.teachertube.com/viewVideo.php?title=Bill_Nye_Video&video_id=229775 4/18/2019

The Composition of Seawater What is salinity? Salinity is the total amount of solid material (or salt) dissolved in water The proportion of dissolved salt in seawater is very small, about 3.5% Most of the salt in seawater is sodium chloride, common table salt 4/18/2019

Salts in Seawater 4/18/2019

The Composition of Seawater Sources of Sea Salt? Erosion of rocks on the continents is one source of elements found in seawater 4/18/2019

What causes salinity of ocean water to increase or decrease? 4/18/2019 Increase salinity decrease salinity

Natural Processes Affecting Salinity 4/18/2019

Natural Processes Affecting Salinity Increase Salinity DECREASE WATER 1.Runoff of minerals from erosion of continents (adding salts to ocean) 2. Evaporation of sea water (especially at equator) 3. High Temperatures Decrease salinity ADD WATER Precipitation (add rainfall dilutes the salt) Melting icebergs and sea ice 4/18/2019

Ocean Density Variation Density = mass per unit volume It can be thought of as a measure of how heavy something is for its size Factors Affecting Seawater Density 1. Salinity (more salt vs. less salt) 2. Temperature (hot vs. cold) 4/18/2019

Factors Affecting Seawater Density Increase salinity = increase density Decrease temperature = increase density Question: Would seawater at the north pole be more or less dense than seawater at the equator? Answer : more dense Why? Cold water is denser than warm water 4/18/2019

Review 1. What is the source of dissolved salts in seawater? - weathering and erosion of minerals in rocks on continents 2. What factors affect the density of ocean water? - Temperature & Salinity 4/18/2019

Review 3. What is salinity? 4. What is the salinity of seawater? The total amount of dissolved material in water 4. What is the salinity of seawater? 3.5% or 35 parts per thousand 5. What are the two most abundant elements in seawater? Sodium and Chlorine, sodium chloride 4/18/2019