Transcript Slide 1
The Sources of the Ocean’s Salts Amanda Hauser and Alexa winters Sources of Ocean’s Salts • Weathering and erosion of crustal rocks – Dissolving action of rains and streams bring minerals to the ocean • Upper mantle contains more substances found in seawater than are found in surface rocks Sources of Ocean’s Salts • Outgassing through volcanoes and rift vents • Differences in expected seawater concentrations may result at mid ocean rift interactions • Water in the ocean is thought to cycle through the seabed at rift zones every 1 to10 million years Ions Changing Water Mike M and Stefan K • The ions in seawater react with each other and water molecules. • They modify the properties of water, thus allowing the water to have different qualities. • Some Examples of water being changed are… – Compared to fresh water, seawater(because of it’s salinity) has a lower heat capacity. – Salinity also allows water’s freezing point to become lower. – The salt in seawater attracts more molecules which makes seawater evaporate slower than fresh water. Make up of seawater The Principle of Constant Proportion: •Term and principle coined by Joseph Proust . •Meant that no matter the difference in mass between two or more liquids, and the difference of the sources of said liquids, the percent of chemicals in the liquids would be the same. •For example, a beaker containing 31 grams of water from the middle of the ocean would have the same percentage of oxygen and hydrogen in it as a beaker containing 8 grams of water from a storm drain. •The proportion remains constant. Claire Edelman & Max Cohen 11/19/14 1A Chemical Equilibrium • Dissolution of gases in the ocean takes a relatively long time to come to equilibrium. Mixing gas and liquid at the surface is inefficient, even with wind agitating the liquid surface. Mixing of the upper layers of the ocean with the next lower layers takes many years, as exemplified by energy transfer in the top layers, and movement of surface layers to the deep ocean takes centuries. Thus, some of the CO2 from fossil fuel combustion dissolves in the top layers of the ocean in a few years, while some of the rest requires centuries or millennia to come to solubility equilibrium with the entire ocean. This equilibrium is temperature sensitive. For example, during a glacial period, the system has many thousands of years to reach equilibrium at a low ocean temperature. As the ocean temperature increases at the beginning of an interglacial period, the equilibrium shifts to the left. CO2 becomes less soluble, its atmospheric concentration increases, and it contributes to further warming via its greenhouse effect. The chemical from the Atmosphere from the chemicals in the air and in the ocean they can become unbalanced. Gases in Seawater Jared Wallace & Zach Ponte Nitrogen • The element nitrogen is a nonmetal founded in 1772 by Scottish physician Daniel Rutherford. • It makes up about 78% of air and about 62% of water • Nitrogen is an essential nutrient required in the production of organic matter by marine plants. Oxygen • Oxygen is a non-metal that was founded in 1774 by Joseph Priestly and Carl Scheele • It makes up about 21% of air and about 34% of water • It is produced in the ocean as a result of photosynthesis performed by phytoplankton, seaweed, and other types of algae. • Carbon Dioxide Carbon Dioxide is composed of two oxygen atoms and one carbon atom and was originally discovered in the seventeenth century by chemist Jan Baptist van Helmont. • It is found in less that one percent of air and about 1.4% ofwater. It is used by algae in photosynthesis to produce oxygen for other organisms.