Climate Change 14.3 Essential Question: How does the ocean and the atmosphere work together to influence global climates? Big Idea: The atmosphere and the oceans are directly linked to one another. Working together they shape the world’s current climate and produce the variations we experience form year to year.

 Short Term Climate Changes:  a temporary shift in climate  May last a few months or a few years before returning back to the original climate conditions  Example: Seasons and El Nino/La Nina  El Nino/La Nina: A shift in the water temperatures along the equatorial Pacific  Caused by a change in strength of the Trade Winds  The trade winds blow from east to west towards the equator Climate Change 14.3

Normal Conditions:  No influence from El Nino or La NIna  Cool water flows along the west coast of South America coming up from Antarctica  Trades winds and ocean currents keep water warm along the east coast of Australia/Indonesia  Surface waters along the west coast of South America are pushed away from the coastline, and cold nutrient-rich water from below comes up to replace it. This is called upwelling and is vital to marine life and fishing communities. Climate Change 14.3

Cool waters in Eastern Pacific Warm waters in Western Pacific

El Nino:  Trade winds loose strength  Allows warm water from the western pacific to move east toward S. America  Strengthens convection currents near South America  Adds heat and moisture to the  upper atmosphere  Upwelling is decreased or ceases. (This is bad) Climate Change 14.3

El Nino Climate Changes:  violent storms in California and Gulf Coast  stormy weather moves eastward where it is normally dry  drought condition to normally wet areas  Weaker Atlantic Hurricanes  stronger winter storms in our area Climate Change 14.3

La Nina: The opposite of El Nino  Stronger than normal Trade Winds  Creates cooler than normal water temperatures in the equatorial Pacific  Upwelling is stronger than usual La Nina Climate Changes:  Warmer winter temperature in Eastern US  Stronger Atlantic Hurricanes

Oceanography Chapters 15 & 16 Essential Questions: What are the features of the ocean floor? What are the chemical and physical properties of ocean water? How do waves and currents form? How do the oceans influence human activities and the environment?

Chapter 15 Earth’s Oceans Big Idea: Studying oceans helps scientists learn about global climates.

 Main Idea: The global ocean consists of one vast body of water that covers more than two-thirds of Earth’s surface An Overview of the Oceans

 Methods for Studying the World’s Oceans 1. Challenger -1 st ship in 1800’s to study the oceans 15.1 An Overview of the Oceans Challenger’s Journey

2. SONAR-SOund Navigation And Ranging  first used by submarines during World War I  Sound waves are sent outwards from the bottom of the vessel  They hit the ocean floor and bounce back up to the boat  The time it takes for this to happen (divided by 2) gives us the ocean depth 15.1 Overview of the Oceans

3. Alvin – submersible that travels to the bottom of the ocean (up to 4500 meters deep)  First deep sea submersible capable of carrying passengers 15.1 An overview of the Oceans

Origin of the Oceans  There are two leading theories 1 st Hypothesis:  Comets and meteorites carried water to early earth pounded early Earth when Earth was still largely molten on the surface  they contain about 0.5% water  Water collected to form the oceans 15.1 An Overview of the Oceans

2 nd Hypothesis  volcanism brought water up to the surface from inside the Earth via eruptions  volcanoes release water vapor, carbon dioxide, and other gases that make up the atmosphere  The water vapor condensed, fell to the ground as rain and collected in the ocean basins 15.1 An Overview of the Oceans

The Distribution of water on Earth  97% of water on Earth is salt water and is found in the oceans  3% of water on Earth is freshwater found in :  Icecaps, Groundwater, Rivers, Lakes  The Earth’s oceans cover 71% of Earth’s surface 15.1 An Overview of the Oceans Interesting Fact: The average depth of the ocean is 4 times greater than the average elevation of the continents, but if the Earth were to be shrunk to the size of a globe, it would be difficult to "feel" that the oceans are wet, the deepest part would be as thin as a few sheets of paper. Interesting Fact: The average depth of the ocean is 4 times greater than the average elevation of the continents, but if the Earth were to be shrunk to the size of a globe, it would be difficult to "feel" that the oceans are wet, the deepest part would be as thin as a few sheets of paper.

15.2 Seawater Main Idea: Oceans have distinct layers of water that are characterized by temperature and salinity.

 When comparing ocean water to water on the rest of our planet, it has dramatically different properties all due to its salt content  Salinity = amount of dissolved salts in seawater  Measured in ppt – parts per thousand  Average salinity of seawater = 35ppt OR 35‰ 15.2 Seawater

Subtropical Regions  evaporation rate is high = Salinity - 37 ppt Equatorial regions  precipitation rate is high = Salinity - 32 ppt  Estuaries – where large rivers empty into the oceans = Salinity varies with the tidal cycle 15.2 Seawater

The salt comes from:  Volcanoes  the sulfur dioxide and chlorine gasses released from the volcanoes  Weathering and Erosion  sediments containing various minerals enters the oceans and creates the salt  These sediments enter the oceans through run-off and river systems Seawater

 Removal of salt  Formation of evaporites  Marine organisms remove salt to build shells, bones, and teeth  Wind – sea spray The Salt Cycle

 The Ocean’s Salinity alter its physical properties when compared to freshwater  Density : 1.02 g/cm 3 to 1.03 g/cm 3 More salt = more dense 15.2 Seawater What other property could produce a change in density? Temperature: Cold temps = Higher Density Temperature: Cold temps = Higher Density Freezing Point: -2°C or 28°F It is lower than fresh water because of the salt The water near the poles hovers at -2 o C Water near the equator is around 30 o C

 Light Absorption: light only penetrates the top 100m  Red light – does not penetrate past 10m  Blue light – travels about 250m  Top 100m – Photic Zone  Below 100m – Aphotic Zone 15.2 Seawater

 The vertical layering of the ocean is determined by temperature  the deeper you go the colder it gets  However, the dark part of the ocean has a fairly consistent temperature  Thermocline = temperature decreases rapidly with depth 15.2 Seawater

The vertical layering of the ocean does not look the same everywhere The temperature of the surface water changes the way it looks

 Deepwater masses move from the North and South poles to the equator  As sea ice is formed, the oceans become saltier  Salty, cold water sinks below the sea ice and travels to the poles 15.2 Seawater

15.3 Ocean Movements MAIN IDEA: Waves and currents drive the movements of ocean water and lead to the distribution of heat, salt, and nutrients from one region of the ocean to another.

Wave =  a rhythmic motion/movement that carries energy through space or matter  Ocean waves are caused by wind blowing over water  Energy moves forward, but water moves in a circular pattern 15.3 Ocean Movement

 As waves move into shallow waters, breakers form, as the water encounters friction on the sea floor.  Friction causes the bottom of the wave to slow down and the top of the wave crashes over 15.3 Ocean Movements

 REVIEW:  What controls the tides??  Make sure you review tides from when we learned them in Astronomy 15.3 Ocean Movements

Surface Currents  The top 100 m -200 m  Move about 100 km per day  Global wind systems push the surface currents  Example: The Gulf Stream runs along the East coast of the US  It brings warm water from the south up the coast and across the N. Atlantic  This is why England experiences mild temperature s all year even though it is located very far north of the equator 15.3 Ocean Movements

 Gyres  Circular surface currents created by the interaction of surface currents and major land masses  Circulation is influenced by the Coriolis Effect  - Northern Hemisphere – clockwise  - Southern Hemisphere - counterclockwise 15.3 Ocean Movements

Density Currents  Caused by differences in the temperature and salinity  Cold water at the poles sinks and moves toward the equator  May take 1000 years for one density current to complete a cycle 15.3 Ocean Movements

Upwellings:  the vertical, upwards movement of ocean water  They originate below the thermocline – would these currents be cold or warm?  The carry with them the rich nutrients that settle at the ocean bottom  Most upwelling are along the western coasts of the continents with in the trade winds Ocean Movement

Chapter 16 The Marine Environment

16.1 Shoreline Features MAIN IDEA: The constant erosion of the shoreline and deposition of sediments by ocean waves creates a changing coastline.

 Shore = area of land between water level at low tide and water level during intense storms; shaped by waves, tides, and currents  Beach = area in which sediment is deposited  Large sand grains = formed by large waves  Small sand grains = formed by small waves  The composition of the sand varies depending on where its located 16.1 Shoreline Features

Why do you think the sand is black in parts of Hawaii?? The Basaltic Volcanos!! Where else in the US could we have black sand? Black Sand Black sand will only happen near more active volcanoes White Sand is found in the Southeastern United States The sand in the northeast is composed mainly of quartz Has more of a tan color to it

 Erosional Features:  created by the erosional force of the waves  wave cut cliffs  wave cut platform  Sea Stacks 16.1 Shoreline Features

Formation of Sea Caves, Arches and Stacks

 Depositional Features:  The sediments collect from wave erosion are deposited on the shore line  Spit  Barrier Islands  Baymouth Bars  Tombolo 16.1 Shoreline Features

 Depositional features are created largely by the longshore current  The sediments are carried along the shoreline via the longshore current 16.1 Shoreline Features

Longshore Drift

16.2 Seafloor Features MAIN IDEA: The ocean floor contains features similar to those on land and is covered with sediments of several origins.

Continental Margin:  Where the edges of the continents are submerged under the ocean  Continental Shelf = shallow, gentle sloping area near coastlines  Continental Slope = steep, marks edge of continental crust - on the slope deep cuts form called submarine canyons - these canyons are cut out by turbidity currents - rapidly flowing water currents along the bottom of the ocean carrying heavy sediment loads  Continental Rise = sediments getting piled up from turbidity currents 16.2 Seafloor Features

 Abyssal Plain = flattest part of ocean floor  5-6km below sea level  Deep-sea Trenches – elongated depression in the seafloor several kilometers deeper that the abyssal plains  Form when plates collide and one subducts  the deepest parts of the ocean  Marians Trench - 11,033 meters deep 16.2 Seafloor Features

 Mid-Ocean Ridge = underwater mountain range  Seamount = submerged basaltic volcanoes  Guyot= an extinct underwater volcano with a flat top 16.2 Seafloor Features

Ocean Floor Sediment: Three main groups: 1) Terrigenous: sediments dispersed by ocean currents consisting of fine silt, clay, and volcanic ash  Examples: Muds and clays Turbidites (landslide on the ocean floor) 16.2 Seafloor Features

2) Biogenous- sediments created by biologic activities Examples:  Oozes - sediments made form microscopic shells (forams [CaCO 3 ] and diatoms [SiO 2 ]) Seafloor Features And…….. A whole lot of fish poop!

3) Hydrogenous – sediments derived from elements in the seawater Examples: Manganese nodules – when magnesium, iron, and copper precipitate out to the water 16.2 Seafloor Features

 The ocean floor is basaltic rocks  The different density between granitic continents and basaltic oceanic rocks is why we have oceans. Felsic (granitic) rocks "float" up and mafic (basaltic) rocks "sit" lower Seafloor Features What is the name of the rock that makes up the ocean floor? What about the continents? What is the name of the rock that makes up the ocean floor? What about the continents?