MID TERM REVIEW Big Idea 1 Earth Scientists

MID TERM REVIEW Big Idea #1: Earth Scientists use repeatable observations and testable ideas to understand explain our planet Big Idea #2: Earth is a Water Planet

BIG IDEA #1: Earth Scientists use repeatable observations and testable ideas to understand explain our planet.

ENERGY THAT DRIVES EARTH’S 4 SYSTEMS WHAT’S THE CONNECTION?

HOW DO SCIENTISTS THINK? Critical thinking Strong Observations Extensive Documentation Collaboration

CREDIBLE ONLINE SOURCES

DATA VS EVIDENCE TURN DATA INTO EVIDENCE factual information as measurements or statistics used as a basis for reasoning • something that furnishes proof • something submitted to ascertain the truth of a matter.

TYPES OF DATA Qualities VS Quantity

• Direct SHOW ME THE EVIDENCE • Indirect • Modeling

HOW DO WE KNOW EARTH HAD AN ICE AGE?

EVIDENCE: DIRECT & INDIRECT Earth’s interior Direct Evidence: Rock Samples Indirect Evidence : Seismic Waves

SCIENTIFIC MODELS EXPLAINS SCIENTIFIC CONCEPTS Accurate & Inaccurate

BIG IDEA #2 Earth is a Water Planet

WHY IS THIS IMPORTANT? WHAT IS THE CONNECTION?

LETS TALK H 2 O VOCAB Surface Tension n o i t na i l a s e D Salinity Density F Solvent Spec ormula Capillary Action ific H eat

THE SCIENCE OF WATER’S 7 -UNUSUAL PROPERTIES 1. Stronger than normal bonds 2. High Surface Tension 3. High Boiling Temperatures 4. High Specific Heat 5. Universal Solvent 6. Density of the solid is less than at a liquid state 7. Adhesion, Cohesion, Capillary Action

FORMING A WATER MOLECULE Unequal attraction to bonding 16 electrons Oxygen is a strong electron grabber (high electronegativity) Hydrogen’s electron tends to hang out close to oxygen, leaving H’s positively charged O+ O+ + H- – +

WATER IS A POLAR MOLECULE Unequal distribution of charges on the water molecule make it a polar molecule One end is more negative, and one end is more positive More positive ends More negative end + means partial negative charge means partial positive charge

ELECTRON DENSITY IS UNEVEN Source: http: //www. llnl. gov/str/October 05/Mundy. html 18 The electron density around the oxygen atom in a water molecule is about 10 X greater than the hydrogen atoms This non-uniform distribution of positive and negative charges, called a dipole, leads to H 2 O unusual Dark Blue= high density behavior Light Blue= low density

UNUSUAL PROPERTIES

LETS TALK OCEAN

WHERE DOES THE SALT COME FROM?

WHAT INCREASES & DECREASES SALINITY?

1. OCEAN LAYERS FROM THE SHORE

1. OCEAN LAYERS DEPTH: 3 -ZONES

2. OCEAN VARIATIONS Temperature: Thermocline Density: Pycnocline

WATER ON A GLOBAL PERSPECTIVE= UNEQUAL HEATING Longitude Latitude

3. OCEAN CURRENTS What drives them? How do they form? Effect of cold currents on climate? What is the role in maintaining Earth’s heat balance? 2 -Types: Density currents Deep ocean currents

4. WAVES TRANSFERS ENERGY FROM ONE POINT TO ANOTHER

5. TIDES DAILY CHANGES IN THE ELEVATION OF THE OCEAN SURFACE