Early Earth: I. Ch 12, Sec 1 -

Early Earth: I. Ch 12, Sec 1 -

Early Earth: I. Ch 12, Sec 1 - Is Earth Unique? I. Ch 12, Sec 1 - Is Earth Unique? A. The Right Planet

1) If Earth was much larger, it would have more gravity and a thick, nasty atmosphere of lighter gases such as Ammonia, Methane, Hydrogen and Helium. I. Ch 12, Sec 1 - Is Earth Unique?

A. The Right Planet 2) If Earth was much smaller, it would have less gravity Oxygen and water vapor would escape into space and there would be no life on Earth! I. Ch 12, Sec 1 - Is Earth Unique?

A. The Right Planet 3) If Earth didnt have a plastic (gooey) layer of mantle below its rigid crust, there would be no plate tectonics, no continental crust and mountains. Earths entire surface would be fairly flat and completely covered by a shallow ocean.

I. Ch 12, Sec 1 - Is Earth Unique? The Right Location B. 1) If Earth was 10 % closer to the Sun, the extra heat would drive oxygen and

nitrogen into space, leaving behind mostly heavier carbon dioxide. Earth would be too hot and oxygen-poor for higher life forms to thrive. B. I. Ch 12, Sec 1 - Is Earth

Unique? The Right Location 2) If Earth was 10% farther away from the sun, it would be so cold that the ocean would freeze over. (No liquid water = no life.).

I. Ch 12, Sec 1 - Is Earth Unique? The Right Location B. 3) Our medium-sized sun has a nice long 10 billion year life span. If the Sun was a giant star, it would

burn hotter and burn out in just a few 100 million years. There would not have been enough time for any significant evolution to occur. I. Ch 12, Sec 1 - Is Earth Unique?

The Right Time C. 1) There has been enough time for the atmosphere to develop. The early atmosphere contained methane, ammonia, water vapor and carbon dioxide. There was

no free oxygen (O2). I. Ch 12, Sec 1 - Is Earth Unique? The Right Time C. 2) Photosynthetic bacteria released

O2 into the atmosphere. The appearance of O2 in the atmosphere made possible the evolution of higher organisms. I. Ch 12, Sec 1 - Is Earth Unique? The Right Time

C. 3) 65 mya Earth was struck be a 6 mile diameter asteroid, causing a mass extinction which killed off 75 % of all plant and animal life. I. Ch 12, Sec 1 - Is Earth

Unique? The Right Time C. 4) The extinction of the dinosaurs made possible the rise and diversification of mammals.

Proto-Earth: II. Ch 12, Sec 2 Birth of a Planet B. Earths Early Evolution. The first of a billion years of

Earths history (from 4.6 3.8 bya) is called the Hadean Eon: II. Ch 12, Sec 2 Birth of a Planet Proto-Earth was a chunky

dust ball which weighed much less than its present mass, but was much bigger across. II. Ch 12, Sec 2 Birth of a Planet

B. The sun was just warming up then, so proto-Earth was very chilly: - 347o F ( 347o below zero F ) ( 40o above absolute II. Ch 12, Sec 2 Birth of a

Planet C. Proto-Earth was heated up very quickly by: 1) Gravitational Compression 2) Intense Radioactivity (from minerals and elements inside the earth

II. Ch 12, Sec 2 Birth of a Planet C. Proto-Earth was heated up very quickly by: 3) Millions of Meteorite Impacts which terrorized the early solar system until about 3.9 billion years ago (bya)

METEORITE BOMBARDMENT Proto-Earth II. Ch 12, Sec 2 Birth of a Planet

4.6 bya 3.8 bya D. The intense meteorite bombardment and radioactive decay caused Earths crust to heat up and completely melt, resulting in a magma ocean (about 4.5

bya). II. Ch 12, Sec 2 Birth of a 4.6 - 4.5 bya Planet E.During this molten phase, the heavier metals Iron and Nickel sank to form an Ironrich core and a thick mantle

of iron-rich silicate rocks II. Ch 12, Sec 2 Birth of a Planet E.while the lower density (lighter) silicate rocks rose closer to the surface to form a thin primitive crust. This

major sorting-out event is known as the Iron II. Ch 12, Sec 2 Birth of a Planet Crystalline Iron Meteorite F. Although it was hotter, the

inner core solidified first, because the tremendously high pressures at the center allowed iron to crystallize and harden at 5000o C. That is Similar to Crystalline Found in Earths hotter than theIron

surface of Core II. Ch 12, Sec 2 Birth of a Planet G. 50 million years later, the outer 500 miles of the earth cooled and hardened into the crust and

upper mantle. Earths layering was completed 4.4 billion years ago (b.y.a.) 4 Layers of the Earth Crust Mantle

Liquid Outer Core Solid Inner Core II. Ch 22, Sec 2 Mars-Sized Planetesimal Impacts Earth 4.5 bya

II. Ch 22, Sec 2 to form the Moon II. Ch 22, Sec 2 to form the Moon

4.45 bya 3 Hypotheses on the Formation of the Solar System Remember: A 2 million mph solar wind and deadly U-V

radiation stripped away the gas layers of the 4 inner planets (theyre now rocky). III. Ch 12, Sec 3 Origin of the Atmosphere and Oceans

A. Earths original atmosphere was stripped away by an intense solar wind, so Earth has had to grow a new one! B. Earths early atmosphere contained Hydrogen (H), Helium (He), Methane (CH4), Ammonia, (NH3), Carbon dioxide (CO2) and

steam / water vapor (H2O). Early oceans III. Ch 12, Sec 3 Origin of the Atmosphere and Oceans C. Earth acquired its water from two main sources:

1) Earth was bombarded by icy planetesimals and comets from beyond Mars that vaporized when they struck Earth. Earths gravity kept the water from escaping. III. Ch 12, Sec 3 Origin of the Atmosphere and Oceans

C. Earth acquired its water from two main sources: 2) Worldwide volcanic eruptions released lava but also caused a lot of volcanic outgassing, releasing Carbon dioxide, Nitrogen and Sulfur oxides and a large amount of steam (boiling hot water vapor) into

III. Ch 12, Sec 3 Origin of the Atmosphere and Oceans Hot gases & Steam Volcan

o III. Ch 12, Sec 3 Volcanic Outgassing Hot gases & Steam

Volcan o III. Ch 12, Sec 3 Origin of the Atmosphere and Oceans D. The early atmosphere was 50 % water (H2O vapor) with a lot of CO2 & NO2:

1) The C from CO2 combined with H to make methane (CH4). 2) The N from NO2 combined with H to form ammonia (NH3). III. Ch 12, Sec 3 Origin of the Atmosphere and Oceans D. The early atmosphere was 50 %

water (H2O vapor) with a lot of CO2 & NO2: 3) Loose H and He atoms escaped into space because Earths gravity was too weak to hold on to these very light gases. III. Ch 12, Sec 3 Origin of the

Atmosphere and Oceans E. The steam caused thunderstorms which raged for centuries. III. Ch 12, Sec 3 Origin of the Atmosphere and Oceans F. Earths early ocean was a

relatively fresh-water sea. It took many more years of acid rain to wash enough Na and Cl out of the rocks and down the rivers to the oceans to make salt III. Ch 12, Sec 3 Origin of the Atmosphere and Oceans

G. Most importantly, there was no free oxygen (O2) in Earths atmosphere until 2.0 b.y.a., so early life forms were limited to those that didnt need oxygen (they were anaerobic). III. Ch 12, Sec 3 Origin of the

Atmosphere and Oceans H. Oxygen first appeared during the Great Oxygenation Event 2.4 by ago due to: 1) Photosynthetic bacteria esp. the blue green kind followed later by green algae and plants

Bacterial Stromatolites earliest photosynthetic bacteria Modern Stromatolites Sharks Bay, Australia Fossil Stromatolites Earths oldest fossils III. Ch 12, Sec 3 Origin of the

Atmosphere and Oceans H. Oxygen first appeared during the Great Oxygenation Event 2.4 by ago due to: 2) Splitting of water molecules in

the sky (electrolysis) by: lightning and Splitting of Water Molecules by Lightning and UV rays III. Ch 12, Sec 3 Origin of the Atmosphere and Oceans I. With the addition of oxygen

(O2), and the resulting ozone layer (O3), life on Earth really took off!

Recently Viewed Presentations

  • UK Education: Skills gaps and recruitment

    UK Education: Skills gaps and recruitment

    We start with GCSE which we call key stage 4 - generally for 14 to 16 year olds. ... For example purposes, the Certificate in Digital Applications (or CiDA) is 30 hours of learning about fundamentals (where about 15% is...
  • Priors, Normal Models, Computing Posteriors

    Priors, Normal Models, Computing Posteriors

    Why posteriors need to be computed. If you can find a conjugate prior for your data-parameter model, it's very sensible to use that and to coerce your prior into that form
  • Classroom Procedures and Expectations

    Classroom Procedures and Expectations

    Classroom Procedures and Expectations Mr. Hennessee Lexington Middle School WELCOME We're going to have a Wonderful year together. Have Positive Expectations!
  • Super History Hero

    Super History Hero

    You will be creating the packaging for a historical figure AS A SUPERHERO. Make the packaging colorful and eye-catching. You will work as an individual. You will provide biographical information that is historically accurate and detailed. Drawings can not be...
  • Collection 5- Worlds of Words: Prose and Poetry

    Collection 5- Worlds of Words: Prose and Poetry

    Exact rhymes- words rhyme exactly (may/day) Slant rhymes- their sounds almost rhyme but no exactly (milly and molly) Reading Assignment. Read "Maggie and milly and molly and may" pg. 599. After you read, complete worksheet and questions 2, 3 and...
  • Web Security - Stanford University

    Web Security - Stanford University

    Scope setting rules (write SOP) domain: any domain-suffix of URL-hostname, except TLD. example: host = "login.site.com" login.site.comcan set cookies for all of .site.combut not for another site or TLD
  • Principles of Anatomy and Physiology 14th Edition CHAPTER

    Principles of Anatomy and Physiology 14th Edition CHAPTER

    Location. Function. Appearance. Control. Skeletal [Insert skeletal muscle image from Table 10.5, pg. 321] Cardiac [Insert cardiac muscle image from Table 10.5,
  • CHAPTER 5: The Integumentary System

    CHAPTER 5: The Integumentary System

    Chapter 5: The Integumentary System ... Lunula ("moons") pale crescent at base of nail where underlying blood vessels may be obscured Structure of a Nail Figure 5-13 * Cutaneous membrane = epidermis + dermis Parts of the Integumentary System Cutaneous...