Topic 1 introcosmology

Webster’s Definition:Main Entry: ge·ol·o·gy Function: noun Etymology: New Latin geologia, from ge- + -logia -logy Date: 1735 1 a : a science that deals with the history of the earth and

Geology 101 - Physical Geology

Dr Arlo Weil

Webster’s Definition:

Main Entry: ge·ol·o·gy Function: noun

Etymology: New Latin geologia, from ge- + -logia -logy

Date: 1735

1 a : a science that deals with the

history of the earth and its life especially as recorded in rocks

••Climate Change Climate Change

••Petroleum, Minerals, and Metals Petroleum, Minerals, and Metals

••Sustainable Natural Resources Sustainable Natural Resources

E t d th E i th E i t t

••Ecosystems and Ecosystems and the Environment the Environment

••Natural Hazards, Natural Hazards, Disasters, & Mitigation Disasters, & Mitigation g

••Civil Engineering Civil Engineering

••Public Planning & Public Planning & Policy Policy

••Public Planning & Public Planning & Policy Policy

••Education Education

Status of the Geoscience Workforce

Oil & Gas Industry Demand for Geoscientists

Source: AGI Geoscience Workf orce Program

Percentage of Geoscience Degrees Conferred to Women

Atmosphere and Oceans

River (Fluvial) Systems

Earth’s place in the

Earth’s place in the

Retrograde Planetary Motion

The Ptolemy Model

Heliocentric Universe

Heliocentric Universe Concept Concept

Retrograde Planetary Motion

The Copernicus Model (~1500 A.D.)

Planetary Motion

Phases of Venus

Phases of Venus Galileo Galileo

Moons of Jupiter Galileo Galileo

Eratosthenes (c 276-194 B.C.)

Determining the dimensions of Earth

40,008 km ,

Distance from Alexandria to Syene was 4900 stadia, so ratio

Parallax

Parallax

Solar System – 8 planets + Pluto

Earth ~ 6.8 Ga People

Earth ~ 4.6 Ga

Milky Way ~ 100

Milky Way ~ 100 Ga Ga star clusters star clusters

Universe ~ 100’s of Ga galaxies

How did it all start???

Hubble & Humason

Expanding Universe

p 26-27a

Origin of Earth

p 26-27a

Modified Nebular Hypothesis

p 26-27a

Gravitational Attraction

Angular Momentum

Angular Momentum

L  mvr

Pressure Temperature

Proto-solar systems ~ Hubble Images

Planetesimals

Bode’s Law

Planetesimals meteorites meteorites

Asteroid Belt

Asteroid Belt

Ceres

Inner Planets

• Terrestrial planets

• Small rocky bodies very little

volatiles

• Silicates and metals (Fe, Ni)

• Solidified at high temperatures

• Early differentiation - Metallic cores, Mantle and Crust

• Later developed atmospheres

of volatile gases

Outer Planets

• “Gaseous Giants”

Jupiter Saturn Uranus Neptune Pluto

• Lack solid surface

• Volatile rich (H, He, O) – similar to constituents of original nebula

• Low temperature solidification

• Thin, flat rings Thin, flat rings

• Highlands – bright densely cratered region…~4 Ga g

• Highlands – bright densely cratered region…~4 Ga g

• Highlands – bright densely cratered region…~4 Ga g

Classification of Earth’s major Layers

Classification of Earth’s major Layers

Magnetic Field

•• Dipolar Dipolar magnetic field magnetic field.

•• Magnetic field lines flow from N to S and… Magnetic field lines flow from N to S and…

–– Extend into space and weaken with distance from Earth Extend into space and weaken with distance from Earth –– Create a shield around Earth (the magnetosphere) Create a shield around Earth (the magnetosphere).

The Earth’s Surface