Geology: the study of the earth
Both present and past: news and history
The vastness of scales (atomic particles to
Professional Uses
Civil Engineers, Landscape Architects, Artists
Citizen Uses
Climate Change, Hazards, Groundwater contamination
Humanistic Uses
Appreciation for the environment, Understanding our place
Stuff that Makes Up the Universe
Element = Matter that cannot ordinarily be broken down
Atom = Smallest particles that retain properties
Atom = protons + neutrons + electrons
Atomic number, Isotopes, Ions, Atomic weight
Radioactivity
Formation of the Sun
15 billion years ago: Big Bang
Only elements hydrogen and helium existed
Formation of clouds and stars by gravity
Nuclear fusion creates elements from Li to Fe
Stars explode ("supernova") creating elements heavier than Fe
4.6 billion years ago: Formation of the sun
Formation of Planet Earth
Earth starts out homogeneous but hot (radioactivity and friction)
Iron melts and sinks: Core
Gases vaporize and rise: Atmosphere and hydrosphere
Silicon and oxygen melt and rise: Crust
Leftovers (magnesium, silicon, and oxygen): Mantle
The Earth’s Interior
Crust: 7 to 70 km thick
Mantle: to 3100 km down
Core: Inner and outer cores
Lithosphere: 100 to 350 km thick
Asthenosphere
Plate Tectonics: the Revolutionary Theory
Lithosphere is broken into about a dozen pieces
Plates move between 1 and 10 cm per year
Most geologic activity occurs at boundaries
Hotspots
Plate boundaries
Convergent: subduction and continental collision
Subduction is the driving force
Divergent: rifts and mid-ocean ridges
Transform