April 1st lecture FINAL EXAM IS WORTH 40%
Professor goes by Abhi (Obi) like star wars
One required textbook Earthquakes science and society
lecture will be on additional material not in book but will be guided by materials in the book. take notes (HE SAID IT ALOT!)
his lecture slides will not be posted.
CH.1 for this lecture
Why Learn Earthquakes?
they are not static they always move.
they are moving in a limited space
it will cause friction when it moves
moves very slowly a few centimeters a year.
slides past each other and radiated seismic energy. as it travels it causes shaking. seismic waves from epicenter cause a lot of shaking
pangea moved and separated into different continents.
the plate moved 400 km past each other creating 8.2 earthquake he shows a lot of examples of massive earthquakes.
Myths and legends
Thousands of years ago it was believed animals caused earthquake
believed that the earth was on a back of a big frog and when it moves so does earth.
catfish was the reason behind earthquakes when it shakes
japanese gods were in charge of taming the catfish.
Greek God: poseidon
he is short tempered and when he gets mad he stomps his foot causes earthquakes.
cyclical massive earthquake causing the end of the world.
they believe the earth on a snake, turtle and elephants when they moved the earth shaked. Tremor in Hollywood
movie about raboids causing an earthquake
Logic (Elastic rebound theory)
noticed that the land moved as the ground shook
Our Place in Earthquake Country
The goal is to be prepared for an upcoming earthquake by understanding it better.
Plate Tectonics (Read Chapter 6)
Sea Floor spreading
lithosphere- Solid is very hard. if you apply pressure it breaks (rock) Asthenosphere- solid but not as hard as lithosphere.(soft plastic) if you apply pressure it flows.
Mesosphere- “stiff plastic” he said we wont go over this too much in this class.
outer core- Liquid. It can flow. Acts as a dynamic for Earth’s magnetic field. Remember that. Made up of Iron and Metal. very dense liquid.
Inner core- Solid because the pressure is high. Pressure increases with increasing depth.
the lower you get the more dense the material becomes.
the lithosphere can flow on top of the asthenosphere which is very important to know when it comes of earthquakes.
Plate tectonics (what is it)
the placement of volcanoes and earthquakes are directly linked there is a pattern.
there is more in the middle east and volcanoes are in the same locations as earthquakes.
the boundaries from the plates above are creating volcanoes and earthquakes.
we know that plates move because plumes (molten rock) under volcanoes that want to come up stays in the same place over geologic time. so based on the plume we can find out how fast plate tectonics are moving. the closest volcano to the plume is the youngest volcano.
Plate tectonics Continental drift
the continents are like a jigsaw puzzle- you also see similar rock types in south america and africa. seeing the same plants and animal fossils suggests that the continents drifted away from each other previously being connected. the continents are in a very different configuration along time ago and if put in the right position they fit together. Think Pangea.
Ill look for an explanation later- don't feel like taking good notes lol Sea floor spreading
conveyor belt theory.
earths magnetic field- every few million years the magnetic field swaps so north and south will switch. magnetic reversals. rocks also show the reverse in the magnetic field. rocks are polarized in a normal position right now the last...
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