Sept 2 Lecture (intro) Flashcards
list 4 risks on earth related to environmental geology
- earthquakes
- volcanoes
- floods
- landslides
How do humans add to the risks on earth? (list 4-7)
- soil erosion
- pollution
- shortage of clean water
- storage of toxic wastes
- fracking (man-made eq)
- oil/mineral extraction
- climate change
geology was an ____ science and now it’s an ____ science
observational –> analytical
list 3 problems with studying geology
- size (volcano is massive, river can’t be contained in a lab, etc)
- time (geological processes take millions of years, we’re limited to human time)
- resolution of data
- public wants predictions w/ exact time etc
define Anthropocene
humans now influence the earth, not the other way around (because there are so many people; exponentially growing)
did the solar system form before or after the universe?
after
the earth is at ___ degree tilt from vertical, which is why _________
23.5
days aren’t always the same length
list the planets of our solar system in order
mercury, venus, earth, mars, jupiter, saturn, uranus, neptune, pluto
- 4 rocky/ metallic, hot inner planets
- 4 gaseous, cold outer planets
the density/ composition of planets is correlated with how close they are to the ____
sun (temp they formed at)
describe how a gaseous planet could form
when a young star is surrounded by the dense disk of gas and dust, gaseous planets like Saturn can form. Once the gas has been ejected from the system, gaseous planets can no longer form
define panspermia
the theory that life on earth originated from microorganisms or chemical precursors of life present in outer space and able to initiate life upon reaching a suitable enviro like earth
earth earth was barren and lacked ___ and ____
oceans and atmosphere
earth was the target of many impacts. list 3
- asteroids (origin of moon!)
- meteorites
- comets (panspermia?)
differentiation of the earth developed _______ zones
compositional
list the 3 compositional zones of earth
- central core
- mantle
- crust
define the central core
dense and hot (made of nickel and iron)
define the mantle
thick zone that surrounds the core. composed of ultramafic and mafic rocks and magma (heat from core escapes by convective circulation)
crust of earth…
chemically different from core or mantle!
- 2 types= oceanic (mafic) and crustal (felsic)
how old is the earth predicted to be (right now)?
4.5-4.6 billion years old
how old did ussher predict the earth to be?
6000 years (in 1650) - predicted by counting the generations in the bible
how old did buffon predict the earth to be?
75000 years old (in ~1750)
- looked at mountain building rates
How old did Lyell predict the earth to be?
several hundred million years old (in ~1850)
- looked at uniformitarian- the forces molding the planet today have operated continuously throughout history; cooling rates)
How old did Kelvin predict the earth to be?
24-400 million yrs old (in ~1900)
- based off of thermal gradient calculations
how old did Joly predict the earth to be?
100 million years old in ~1900
- salt content of oceans
