Chapter 1 Flashcards
Geology
Geology
Planetary Science
Geological Record
A standard time scale that partitions the Earth’s history into 4 eons and their subdivisions of eras, periods, and epochs
Information preserved in the rocks that have been formed at various times throughout Earth’s history.
Principle of Uniformitarianism
A principle stating that the processes we see in action on Earth today have worked the same way throughout the geological past.
1800’s - James Hutton
Geodesy
The science of measuring the shape of Earth and locating points on its surface.
Earth’s Radius
6370 km
Topography
The general configuration of varying heights that gives shape to earth’s surface, which measured with respect to sea level. The arrangement of the natural and artificial physical features of an area.
Eratosthenes’s
First to calculate Earth’s circumference (40 000 km). Using the angle in which the sun reflects on the surface of the Earth , he was able to calculate the distance around the equator.
Earth’s Circumference
40 075 km
Seismic Waves
An electric wave in the Earth produced by an earthquake or other means.
P-waves - Longitudinal
One of the two main types of elastic body waves, called seismic waves in seismology. P-waves travel faster than other seismic waves and hence are the first signal from an earthquake to arrive at any affected location or at a seismograph. P-waves may be transmitted through gases, liquids, or solids.
S-waves - Transverse
S wave, or secondary wave, is a wave motion in a solid medium where the medium moves perpendicular to the direction of the travel of the wave.
Earth’s Layers (Mass)
Crust (0-40 km) - 0.4% of Earth’s Mass
Mantle (40-2890 km) - 67.1% of Earth’s Mass
Outer Core (2890-5150 km) - 30.8% of Earth’s Mass
Inner Core (5150-6370 km) - 1.7% of Earth’s Mass
Crust
Thin outer layer of Earth, averaging 8 km (under ocean) and 40 km (under continents).
Oxygen (46%), Calcium (2.4%), Magnesium (4%), Silicon (28%), Aluminum (8%), Iron (6%), and other (6%).
Mantle
The main bulk of the Earth, between crust and core.
Oxygen (44%), Calcium (2.5%), Magnesium (22.8%), Silicon (21%), Aluminum (8%), and Iron (6.3%).
Core
The dense central part of Earth below the core-mantle boundary.
Outer Core
The Layer of the Earth extended from the core-mantle boundary to the inner core (2890 - 5150 km). Molten liquid.
Oxygen (5%), Sulfur (5%), Iron (85%), and Nickle (5%)
Inner Core
Central part of Earth consisting of a solid sphere suspended within the liquid outer core (depth of 5150 km)
Iron (94%) and Nickle (6%)
Mohorovicic Discontinuity (MOHO)
Moho is recognized as the boundary zone between the Earth’s crust and the mantle (think of the crust as layers).
Closed Systems
(heat energy) One where a series of quantities cannot enter or leave the system.
Open Systems
(solar energy) One where a quantity or series of quantities can enter or leave the system to a significant degree.
Climate system
The climate system is the highly complex system consisting of five major components: the atmosphere, the hydrosphere, the cryosphere, the lithosphere and the biosphere, and the interactions between them. The interactions among these components are needed to determine climate on a global scale and how it changes over time.
Climate
The average conditions of Earth’s surface environment and their variations.
Plate Tectonics
The lithosphere is not a continuous shell, it is broken into about a dozen large plates that move over Earth’s surface. Each lithospheric plate is a rigid unit that rides on the asthenosphere.
Lithosphere
The strong, rigid outer shell of the Earth that comprises of the crust and the upper mantle (Greek: lithos, meaning stone)
Asthenosphere
The upper layer of the earth’s mantle, below the lithosphere, in which there is relatively low resistance to plastic flow and convection is thought to occur (Greek: asthenes, meaning weak).
Convection
The mechanical transfer of heat energy that occurs as a heated material expands, rises, and displaces cooler material. Circulating the cooler material down to be reheated again in a circular motion.
Magnetic field
The region of influence of a magnetized body or an electric current. Interactions that produce a magnetic field.
Geodynamo
The process responsible for maintaining the Earth’s magnetic field in which the kinetic energy of convective motion of the Earth’s liquid core is converted into magnetic energy.
Hadeah
4560 MA - Earth Forms
4510 MA - Moon
4470 MA - Oldest lunar rocks
4000 MA - Oldest continental rocks
Archean
3800 MA - Evidence of water erosion
3500 MA - Record of magnetic field / Fossils of primitive bacteria
2700 MA - Start to the rise of atmospheric oxygen
2500 MA - Major phase of continent formation completed
Proterozoic
542 MA -
Phanerozonic
542 MA - Big Bang 420 MA - Earliest land animals 125 MA - Flowering Plants 5 MA - First hominids .2 MA - Homosapiens