Chapter 1: The Earth System Flashcards
asthenosphere
The weak layer of soft but solid rock comprising the lower part of the upper mantle (below the lithosphere) and over which the plates slide. Movement in the asthenosphere occurs by plastic deformation.
climate system
A geosystem that includes all parts of the Earth system and all the interactions among these components needed to describe how climate behaves in space and time.
core
The central part of the Earth below a depth of 2900 km, comprising a liquid outer core and a solid inner core.
crust
The thin outer layer of the Earth, averaging about 8 km thick under the oceans to about 40 km thick under the continents, consisting of relatively light materials that melt at low temperatures.
Earth system
All the parts of our planet and all their interactions, taken together. The collection of Earth’s open, interacting, and often overlapping geosystems.
fossil
Trace of an organism of past geologic ages that has been preserved in the crust.
geodynamo
The global geosystem that sustains Earth’s magnetic field, driven by convection in the outer core.
geosystem
A specialized subsystem of the Earth system that encompasses specific types of terrestrial behavior/geologic activity.
inner core
The central part of the Earth from a depth of 5150 to 6370 km, composed of iron and nickel. A solid metallic sphere with a radius of 1220 km suspended within the liquid outer core.
lithosphere
The strong, rigid outer shell of the Earth that encases the asthenosphere and contains the crust and the uppermost part of the mantle down to an average depth of about 100 km and forms the rigid plates.
magnetic field
The region of influence of a magnetized body or an electric current.
mantle
The region that forms the main bulk of the solid Earth, between the crust and the core, ranging from depths of about 40 km to 2900 km.
outer core
A liquid zone composed of iron, nickel, and minor amounts of some lighter element, such as oxygen or sulfur below the mantle, from a depth of 2890 to 5190 km, that surrounds a solid iron-nickel inner core.
plate tectonic system
A geosystem that includes all parts of the Earth system and all the interactions among these components needed to describe how plate tectonics works in space and time. Includes the convecting mantle and its overlying mosaic of lithospheric plates.
principle of uniformitarianism
The principle that the geologic processes we see in action today have worked in much the same way throughout geologic time; that is, the present is the key to the past.
scientific method
A general research plan, based on methodical observations and experiments, by which scientists propose and test hypotheses that explain some aspect of how the universe works.
seismic wave
A ground vibration produced by earthquakes or explosions.
topography
The general configuration of varying heights that gives shape to Earth’s surface.
climate
The average conditions of Earth’s surface environment and their variation
convection
The mechanical transfer of heat energy that occurs as a heated material expands, rises, and displaces cooler material, which is itself heated and rises to continue the cycle.
geodesy
The science of measuring the shape of Earth and locating points on its surface.
geologic record
Information about geologic events and processes that has been preserved in rocks as they have formed at various times throughout Earth’s history.
geology
The branch of Earth science that studies all aspects of the planet: its history, its composition and internal structure, and its surface features.
nebular hypothesis
Explains the formation of the solar system
differentiation
The process by which an originally homogeneous Earth developed a dense core and a light crust
Vallis Marineris
The longest and deepest canyon in the solar system
Mohs Hardness Scale
1 Talc 2 Gypsum/Selenite 3 Calcite 4 Fluorite 5 Apatite 6 Orthoclase Feldspar/Microcline 7 Quartz 8 Topaz 9 Corundum 10 Diamond
geophysics
A branch of science that deals with the physical movements and forces of the Earth (such as its climate and oceans)
Emil Wiechert
Looked to meteorites for why the earth was so dense
Robert Oldham
Sorted out the paths of the two types of waves (P&S)
Beno Gutenberg
Confirmed the core-mantle boundary
Mohorovicic
Found the boundary between the crust and mantle
Inge Lehmann
Confirmed the existence of the inner and outer cores
isostasy
A principle stating that the buoyancy force that pushes upward a lower-density body (continent) floating in a higher-density medium (asthenosphere) must be balanced by the gravitational force that pulls it downward.
