Vocab Flashcards
nebula
swirling cloud of dust and gas
supernova
star in a massive explosion
planetesimals
The formation of elements such as iron, nickel, silicon, calcium, sodium, and potassium, con- densed that are joined together to form small bodies
protoplanets
Are larger objects coalesced by attraction and turbulence in the swirling nebula, that cause collisions to occurred between the planetesimals
Accretion
the process of growth by the gradual accumulation of additional layers or matter
lunar rocks
rocks found on the Moon
outcrop
a rock formation that is visible on the surface
bedrock
solid rock underlying loose deposits such as soil or alluvium
geologic time scale
a Calendar, constructed from numerous observations and measurements in thousands of out- crops from all over the world
geologic time is divided into eons, eras, and periods
Eons
the longest sub- divisions of the time scale, some having lengths of billions of years
Just four, the Hadean, Archean, Proterozoic, and Phanerozoic eons, encompass all of Earth history
Phanerozoic Eon
takes in the last 541 million years, is subdivided into shorter time intervals lasting hundreds of millions of years called eras, of which there are three, the Paleozoic, Mesozoic, and Cenozoic
Eras
the last 541 million years, is subdivided into shorter time intervals lasting hundreds of millions of years
are three, the Paleozoic, Mesozoic, and Cenozoic
Periods
eras that are subdivided into still-shorter time intervals
lasting tens of millions of years
lithosphere
includes all of the crust and the upper portion of the mantle
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
convection
where material adjacent to a heat source is warmed, becomes less dense and rises, and cold material moves in to takes its place
The Flow of Heat
Earth loses more heat from its surface than it absorbs from the Sun. This is achieved by the flow of heat (known as heat flow) from Earth’s core to its surface, where the heat escapes.
This flow occurs by several mechanisms, the most important of which are conduction, convection, and radiation.
Conduction
primarily occurs in solids
When a solid body is heated at one end, energy is transferred toward the other end as collisions occur between atoms within the substance.
Convection
the process that takes place in liquids, gases, and solids that are close to their melting point
In these substances, hotter material moves upward toward cooler regions, while cooler material sinks to replace it.
Radiation
the form of heat transfer that occurs from the Sun to Earth. All bodies radiate thermal energy in proportion to their temperature.
aerosols
gas mixtures
surface components
geosphere
hydrosphere
atmosphere
Geosphere
the solid Earth comprising the rocky outer layer—the lithosphere—and its hot interior
Hydrosphere
Earth’s water,whether it is in oceans, lakes or rivers, frozen in ice and snow, or trapped underground in soils and rock fractures
