GES Exam 1

How many planets are in the solar system?

8

What happens when new oceanic crust is formed at ridges?

As new oceanic crust is formed at ridges, either the Earth's surface area and diameter are expanding or an equal amount of old crust must be getting destroyed somewhere else

Continental Drift

Pangea was slowly disrupted and its fragments slowly drifted to their present positions

Continent-Continent Convergent Margin

both plates are low density and cannot undergo subduction, so they collide to form a continental collision zone; marks final disappearance of an ocean basin, forms spectacular mountain ranges, continental suture zone

How does science advance?

by application of the scientific method

How do scientists explain their observations?

by developing a hypothesis

Magnitude

calculation of the amount of energy released during an earthquake

Deformation

change in shape or size of a body

Magnetic Reversal

changes in direction or orientation of the magnetic field of the Earth that have occurred from time to time

Andesitic Magma

contains about 60% SiO2 and a lot of dissolved gas

Ocean-Continent Convergent Margin

continental crust is much less dense than oceanic crust, continental crust will ride up and over while the oceanic crust gets subducted beneath

What does convection do?

convection brings masses of hot rock upwards from the Earth's interior

What do colliding bodies do?

convert chemical energy into heat energy

Tectonic Cycle

describes the processes whereby Earth's major geological features are formed, including mountain ranges, continents, deep-ocean trenches, and ocean basins

What are the three basic types of plate boundaries?

divergent, convergent, and transform

Supercontinent

each of several large landmasses (notably Pangaea, Gondwana, and Laurasia) thought to have divided to form the present continents in the geological past

Secondary Atmospheres

envelopes of gaseous volatile elements that leaked from their interiors via volcanoes and were trapped by the planets' gravity

Solar Nebula

flattened rotating disc of gas and dust

Continental Shelf

flooded margin of a continent

Fault

fracture that causes slippage of rock

Divergent Plate Margins

fractures in the lithosphere where two plates move apart; also called spreading centers and can occur in plates capped by either continental crust or oceanic crust

Plume

hot material that feeds lava to the surface

Biosphere

includes all of Earth's organisms and matter that has not yet decomposed; the biosphere greatly affects every other of Earth's systems

Hotspot

location where lava is fed to the surface by upwelling masses of hot material

Subduction Zone

location where subduction occurs

Lava

magma that reaches earth's surface

Abyssal Plains

major topographic feature of the seafloor; form as a result of mud settling through the ocean water and burying the seafloor topography beneath a blanket of fine debris

Continental Collision Zone

marks the final disappearance of an ocean basin between converging continents

Oceanic Trench

marks the place where the oceanic-capped lithosphere sinks into the asthenosphere

What do continental collision zones form?

massive mountain chains like the Himalaya

Magma

mixture of molten rock, suspended mineral grains, and dissolved gas that forms in the crust or mantle when temperatures are sufficiently high

What does hot rock do?

near the surface it spreads sideways and cools, becoming denser, and eventually sinking back down in the mantle

What is the scientific method based on?

observations and the systematic collection of evidence that can be seen and tested by anyone with resources

Convergent Plate Margin

occur where two plates are moving toward each other; can occur between plates carrying either oceanic crust, continental crust, or both

What does a hypothesis become?

once it has been examined and found to make successful predictions and withstand numerous tests, a hypothesis may become a theory

What is one consequence of the splitting and spreading of the oceanic crust?

one consequence of the splitting and spreading of the oceanic crust is that older crust is farther from the ridge, and new lava filling the gap along the ridge becomes magnetized with the polarity of the Earth's magnetic field

Ocean-Ocean Convergent Margin

one plate will undergo subduction into the mantle beneath the other plate (called a subduction zone), the plate that will be subjected depends on the velocity and angle of approach

Primary Atmosphere

original envelopes of hydrogen and helium with which they were surrounded early in the history of the solar system

Cryosphere

part of the Earth where the surface is frozen, comprising the area covered by ice sheets and glaciers, permafrost regions, and sea areas covered by ice

Elastic Energy

potential mechanical energy stored in the configuration of a material or physical system as work is performed to distort its volume or shape

Polarity

property of having poles or being polar

What is isostasy?

property whereby the lithosphere maintains flotation balance

Nebular Hypothesis

proposes that the sun and its planets formed from a huge, swirling cloud of cosmic gas and dust

Caldera

roughly circular, steep-walled basin several kilometers or more in diameter

Continental Slope

sharp drop off at the seaward edge of the continental shelf

Geosphere

solid earth composed of mainly rock and regolith; where energy that comes into the Earth system from outside sources meets energy that comes from within the planet, energy sources combine and compete to build up and wear down materials of the Earth's surface

Liquefaction

sudden disturbance of sediment and soil that turns solid ground to a liquid-like mass of quicksand

What are the four systems?

the atmosphere, the geosphere, the hydrosphere, and the biosphere

What does the lithosphere have?

the energy of motion

Atmosphere

the envelope of gases surrounding the earth or another planet-outer boundary of the earth system; very very thin layer, but it protects life from damaging solar radiation, is the reservoir for oxygen and carbon dioxide

Isostasy

the equilibrium that exists between parts of the earth's crust, which behaves as if it consists of blocks floating on the underlying mantle, rising if material (such as an ice cap) is removed and sinking if material is deposited

Seafloor Spreading

the formation of new areas of oceanic crust, which occurs through the upwelling of magma at midocean ridges and its subsequent outward movement on either side

Intensity

the measurable amount of a property, such as force, brightness, or a magnetic field

Hydrologic Cycle

the natural sequence through which water passes into the atmosphere as water vapor, precipitates to earth in liquid or solid form, and ultimately returns to the atmosphere through evaporation

Earth System Science

the new holisitic approach to studying the Earth as a whole system of many interacting parts: the ocean, the atmosphere, the continents, lakes and rivers, soils, plants, and animals

What topographic features can subduction zones include and where do they occur?

the occur in closing oceanic basins and include oceanic trenches, arc-shaped chains of volcanic islands, island or magmatic arcs

Anthroposphere

the part of the environment that is made or modified by humans for use in human activities and human habitats; includes the technosphere, specifically to technology, machines, and the built environment

Epicenter

the point on the earth's surface that lies vertically above the focus

What is tectonics?

the study of the movement and deformation of these plates

Solar System

the sun together with all the planets and other bodies that revolve around it

Hydrosphere

the totality of earth's water including oceans, lakes, streams, underground water, and all snow and ice; the perennially frozen parts of the hydrosphere are collectively the cryosphere; the hydrosphere and the atmosphere store, purify, and continually redistribute water

Body Wave

travel outwards in all directions from the focus and have the capacity to travel through earth's interior

P (Primary) Wave

waves that are first to be recorded by a seismograph after an earthquake

Fissure Eruption

when lava reaches earth's surface through a vent that is an elongate fracture in the crust

Subduction

when slabs of of lithosphere capped by old, cold oceanic crust sink into the asthenosphere along the downing limbs of mantle convection cells

Partial Melt

when temperature increases enough for part of the materials in a rock to melt and part of it to remain solid

Strike-Slip

where two plates are sliding past each one another laterally

What are divergent plate margins?

where two plates move apart, spreading centers, constructive margins, occur in plates capped by either continental or oceanic crust, start on a continent and become an ocean; eventually they split, forming a rift and start the cycle of spreading

Convergent Plate Margins

where two plates move towards each other, destructive margins, occur between plates carrying either oceanic crust, continental crust, or both, behave differently when they converge

Transform Fault Plate Margins

where two plates slide past each other in a horizontal or strike-slip motion; can occur in oceanic or continental crust; conservative margins where crust is neither created nor destroyed, San Andreas fault is an example

Moon

any natural object in a regular orbit around a planet

Terrestrial Planets

any of the four planets, Mercury, Venus, Earth, and Mars, whose orbits are closest to the sun; small, rocky, metallic, and dense

System

any proportion of the universe that can be isolated from the rest of the universe for the purpose of observing and measuring changes

Basaltic Magma

approximately 80% of all magma erupted from volcanoes is basaltic; contains 50% SiO2 and little dissolved gas

How do all major topographic features on Earth's surface arise?

as a direct result of the motion and interaction of lithospheric plates

Planet

a celestial body moving in an elliptical orbit around a star

Eruption Column

a cloud of hot volcanic ash suspended in volcanic gas emitted during an explosive volcanic eruption

Galaxy

a collection that consists of a billion or more stars

Rift

a crack, split, or break in something

Planetary Accretion

a gathering of more and more bits of solid matter from surrounding space

Theory

a generalization about nature

Scientific Method

a logical research strategy that has developed through trail and error over many years; based on observations and the systematic collection of evidence that can be seen and tested by anyone with the resources to do it

Meteorite

a mass of stone or metal that has reached the earth from outer space; a fallen meteoroid.

Continental Rise

a region of gently changing slope where the seafloor flattens ou and continental crust meets oceanic crust

Magnetic Field

a region of space near a magnet, electric current, or moving charged particle in which a magnetic force acts on any other magnet, electric current, or moving charged particle

Cycle

a series of events that are regularly repeated in the same order

Law of Science

a statement that some aspect of nature is always observed to happen in the same way and that no deviations from the rule have ever been seen

Transform Fault Plate

a strike-slip fault that offsets a mid-ocean ridge in opposing directions on either side of an axis of seafloor spreading

Hypothesis

a supposition or proposed explanation made on the basis of limited evidence as a starting point for further investigation

Plate Tectonics

a theory explaining the structure of the earth's crust and many associated phenomena as resulting from the interaction of rigid lithospheric plates that move slowly over the underlying mantle

What may theories become?

a theory or group of theories whose applicability has been decisively demonstrated, may become a law or a principle

Active Volcano

a volcano that has erupted within historic times

What do active continental margins have?

active continental margins, formed by ocean-continent subduction, have a continental volcanic arc

Continental Shield

an assemblage of cratons and orogens

Elastic Rebound

an explanation for how energy is spread during earthquakes. As rocks on opposite sides of a fault are subjected to force and shift, they accumulate energy and slowly deform until their internal strength is exceeded

What do scientists start with?

an observation; they then seek to acquire evidence about it through measurement and experimentation

Sun

an ordinary star that is dominated by hydrogen and helium at 98% of its mass; provides the light and energy for life to exist on Earth

Paleomagnetism

ancient magnetism locked in minerals, preserves a record of Earth's magnetic field at the time of rock formation

What evidence suggest that each mechanism operates to some extent?

• Old, cold lithosphere breaks and begins to sink, pulling downward on the plate • Then downhill slide and ridge push combine to keep the process going • In addition, the exact configuration of convection cells in the mantle is cause for scientific debate

What three forces might play a role in moving the brittle slabs of the lithosphere around?

• Rising magma at oceanic ridges may push plates away from each other • Lithosphere breaks, sinks into the asthenosphere, dragging the plate away • The whole plate may be sliding downhill away from the spreading ridge