vocbulary chapter 1-4 Flashcards
What is the Big Bang?
The hypothetical event that started the expansion of the universe from a geometric point; the beginning of time.
What is the Condensation Theory?
Premise that stars and planets accumulate from contracting, accreting clouds of galactic gas, dust, and debris.
What is the Core of the Earth?
The innermost layer of Earth, composed primarily of iron, with nickel and heavy elements. The inner core is thought to be a solid 6,000°C (11,000°F) sphere, while the outer core is a 5,000°C (9,000°F) liquid mass.
What is the Crust of the Earth?
The outermost solid layer of Earth, composed mostly of granite and basalt; the top of the lithosphere.
What is Density Stratification?
The formation of layers in a material, with each deeper layer being denser than the layer above.
What is a Galaxy?
A large, rotating aggregation of stars, dust, gas, and other debris held together by gravity.
What is a Hypothesis?
A speculation about the natural world that may be verified or disproved by observation and experiment.
What is the Mantle of the Earth?
The layer of Earth between the crust and the core, composed of silicates of iron and magnesium.
What is a Nebula?
Diffuse cloud of dust and gas (plural, nebulae).
What is Outgassing?
The volcanic venting of volatile substances.
What is a Planet?
A smaller, usually nonluminous body orbiting a star.
What is a Protostar?
a contracting mass of gas which represents an early stage in the formation of a star, before nucleosynthesis has begun.
What is a Solar System?
The sun together with the planets and other bodies that revolve around it.
What is a Theory in science?
A general explanation of a characteristic of nature consistently supported by observation or experiment.
What is a Compass?
An instrument for showing direction by means of a magnetic needle swinging freely on a pivot and pointing to magnetic north.
What is a Chronometer?
A very consistent clock. It doesn’t need to tell accurate time, but its rate of gain or loss must be constant and known exactly.
What is an Echo Sounder?
A device that reflects sound off the ocean bottom to sense water depth.
What is Latitude?
Regularly spaced imaginary lines on Earth’s surface running parallel to the equator.
What is Longitude?
Regularly spaced imaginary lines on Earth’s surface running north and south and converging at the poles.
Who was Christopher Columbus?
Italian explorer in the service of Spain who discovered islands in the Caribbean in 1492.
Who was James Cook?
Officer in the British Royal Navy who led the first European voyages of scientific discovery.
Who was Charles Darwin?
An English biologist and the co-discoverer of evolution by natural selection.
Who was Eratosthenes?
Ancient Greek mathematician and astronomer known for calculating the Earth’s circumference.
Who was Benjamin Franklin?
Published the first chart of an ocean current in 1769.
Who was John Harrison?
British clockmaker who invented the modern chronometer in 1760.
Who was Ferdinand Magellan?
Portuguese navigator in the service of Spain who led the first expedition to circumnavigate Earth.
Who was Matthew Maury?
The ‘Father’ of physical oceanography, known for systematic study of the ocean.
What is Basalt?
The relatively heavy crustal rock that forms the seabeds, composed mostly of oxygen, silicon, magnesium, and iron.
What are Body Waves?
Seismic waves that travel through Earth’s interior.
What is Continental Crust?
Thicker (up to 65 km), the least dense layer of Earth (2.7-2.8 g/cm³).
What is Continental Drift?
The theory that the continents move slowly across the surface of Earth.
What is a Convection Current?
A single closed-flow circuit of rising warm material and falling cool material.
What is a Convergent Plate Boundary?
A region where plates are pushing together and where a mountain range, island arc, and/or trench will eventually form.
What is a Divergent Plate Boundary?
A region where plates are moving apart and where a new ocean or rift valley will eventually form.
What is Granite?
The relatively light crustal rock that forms the continents, composed mainly of oxygen, silicon, and aluminum.
What is Oceanic Crust?
Thinner (5-10 km), denser (3.0 g/cm³), and much younger than continental crust.
What are P Waves?
Primary waves that travel through the Earth’s interior.
What is Paleomagnetism?
The ‘fossil,’ or remanent, magnetic field of a rock.
What is Pangaea?
The original ‘protocontinent’ named by Alfred Wegener.
What is Panthalassa?
The ocean surrounding Pangaea.
What is Plate Tectonics?
The theory that Earth’s lithosphere is fractured into plates that move relative to each other.
What is Radioactive Decay?
The disintegration of unstable forms of elements, which releases subatomic particles and heat.
What is Radiometric Dating?
The process of determining the age of rocks by observing the ratio of unstable radioactive elements to stable decay products.
What are S Waves?
Transverse waves that vibrate up & down (perpendicularly) to the direction of travel.
What is Seafloor Spreading?
The theory that new ocean crust forms at spreading centers and pushes the continents aside.
What is a Seismic Wave?
A low-frequency wave generated by the forces that cause earthquakes.
What is a Shadow Zone?
The wide band at Earth’s surface 105° to 143° away from an earthquake in which seismic waves are nearly absent.
What is a Transform Fault?
A plane along which rock masses slide horizontally past one another.
What is an Abyssal Hill?
Small, sediment-covered, inactive volcano or intrusion of molten rock less than 200 meters high.
What is an Abyssal Plain?
Flat, cold, sediment-covered ocean floor between the continental rise and the oceanic ridge.
What is an Active Margin?
The continental margin near an area of lithospheric plate convergence.
What is a Continental Margin?
The submerged outer edge of a continent, made of granitic crust.
What is a Continental Rise?
The wedge of sediment forming the gentle transition from the outer edge of the continental slope to the abyssal plain.
What is a Continental Shelf?
The gradually sloping submerged extension of a continent, composed of granitic rock.
What is a Continental Slope?
The sloping transition between the granite of the continent and the basalt of the seabed.
What is a Guyot?
A flat-topped, submerged, inactive volcano.
What is an Island Arc?
Curving chain of volcanic islands and sea-mounts found paralleling the concave edge of a trench.
What is an Ocean Basin?
Deep-ocean floor made of basaltic crust.
What is a Mid-Oceanic Ridge?
An underwater mountain range formed by plate tectonics.
What is a Seamount?
A circular or elliptical projection from the seafloor, more than 1 kilometer in height.
What is a Shelf Break?
The abrupt increase in slope at the junction between continental shelf and continental slope.
What is a Passive Margin?
The continental margin near an area of lithospheric plate divergence.
What is a Submarine Canyon?
A deep, V-shaped valley running roughly perpendicular to the shoreline.
What is a Subduction Zone?
An area at which a lithospheric plate is descending into the asthenosphere.
What is a Trench?
An arc-shaped depression in the deep-ocean floor with very steep sides and a flat sediment-filled bottom.
What is a Turbidity Current?
An underwater ‘avalanche’ of abrasive sediments thought to be responsible for the deep sculpturing of submarine canyons.
