Chapter 1 - ESC1000 Flashcards
What is Earth Science?
The name of all the sciences that collectively seek to understand Earth.
What sciences are included in Earth Science?
Geology, Oceanography, Meteorology, and Astronomy.
What is geology?
The science that examines Earth, its form and composition, and the changes is has undergone and is undergoing.
What are the 2 typical areas of geology?
Physical geology and historical geology.
What is physical geology?
Area of geology that examines the materials composing Earth and seeks to understand the processes that operate beneath and upon its surface.
What is historical geology?
Area of geology that aims to understand the origin of Earth and the development of the planet through its 4.6 billion year history.
What is oceanography?
The scientific study of the oceans and oceanic phenomena.
What is meteorology?
The scientific study of the atmosphere and atmospheric phenomena; the study of weather and climate.
What is astronomy?
The scientific study of the universe, which includes the observation and interpretation of celestial bodies and phenomena.
What are the 3 main problems addressed by Earth Science?
Natural hazards, resources, and human’s influence on earth processes.
What is geologic time?
The span of time since the formation of Earth, about 4.6 billion years.
What is a hypothesis?
A tentative explanation that is tested to determine whether is valid.
What is a theory?
A well-tested and widely accepted view that explains certain observable facts.
What is the scientific method?
The process by which researchers raise questions, gather data, and formulate and test scientific hypotheses.
What are the steps of the scientific method?
- Raise a question.
- Background research: collect scientific data.
- Construct a hypothesis.
- Develop observations and/or experiments that test the hypothesis.
- Analyze the data.
- Share with scientific community for critical evaluation and additional testing if results support the hypotheses. Try again if results partially support or do not support the hypothesis.
When did the universe begin approximately?
13.7 billion years ago.
What theory explains the formation of the solar system?
The nebular theory.
What is the nebular theory?
The basic idea that the sun and planets formed from the same cloud of dust and gas in interstellar space.
Explain the nebular theory.
- The birth of the solar system began as a cloud (nebula) of dust and gases and started to collapse under its own gravity.
- The nebula contracted into a flattened, rotating disk that was heated by the conversion of gravitational energy into thermal energy.
- The disk’s center formed the Sun. As the rest of the disk cooled down, tiny particles of metal, rock, and ice condensed within it.
- Over tens of millions of years, these particles clumped into larger masses, which collided to form asteroid sized bodies, which later formed planets.
What are the four inner planets?
Mercury, Venus, Earth, and Mars.
What are the four outer planets?
Jupiter, Saturn, Uranus, and Neptune.
What is the difference between the inner and the outer planets?
The composition. The inner planets are mostly composed of metal and rock and the outer planets are made up of lighter components such as water, carbon dioxide, ammonia and methane.
What is the Earth System?
Earth viewed as a dynamic system of interacting parts and processes.
What are the 4 spheres of Earth?
Hydrosphere, Atmosphere, Biosphere, and Geosphere.
What is the hydrosphere?
The water portion of Earth; one of the subdivisions of Earth’s physical environment.
What is the distribution of water in the hydrosphere?
Oceans represent 96.5%, freshwater represents 2.5%, and saline groundwater and lakes represents 0.9%.
What is the atmosphere?
The gaseous portion of the planet; one of the subdivisions of Earth’s physical environment.
What is the biosphere?
The totality of life on Earth; one of the subdivisions of Earth’s physical environment.
What is the geosphere?
The solid Earth; the largest of the subdivisions of Earth’s physical environment.
What are the layers of Earth based on chemical composition?
Core (iron + nickel) , Mantle (high density rock), and Crust (low density rock).
What are the layers of Earth based on physical properties?
Inner core (solid), Outer Core (liquid), Lower Mantle (solid), Upper Mantle (solid) and Crust (solid and rigid).
What is the asthenosphere?
A division of the mantle situated below the lithosphere. This zone of weak materials exists below a depth of 100 km and it can extend to almost 700 km. The rock within this zone is easily deformed.
What is the lithosphere?
The rigid outer layer of Earth, including the crust and the upper mantle.
What are the 2 divisions of crust based on physical properties?
Continental crust and Oceanic crust.
What are the 2 sources of energy for the Earth system?
The sun that drives external processes in the atmosphere, hydrosphere and Earth’s surface and the Earth’s interior that drives the internal processes that occur in the geosphere.
What are the 2 principal divisions of Earth’s surface?
Ocean basins and continents.
What is an ocean basin?
A deep submarine region that lies beyond the continental margins.
What is the average density of the oceanic crust and thickness?
About 3.0 g/cm3 and 7 km.
What is a continent?
Large, continuous areas of land that include the adjacent continental shelf and islands that are structurally connected to the mainland.
What is the average density of the continental crust and thickness?
About 2.7 g/cm3 and 35 km.
What is the result of these differences in physical properties of the continental crust and oceanic crust?
The thicker and less dense continental crust is more buoyant than the oceanic crust. As a result, continental crust floats on top of the deformable rocks of the mantle at a higher level.
What are the 3 major regions of the ocean floor?
Continental margins, deep-ocean basins, and oceanic ridges.
What is a continental margin?
The portion of the seafloor adjacent to the continents.
What are the 3 components of the continental margin?
Continental shelf, continental slope, and continental rise.
What is the continental shelf?
The gently sloping submerged portion of the continental margin, extending from the shoreline to the continental slope.
What is the continental slope?
The steep gradient that leads to the deep-ocean floor and marks the seaward edge of the continental shelf.
What is the continental rise?
The gently sloping surface at the base of the continental slope.
What are the deep-ocean basins?
The portion of the seafloor that lies between the continental margin and the oceanic ridge system.
What are 3 features of the deep-ocean basins?
The abyssal plains, deep-ocean trenches, and seamounts.
What are the abyssal plains?
A very level area of the deep-ocean floor, usually lying at the foot of the continental rise.
What are deep-ocean trenches?
An elongated depression in the seafloor produced by the bending of the oceanic crust during subduction.
What are seamounts?
An isolated volcanic peak that rises at least 1000 meters above the deep-ocean floor.
What are oceanic ridges?
A broad, linear ridge or rise on the ocean floor. The rift at the crest of the ridge represents a divergent plate boundary where new oceanic crust is generated.
What are the 2 major features of the continents?
The uplifted regions of deformed rocks that make up mountain belts and the extensive flat, stable areas that have eroded nearly to sea level.
How are the mountains divided?
They are divided by age. The young mountain belts are less than 100 million years old while the old mountain belts are older than 100 million years.
What are mountain belts?
A geographic area of roughly parallel and geologically connected mountain ranges developed as a result of plate tectonics.
How is the stable interior of the continent called?
Craton.
What is the craton?
The part of the continental crust that has attained stability; that is, it has not been affected by significant tectonic activity during the Phanerozoic eon. It consists of the shield and the stable platform.
What is the shield?
A large, relative flat expanse of ancient metamorphic rock within the stable continental interior.
What is the stable platform?
The part of the craton that is mantled by relatively undeformed sedimentary rocks and underlain by a basement complex of igneous and metamorphic rock.
