Test 1 Flashcards
What are the Sciences that make up Earth Science?
Geology, Oceanography, Meteorology, Astronomy, Environmental Science
What is Geology?
The study of the solid Earth. Physical geology examines the materials that
comprise the Earth and historical geology aims to understand the origins and
development of the planet.
What is Oceanography?
Examines the composition and dynamics of the world’s oceans. It
also involves the study of coastal processes and seafloor topography as well as
marine life.
What is Meteorology?
The study of Earth’s atmosphere. It includes weather and climate.
What is Astronomy?
Examines Earth as a body in space, both as part of the solar system and
as part of a larger universe
What is Environmental Science?
Includes the study of natural resources, environmental
hazards, and how people influence their environments and Earth processes.
List at least four natural hazards. Aside from natural hazards, describe another important
connection between people and Earth Science.
Different natural hazards include: Earthquakes, Volcanoes, Floods, Tsunami, Hurricanes,
and Landslides. Humans influence Earth by altering its surface. People build cities and
roads, and engineer projects that alter river flooding patterns. People pollute the air, the
land, and the water, changing Earth from what is its natural state.
List two examples of size/space scales in Earth Science that are at opposite ends of the
spectrum.
1) A lightning flash happens within a fraction of a second but can instantly alter the
immediate landscape.
2) Uplift of mountain ranges takes tens to hundreds of millions of years to occur.
How old is the Earth?
Earth is 4.6 billion years old.
If you compress geologic time into a single year, how much time has elapsed since Columbus
arrived in the New World?
3 Seconds.
How is a scientific hypothesis different from a scientific theory?
A hypothesis is an untested explanation for an observed phenomenon. It requires further
observation or testing to see if it is valid. A theory is generally accepted by the scientific
community as the best explanation for observable facts, as it has been subjected to rigorous
scrutiny and tested repeatedly.
Summarize the basic steps used in many scientific investigations.
1)An observation is made about the natural world. 2)Data surrounding that observation are collected. 3)A working hypothesis is developed. 4)More observations and/or experiments are performed to test the hypothesis. 5)The hypothesis is accepted, rejected, or modified. 6)Data and results are shared with the scientific community for critical analysis and
further testing.
Name and briefly outline the theory that describes the formation of our solar system.
The theory that describes the formation of our solar system is the nebular theory, which
states that the early solar system originated as a cloud of dust and gas about 5 billion
years ago as a star gravitationally collapsed. This rotating nebular cloud eventually
contracted into a flattened, rotating disk. The cloud cooled and heavier metallic and rocky
material condensed and accreted into the inner planets. The outer planets formed from
residual gases and ices in the outer nebular cloud.
List the inner planets and outer planets. Describe basic differences in size and composition
Inner planets: Mercury, Venus, Earth, and Mars. These planets are relatively small and
rocky; they are made up largely of metals and silicate minerals.
Outer planets: Jupiter, Saturn, Uranus, and Neptune. These planets are much larger than
the inner planets and are composed of ices and gases.
List the four spheres that constitute the Earth system.
Atmosphere, Hydrosphere, Biosphere, and Geosphere
Compare the height of the atmosphere to the thickness of the geosphere.
The atmosphere is a very thin layer compared to the planet itself. The radius of the solid
Earth is about 6400 km (4000 mi) whereas the entire atmosphere is roughly 160 km (100
mi) thick.
How much of Earth’s surface do oceans cover? What percentage of Earth’s water supply
do oceans represent?
Oceans cover nearly 71% of the planet. They account for 97% of Earth’s water supply.
What is a system. List three examples.
A system is a group of interacting, independent parts that make up a complex whole.
Examples of systems include a city transportation system, a weather system, or an
automotive cooling system.
What are the two sources of energy for the Earth system?
The Sun and Earth’s interior are the two sources of energy for the Earth system.
Compare and contrast continents and ocean basins.
Continents are made of granitic rocks whereas oceans are made of basaltic rocks.
Continents are less dense and thicker than ocean basins
Name the three major regions of the ocean floor. What are some physical features
associated with each?
Continental margins – contains the continental shelf, the continental slope, and the
continental rise. They are the boundary between continents and oceans.
Deep-ocean basins – include the vast, flat abyssal plains of the ocean bottom. They
also contain deep ocean trenches and seamounts in varied stages of erosion.
Oceanic ridges – are divergent plate boundaries where new igneous rock is
formed. These are vast winding ridges of underwater volcanic mountains that wind
around the Earth.
Describe the general distribution of Earth’s youngest mountains.
Earth’s youngest mountains are generally found at the margins of continents along as
opposed to the stable interior of continents.
What is the difference between shields and stable platforms?
A shield is a large stable area of very old crystalline rock. A stable platform is a shield
covered by sedimentary rock
Why did the ancients believe that celestial objects had some influence over their lives?
Early cultures noticed a connection between the seasons, tides, floods, and certain
celestial bodies. Because seasons, tides, and floods were important in their agriculture, they
believed that the heavenly bodies also controlled this part of their lives.
What is the modern explanation of the “guest stars” that suddenly appeared in the night sky?
They are normal stars that are usually too faint to be visible but increase in
brightness as they explosively eject gases from their surface. They are known as novae or supernovae
Explain the geocentric view of the universe.
The geocentric view of the universe places Earth at the center of all planetary bodies,
including the Sun and stars. The idea is that all other things revolve around a motionless Earth
Describe what produces the retrograde motion of Mars. What geometric arrangements did
Ptolemy use to explain this motion?
The retrograde motion of Mars is due to Earth having a faster orbital speed than
Mars. From the point of view of a stationary Earth, Mars appears to move backward, or
retrograde. Ptolemy described this motion geometrically by proposing that the planets orbited on
small circles (epicycles) revolving on large circles (deferents
What major change did Copernicus make in the Ptolemaic system? Why was this change
philosophically different?
Copernicus proposed a heliocentric model with the Sun at the center of the solar
system. It was philosophically different because it was considered heretical to not view
Earth as the center of the universe.
What data did Tycho Brahe collect that was useful to Johannes Kepler in his quest to
describe planetary motion?
Tycho Brahe collected precise observations about the locations of Mars.
Who discovered that planetary orbits are ellipses rather than circles?
Johannes Kepler discovered that planetary orbits are ellipses rather than circles
Explain how Galileo’s discovery of the phases of Venus supported the Copernican view of
a Sun-centered universe
Galileo discovered that the planet Venus exhibits phases that would be impossible in
Ptolemy’s geocentric model. In addition, the phases of Venus also changed size,
indicating that Venus was closer to Earth when a “crescent,” and farther away when
close to “full.” This could be most simply explained by saying that Earth and Venus
were both orbiting the Sun, with Venus’ orbit entirely inside the Earth’s orbit.
How are the constellations used in modern astronomy?
Modern astronomers use constellations to roughly identify the area of the night
sky they are observing.
How many constellations are currently recognized
Eighty-eight constellations are currently recognized.
Describe the celestial sphere
The celestial sphere is a conceptual sphere with Earth located at its center and
all objects in the sky projected upon the inner surface of the celestial sphere. The
poles of the celestial sphere are aligned with the poles of the Earth. The celestial
equator lies along the celestial sphere in the same plane that includes the Earth’s
equator.
Describe how you can use your outstretched hand to estimate angular distances.
With your hand held out at arm’s length, the angular distance represented by
your hand with fingers fully spread is about 20 degrees. The width of your index
finger is about 1 degree, and the width of your closed fist represents about 10
degrees.
Describe the three primary motions of Earth.
Rotation—Earth rotates on its axis once every 24 hours.
Revolution—Earth orbits the Sun once per year.
Precession—Earth’s axial tilt slowly changes direction every 26,000 years
Explain the difference between the mean solar day and the sideral day.
The mean solar day is the interval between noon on one day and noon the next day. The
sidereal day is how long it takes Earth to make one rotation, which is 23 hours, 56 minutes, 4
seconds.
Define ecliptic.
The ecliptic is the apparent path of the Sun during the course of one year.
Compare the synodic month with the sideral month
The synodic month is 29.5 days, or how long it takes for the Moon to pass through all its
phases. The sidereal month is how long it takes the Moon to orbit Earth, which is 27.3 days.
The moon rotates on its axis very slowly. How does this affect the lunar surface
temperatures?
Because the Moon rotates on its axis very slowly, there is a high temperature on the day
side of the Moon and a very low temperature on the night side
