Geology chapter 1
3. What is a hypothesis?
A hypothesis is a logical but tentative explanation that fits all the data collected and is expected to account for future observations as well.
4. What is a theory? And how does a hypothesis become elevated to a theory?
A theory is a generally accepted explanation for a given set of data or operations. A hypothesis that is repeatedly confirmed by observation and experimentation eventually becomes more widely accepted within the scientific community. Ultimately, a hypothesis that consistently explains all available data may become a theory.
According to current theory, what mechanism drives the movements of the Earth's plates?
Convection is the mechanism driving the movement of the Earth's plates with the help of gravity.
6. What is meant by the "Big Bang" hypothesis?
Cosmologists have proposed that the present universe began as a very small, very hot volume of space containing an enormous amount of energy. Many scientist believe the birth f all the matter in the universe occurred when this space expanded rapidly with a "Big Bang" roughly twelve billion years ago.
15. Name and briefly describe the there types of plate boundaries.
Divergent, convergent, tranform
concept of interrelatedness between different aspects of our physical environment is called_______.
Earths Systems
2. What do geologists do? Summarize this in 40 to 80 words.
Geologists speculate about the origin of the Earth. They examine the wide variety of materials it contains and the processes, such as earthquakes, that act at or near the surface. The subjects of their investigations range from the smallest atoms to entire continents and ocean basins. Some collect and interpret evidence of past life on Earth, to current studies today with lunar rocks. Also search for resources; work to understand geologic hazards and environmental problems... -2
1. Give a definition of the term "geology."
Geology is the scientific study of the Earth's processes and materials.
Why was his hypothesis rejected?
It didn't seem physically plausible.
5. Describe the concept of "uniformitarianism."
It prosed that our observations of current geological processes could be used to interpret the rock record of long-past geological events.
Where do most earthquakes and volcanic eruptions occur?
Near or at plate boundaries
c. Is there an "Atlantic Plate"? What plate (or plates) underlies the North Atlantic Ocean?
No, North American, Eurasian, African
a. In what plate is the state of Florida?
North American
b. What plate lies underneath most of the Pacific Ocean?
Pacific Plate
What is "subduction"? What is "subduction"?
Subduction is when two plates converge and the denser of the two plates goes underneath and sinks into the Earth's interior where it is consumed. Note that this includes two oceanic plates or one continental plate and one oceanic plate.
7. Contrast the composition of the "inner planets" and the "outer planets." Why are they different?
The inner planets consist of Mercury, Venus, Earth, and Mars. The outer planets consist of Jupiter, Saturn, Uranus, and Neptune. The inner planets are rocky and made of iron and nickel. The outer planets are gaseous and made from hydrogen and helium. The inner zone is hot and the outer zone is cold which is why the iron and nickel are in the hot zone and the gases went in the cold zone. Different b/c gases were "blown off" of inner planets by solar radiation.
9. Briefly summarize the origin of the Moon in approximately 30 to 60 words.
The moon came to origin when a planet about the size of Mars collided with the Earth. This caused vaporized crust and mantle to be shot into space. However, the Earth has a very strong gravitation pull that kept these piece from leaving the area and made them form together to create the Moon.
12. Describe the "rock cycle." Give specific examples of how rocks can be converted from one type to another.
The rock cycle is the process by which the various rock types change over time. An igneous rock may weather away and its particles eventually consolidate to become a sedimentary rock. The same igneous rock may remain buried deep beneath the Earth's surface, where heat and pressure may convert it to metamorphic..
What happens when two continental plates collide?
This is called continental collision. The plates are not able to subduct completely. Their edges are dragged down and then brought back up forming a larger single plate. (this creates mountain ranges)
How fast do the plates move?
Very Slow. North American plates are moving westward at about 4 cm per year. Although rates of plate motion may seem insignificant, over the vast course of geological time it can have large consequences.
Tranform
are where plates move past one another in opposite directions.
Igneous Rocks=
cooled and solidified from molten material either at or beneath the Earth's surface.
Metamorphic Rock=
form when heat, pressure, or interior change the mineralogy, chemical composition, and structure of any time of pre existing rock.
Sedimentary Rocks=
forms when pre-existing rocks are weathered and broken down into fragments that accumulate and become compacted or cemented together.
Convection
movement of heat from place to place by a flowing medium.
What happens when a continental and an oceanic plate collide?
oceanic plate subduction
What happens when two oceanic plates collide?
one subducts (this produces earthquakes)
Conduction
passage of thermal energy from atom to neighboring atom.
The idea that the Earth's lithosphere is divided into rigid plates that move is called the theory of
plate tectonics.
Radiation
transfer of heat from a hot object to its cooler surroundings.
Who was Alfred Wegener and what was his hypothesis?
was a German geo-physicist-meteorologist that came up with a theory called continental drift that gave us a basis to understanding plate tectonics. He believe that there was one giant continent called Pangea that was split up to what is the present world today.
Divergent=
where plates move apart.
Convergent
where plates move together.
