Chapter 2 Flashcards
Which source of energy fuels earthquakes and volcanoes?
- Earth’s internal energy
Our Solar System was born about 4.6 billion years ago from an interstellar cloud. Put the stages in which the solar system formed in order below, with the first stage at the top and the final at the bottom
- 1) a rotating spherical cloud is made up of gas, ice, dust, and other solid debris
- 2) matter is drawn inward, the speed of rotation increases, and the mass flattens in a disk
- 3) matter accumulates in the center, building the sun
- 4) particles collide, forming larger bodies that become the planets
It is widely believed that the solar system formed through _____.
- collisions of matter within a rotation cloud of gas and dust
Hydrogen and helium are both _____ elements.
- lightweight
Convergent
- plates move towards each other
Divergent
- plates move away from each other
Transform
- plates slide horizontally past each other
The _____, which is composed of the crush and the uppermost mantle, is the rigid, outermost portion of the Earth.
- lithosphere
The ____ is a thick layer of dense rock that comprises 83% of the Earth’s volume and 67% of its mass.
- mantle
The four inner planets are ______.
- Mars, Mercury, Earth, Venus
A failed rift can occur when _____.
- a rift fails to open enough to form a spreading center
In a subduction zone, the less-dense, most buoyant tectonic plate is called the _______.
- overriding
The following are types of tectonic environments
- transform plate boundaries
- divergent zones
- convergent zones
Which of these Earth’s layers has the lowest density?
- crust
What is the name of the outer, low-density layer of Earth, rich in silicon and oxygen?
- crust
The Earth’s core, which is composed mostly of iron, is divided into the _____ inner core and the _____ outer core.
- solid, liquid
The lithosphere, asthenosphere, mesosphere, outercore, and innercore are layers of the Earth that are distinguished from one another by their _____.
- strengths
___ ____ is the study of movements and interactions of the plates.
- plate techtonics
Taken from the Greek word meaning ‘to build’, the term ____ describes the building of topography and the deformation and movement within Earth’s outer layers.
- techtonics
Which bathymetric feature is formed at spreading centres?
- mid-ocean ridge
Which of these features of the Earth are likely the result of widespread melting during the formation of the Earth’s core?
- the crust, which is made of low-density rocks
- a dense atmosphere
- large oceans
What is the magnitude of the largest earthquake ever recorded?
- 9.5
Which of the following are sources of heat generated during the formation of Earth?
- gravitational energy
- impact energy
- radioactive decay
The hot material rising to the Earth’s surface at hot spots originates from deep in the ___.
- mesosphere
The Earth in its infancy probably grew from _____ that formed a more or less homogeneous mixture of materials.
- random collisions of debris
The movement of molten iron inward to form the Earth’s core resulted in ____.
- the release of gravitational energy, which converted to heat.
The concept of _____ explains how mountain ranges float on the denser mantle.
- isostacy
The four outer planets of the solar system are mostly composed of
- hydrogen, helium, and other frozen materials
In which direction is the Pacific plate currently moving?
- North-west
When does subduction occur?
- when a dense lithosphere plate descends beneath a less dense lithosphere plate.
______ is when heat is transferred as electromagnetic waves.
- radiation
The creation of new oceanic lithosphere at an oceanic ridge and its movement away from the ridge is known as ____.
- seafloor spreading
What is subduction?
- the sinking of a dense lithospheric plate under a less–dense lithospheric plate.
What is the magnetic polarity of lava which cooled 1.5 Ma ago?
- reverse polarity
The core, mantle, and crust are layers of the Earth that are distinguished from one another by their different ____.
- densities
The sun’s energy comes from ____.
- the fusion of hydrogen to form helium
Where is the San Andreas fault located?
- At the boundary between the Pacific and North American plates.
The outer layers of the Earth were active in the process of plate techtonics by ____ billion years ago.
- 2.5
Why does the age of ocean basins not exceed approximately 200 Ma?
- the oceanic crust is constantly being recycled by plate techtonics
Across which parts of the world did Wegener match fossils in order to support his theory of continental drift?
- South America, Africa, Antartica, India, Australia
Earth appears to have begun as an aggregating mass of particles and gases about ____ years ago.
- 4.6 billion
What is the orientation of magnetization patterns on the seafloors?
- magnetic stripes are parallel to mid-ocean ridges
The Hudson Bay area is currently experiencing isostatic adjustment following _____.
- the removal of the ice sheets at the end of the last ice age.
What will happen if rifting continues along the East African rift system?
- the African and Somali plates will be separated by a new ocean.
Why are the Himalayas rising a few millimeters per year?
- India is colliding against the Eurasian plate and both plates have the same density which prevents subduction from happening.
The _____ formed through collisions of particles that accreted together, forming larger objects.
- planets