Q2 exam review

S-waves are transverse waves generated by earthquakes. These do not travel through liquids. Because of this, scientists have inferred that the ___________ of the Earth is liquid.

• Crust

• mantle

• outer core

• inner core

Seafloor spreading is a phenomenon that occurs at mid-oceanic ridges, such as the Mid-Atlantic Ridge. New crust, which is created by volcanic activity, spreads away from the ridge. Seafloor spreading could be one reason

• the continents are drifting apart.

• all earthquakes have their epicenters in oceans.

• most active volcanoes are found in the Atlantic Ocean.

• the Mid-Atlantic Ridge is the longest mountain range in the world.

The universe has existed for approximately

• 13.7 light-years.

• 13.7 billion years.

• 13.7 million years.

• 13.7 thousand years.

The map shown here suggests that the MOST LIKELY location of current mountain formation is

• A

• B

• C

• D

Volcanoes are often formed at plate boundaries. This is a convergent plate boundary. From the choices listed, pick the correct description of what happens before the volcano forms.

• Denser continental plate pushes oceanic plate down. Oceanic plate melts deep in the Earth, Magma rises up through weak spot.

• The less dense oceanic plate subducts under the denser continental plate. Subducted plate melts due to heat and pressure. Melted plate, now magma, rises up to the surface.

• As the more dense oceanic plate subducts under the less dense continental plate, it pulls the front edge of the less dense plate down, creating a deep zone or oceanic trench.

• The more dense oceanic plate subducts under the less dense continental plate. Subducted plate melts due to heat and friction. Melted plate, now magma, rises up to the surface.

Scientists who believe in solar nebular theory believe that the formation of the solar system began around

• 4.6 million years ago.

• 4.6 billion years ago

• 37 million years ago.

• 37 billion years ago.

According to the solar nebular theory, a supernova triggered the collapse of a nebula, which began the formation of clumps of gas and dust. According to the solar nebular theory, these clumps MOST LIKELY became the

• Milky Way and the comets.

• Sun and the planets.

• asteroid belt.

• galaxies.

How is the formation of Earth's magnetosphere related to the structure of Earth itself?

• The magnetosphere is that area of space, around a planet, that is controlled by the planet's magnetic field. The attractive force generated by Earth's magnetic and gravitational fields, holds charged particles in this distinct pattern.

• Ions and electrons, both charged particles, emitted from the Sun's surface are pulled toward Earth due to Earth's gravitational force. Because moving charged particles create both an electrical and magnetic field, the magnetosphere is forced around Earth.

• Some particles from the solar wind can enter the Earth's atmosphere. The particles that enter from the magnetotail travel toward the Earth and create an electrical field. Because the Earth is spinning, that electrical field creates a magnetic field as well, the magnetosphere.

• Earth's core is made of magnetic elements, iron, nickel, cobalt. Earth acts as an extremely large magnet, which attracts charged particles that exist in the ionosphere and space. Because the Earth rotates, its hot, magnetic core generates strong electric currents that produce a magnetic field, the magnetosphere.

Earth’s mantle is made of a dense thick material that allows movement of crustal plates. Crustal plate movement occurs because the mantle flows as a result of uneven heating inside the mantle. ____________________ are created by very hot material deep in the mantle rising, then cooling, sinking again, and then heating again and then repeating the cycle.

• magma flows

• magma currents

• convection waves

• convection currents

Which layer is broken up into several plates which "move and float very slowly? Their very slow motion is the cause of plate tectonics, a process associated with continental drift, earthquakes, volcanoes, and the formation of mountains.

• inner core

• outer core

• asthenosphere

• lithosphere