What is Wegener’s theory on continental drift?
the continents were once united into a single supercontinent called Pangaea
What is a magnetic reversal?
the process by which the North pole is transformed into a South pole
Explain the difference between divergent and convergent boundaries.
Convergent boundaries have plates that move towards each other, whereas divergent boundaries have plates that move away
Explain hotspot volcanoes and hotspots and plate motion.
The heat that fuels the hot spot comes from very deep in the planet. This heat causes the mantle in that region to melt. The molten magma rises up and breaks through the crust to form a volcano. While the hot spot stays in one place, rooted to its deep source of heat, the tectonic plate is slowly moving above it.
What makes magma?
Differences in temperature, pressure, and structural formations in the mantle and crust
What was the supercontinent that was a single landmass of all the continents?
Pangea
What is paleomagnetism?
the branch of geophysics concerned with the magnetism in rocks that was induced by the earth's magnetic field at the time of their formation.
What are the three types of convergent boundaries? Explain each type.
oceanic-continental convergence, oceanic-oceanic convergence, and continental-continental convergence.
What is it called when lava flows out of long cracks in Earth’s crust? What are the cracks called?
Fissure/vent
What is the composition of magma?
oxygen, silicon, aluminum, sodium, and potassium
What are the three forms of evidence for Pangea? Explain all three
1) the shapes of the continents, 2) the distribution of geological formations and 3) the movement of the continents
What is an isochron?
a line on a diagram or map connecting points relating to the same time or equal times.
What is a transform boundary?
they connect other plate boundaries in various combinations
What is the tubelike structure that lava uses to reach the surface?
lava tubes
What is a pluton?
a deep-seated intrusion of igneous rock
What is a magnetometer?
a device that measures magnetic field or magnetic dipole moment.
Explain seafloor spreading
a geologic process in which tectonic plates—large slabs of Earth's lithosphere—split apart from each other.
What is volcanism?
Volcanism is the eruption of molten rock from inside the Earth to the surface.
What is the opening that the lava emerges through?
vent
What are the erupted materials from a volcanic eruption?
gas, lava, and fragmented debris called tephra.
What is the Mariana Trench and what mountain range could fit inside?
Everest, the highest mountain in the world at 8,849 m, would easily fit inside it.
What are tectonic plates?
a massive, irregularly shaped slab of solid rock
What are hot spots?
an area on Earth over a mantle plume or an area under the rocky outer layer of Earth
What are the three types of volcanoes? Describe each one.
Composite cones, shield volcanoes, cinder cones and supervolcanoes
Explain what pyroclastic flows are.
extremely destructive and deadly because of their high temperature and mobility.