Earth’s outermost layer, or lithosphere—made up of the crust and upper mantle—is broken into large rocky plates. These _____ lie on top of a partially molten layer of rock called the asthenosphere. Due to the convection of the asthenosphere and lithosphere, the plates move relative to each other at different rates, from two to 15 centimeters (one to six inches) per year.
plate tectonics
_________ are giant waves caused by earthquakes or volcanic eruptions under the sea
Tsunamis
_________occur along divergent plate boundaries, where a new ocean floor is created as the Earth's tectonic plates spread apart. As the plates separate, molten rock rises to the seafloor, producing enormous volcanic eruptions of basalt.
Mid-ocean ridges
A_______is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface.
Volcano
Extinct volcanoes are not expected to erupt in the future.
Extinct
What are the three tectonic plates boundaries?
divergent, convergent, and transform plate boundaries.
At the beginning of the age of dinosaurs (during the Triassic Period, about 230 million years ago, the continents were arranged together as an angular supercontinent called______.
Pangea
___________ is a geologic process in which tectonic plates—large slabs of Earth's lithosphere—split apart from each other. ________and other tectonic activity processes are the result of mantle convection. Mantle convection is the slow, churning motion of Earth's mantle.
Seafloor spreading
______ is a mixture of molten and semi-molten rock found beneath the surface of the Earth.
Magma
A ___________ volcano is a type of small, steep-sided volcano formed by the accumulation of volcanic debris, primarily cinders (tiny pieces of solidified lava), ash, and rock fragments.
cinder cone
where new crust is generated as the plates pull away from each other.
Divergent Boundaries
An ________ is the shaking of the surface of the Earth resulting from a sudden release of energy in the Earth's lithosphere that creates seismic waves.
Earthquake
_________occurs when an oceanic plate runs into a continental plate and slides beneath it.
Subduction
_________is molten or partially molten rock that has been expelled from the interior of a terrestrial planet or a moon onto its surface.
Lava
A _________, also known as a stratovolcano, is a large, steep-sided volcano built up over time by alternating layers of lava, ash, and other volcanic debris. These volcanoes are characterized by their conical shape, steep slopes, and explosive eruptions.
composite volcano
where the crust is destroyed as one plate dives under another.
Convergent boundaries
In geology, a ___________ is a planar fracture or discontinuity in a volume of rock across which there has been significant displacement as a result of rock-mass movements.
Fault
____________ are long, narrow depressions on the seafloor. These chasms are the deepest parts of the ocean—and some of the deepest natural spots on Earth.
Ocean trenches
Kai lives on the island of Hawaii, and sometimes thin, runny lava actually flows from the volcanoes there. What type of volcanoes are on that island?
Active
A __________volcano is a type of volcano characterized by broad, gently sloping sides, a convex shape, and low-profile features. They are formed by the eruption of highly fluid, basaltic lava, which spreads out over large areas and creates a shield-like structure. Shield volcanoes are among the largest volcanoes on Earth.
Shield
where crust is neither produced nor destroyed as the plates slide horizontally past each other.
Transform Boundaries
____________ describes one of the earliest ways geologists thought continents moved over time. Today, the theory of continental drift has been replaced by the science of plate tectonics.
Continental drift
In geology, a _________ is an area of the Earth's mantle from which hot plumes rise upward, forming volcanoes on the overlying crust.
Hotspot
Dormant volcanoes have not erupted for a very long time but may erupt at a future time.
Dormant
This national park is considered one of the most deadly super volcanoes.
Yellowstone