A plate boundary where two plates move away from each other (or divide) creating rift valleys and where crust is created

the scientific study of Earthquakes

the outermost and thinnest layer of the Earth that is divided into plates

Which letter represents the mantle

an instrument located at or near the surface of the Earth that records seismic waves

the process by which new oceanic lithosphere forms as magma rises toward the surface and solidifies

a volcano that has gently sloping sides and can be enormous; are formed from non-explosive eruptions with gently lava flows

Which letter represents the outer core

a major belt of volcanoes that rims the Pacific Ocean

this occurs when two plates collide and one plate moves under the other and sinks into the mantle

a small volcano that forms quickly; they have a dome on top and form from moderately explosive eruptions of pyroclastic material

Which letter represents the crust

Which letter represents the inner core

as the earth rotates the outer core circulates around the inner core and forms this

thinner, more dense, younger crust making ocean floor

seismic waves that cause the most damage

the hypothesis that states that the continents once formed a single landmass, broke up, and drifted to their present locations

the most common type of volcano that has very explosive eruptions of pyroclastic material followed by calm lava flows

a sudden movement of the Earth's crust caused by the release of stress accumulated along geological faults or by volcanic activity; energy is released into the Earth as waves

an underwater mountain chain where new ocean floor is created

a layer of liquid iron and nickel that surrounds the inner core of Earth

a scientist who studies earthquakes

a liquids resistance to flow

a volcanically active area of Earth's surface far from a tectonic plate boundary

a volcano that is erupting or has shown signs that it may erupt in the near future

the earth is composed primarily of

the point on the Earth's surface directly above an earthquake's starting point, or focus

earthquakes occur here because portions of the plates get stuck and then suddenly loosen and move

seismic waves that compress and expand the ground like an accordion; first waves of an earthquake to be detected (fastest)

a thin layer of gases surrounding the Earth

a volcano that has not erupted in recorded history and probably will not erupt again

waves produced by earthquakes

hot molten rock that flows from a volcano (outside the earth's crust)

a volcano that is not erupting but the record of past eruptions suggests that they may erupt again

the thickest layer of the earth between the crust and the core; is the convective layer

the boundary between two tectonic plates that are sliding past each other and cause earthquakes

sections of the Earth's crust that move due to convection currents

the point inside the earth, along a fault, where the earthquake begins

hot molten rock beneath earth's surface

the name of the single landmass that broke apart 200 million years ago and gave rise to today's continents

a tectonic plate boundary where two plates collide creating mountains and volcanoes, crust is destroyed

the layer of the earth that consists of the crust and the rigid upper part of the mantle

the percent of water that covers the earth's surface

a dense sphere of solid iron and nickel at the center of Earth

what causes tectonic plates to move

is thicker and less dense than oceanic crust; is 20-50 km thick

A German scientist who proposed the theory of continental drift

type of seismic body waves that moves the ground up and down or side to side ; they travel the second fastest