Scope 3: Plate Tectonics Flashcards
Fossils
preserved parts or traces of animals that lived in the past
crust
the thin, solid, outermost layer of Earth, is either landmasses or ocean floors
mantle
the solid layer of Earth below the crust and above the coreli
lithosphere
the outermost part of Earth, comprising of crust and the uppermost part of the mantle
asthenosphere
middle part of the mantle, both solid and partly melted which allows tectonic plates to move. this floating is known as plasticity.
how slow does the asthenosphere move every year?
2-4 cm annually
core
the two-part layer of earth below the matnel with a liquid outer core and a solid inner core.
what is the outer core made up of?
molten material of mostly iron
what is the inner core made up of?
mostly of iron
tectonic plates
huge pieces of crust that slowly move on the upper part of the mantle
continental drift
the theory that continents were once connected but have drifted apart.
convection
heat transfer caused by the rising of hotter, less dense fluids and the falling of cooler, denser fluids.
convection currents
a circular movement caused by the rising of hotter, less dense fluid.
plate tectonics
the theory that the lithosphere is divided into tectonic plates that slow moe on top of the asthenosphere.
magma
melted or molten rock material beaneath earth’s surface.
what are trilobites?
anthropods that existed for almost 300 million years.
where did trilobites first appear?
about 521 million years ago (died out about 251 million years ago before dinosaurs)
where are trilobites found?
almost everywhere on earth
what are transform boundaries?
a place hwere two tectonic plates slide past each other
what do transform boundaries cause?
earthquakes
what are divergent boundaries?
the boundary between two tectonic plates moving away from each other, creating rift valleys on land, new ocean crusts on seafloors
what do divergent boundaries cause?
mid-ocean ridges, sea floor spreading, and new ocean floors
what are convergent boundaries?
a place where two tectonic plates move toward each other and collide
what do convergent boundaries cause?
volcanoes and mountains
what is a subduction?
- when one plate is forced down into the mantel (volcanoes
- occurs to continent, ocean plate always subducts to continental plate, earthquakes to creat tsunamis
- continent to continent, creates mountains
what is the first layer of the earth?
the crust - ocean floors and continental landmasses
what is the second layer of the earth?
the lithosphere
what is the third layer of earth?
the mantle
what is the fourth layer of the earth?
the asthenosphere, or the middle part
what is the fourth layer of earth?
the outer core
what is the fifth layer of earth
the inner core
what are the two types of crust?
the two types of crust are the oceanic and continental crusts
what two processes does convection produce?
two processes produced by convection currents are earth’s magnetic fields and tectonic plates
