Planet Earth Flashcards
rocks, earthquakes, volcanoes, and mountains
What is an Igneous rock?
an igneous rock is a rock that forms when hot magma or lava cools.
What is an igneous intrusive rock?
an igneous intrusive rock is a rock that forms when magma hardens below earths surface resulting in large crystals due to the length of time it cools.
What is a Igneous extrusive rock?
an igneous extrusive rock is a rock that forms when lava has harden above earth surface. since it is not as hot as underground earth, it cools quicker resulting in smaller crystals.
what is a sedimentary rock?
A sedimentary rock is a rock that has many layers from cementation and compaction. (made up of sediments)
What is a metamorphic rock?
a metamorphic rock is a rock that is formed when heat and pressure is added.
what is erosion?
erosion is the movement of particles that have been broken apart from weathering.
what is weathering?
weathering is the process in which rock pieces are broken up due to the three types of weathering.
what are the three types of weathering?
physical weathering ( actual rain) Chemical weathering (Acid rain) Biological weathering (tree roots or animals breaking rocks)
what is the continental drift? (moving crust)
Alfred Wegener proposed that the continents were all connected at one time with many pieces of evidence.
- land based fossils were fount in south america and africa ( they couldnt have gone from place to place unless the continents were together
- plant fossils can be found in different continents and seperated by ocean
- the shapes of the continents fit together
- geological evidence. some rock are the same but found in opposite areas.
what are converging plates?
plates that come together ( Juan de Fuca and North American Plate.
what are diverging plates?
plates that are moving away from each other. ( like plates along Mid- Atlantic ridge)
what are convection currents?
hypothesized that earth moves slowly due to convection currents. they have convergent boundries: when two plates collide and the more dense material will sink below. That is called a subduction zone.
What is an epicentre?
an epicentre is the point on the surface of earth where the location of the earthquake is.
what is a focus?
the origin of the earthquake (usually below earths surface)
what is a normal earthquake?
tension stretches and pulls plates apart
