Earth Science Flashcards
KMSSS
epicentre
the point on Earth’s surface directly above the focus of an earthquake
erosion
the gradual wearing away and removal of rock at the surface of Earth
igneous rock
a type of rock formed by the cooling and solidification of magma or lava
lava
molten rock above Earth’s surface
lithification
the process in which sediments come together to form sedimentary rock
lithosphere
a layer of earth consisting of the crust and the lithospheric mantle
magma
molten rock located below Earth’s surface
metamorphic rock
a type of rock formed by heat and pressure
mineral
a naturally-occurring, inorganic solid substance
protolith
The original rock that has undergone metamorphism.
rock cycle
an idealised series of processes undergone by rocks in Earth’s crust that change rocks from one type to another
sedimentary rock
a type of rock formed by the accumulation and lithification of sediment
subduction
a geological process at convergent boundaries where one tectonic plate sinks beneath another plate
tsunami
a large ocean wave (or series of waves) caused by the displacement of large amounts of water, typically due to an earthquake or large landslide
weathering
the gradual breakdown of rock while it remains in the same place; weathering can be caused by many things, including heating, cooling, wind, rain, chemical reactions, plant roots and human activity
What is continental drift?
The theory that the continents were once joined to form the supercontinent ‘Pangea’, then broke apart into several continents over millions of years and drifted to their current positions.
What are 3 pieces of evidence to support continental drift?
- Shapes of continents matching up at coastlines
- Similar plants and animal fossils of the same age across continents
- Mountain chains and rock types matching up
What is the relative plate movement at convergent boundaries?
Growing closer
What is the relative plate movement at divergent boundaries?
Growing apart
What is the relative plate movement at transform boundaries?
Sliding along each other
What boundary type is crust formed? What are the geographic features of this?
Divergent boundaries:
Oceanic oceanic - mid-ocean ridge, undersea volcanoes
Continental continental - rift valley, volcanoes
What boundary type is crust destroyed? What are the geographic features of this?
Convergent boundaries:
Oceanic continental - oceanic trench (where crust sinks), volcanic arc (inland, wherre melted rock rises), oceanic crust sinks
Oceanic oceanic - oceanic trench (where crust sinks), volcanic island arc (islands formed by underwater volcanoes), denser crust sinks
Continental continental - mountain ranges, both crusts don’t sink and form high mountains
What are the three types of rocks?
Igneous, sedimentary and metamorphic
How are the three types of sedimentary rocks formed?
Clastic, chemical, biological
Clastic: formed from sediments of pre-existing rock, clasified by the size of sedimental grains (or clasts)
Biological: formed from remains of dead organisms (plant or animal)
Chemical: formed from dissolved minerals when water evaporates
What are the three methods to form sedimentary rocks and how do they occur?
Compaction, cementation, recrystallisation
Compaction: Sediments are pressed together by pressure from overlying sediment
Cementation: Dissolved minerals in the water between sediment particles crystallise and cement the sediment particles together
Recrystallisation: minerals in the sediment exposed to water change their structure and recrystallise
What are the two types of weathering and what causes them?
Mechanical, chemical
Mechanical weathering: no change in chemical composition, caused by temperature change, freezing/thawing of water, root action
Chemical weathering: change in chemical composition, caused by oxygen, rainwater, carbon dioxide
What are the 5 major issues related to volcanic eruptions?
Toxic gases: harmful if inhaled, form acids when dissolved in water + cause acid rain/lake acidification
Lava flow: 700-1200 degrees celsius, usually slow so people can run away but fixed objects/plants cannot
Pyroclastic flow: mixture of solids, liquids and gases at over 1000 degrees, run down volcano like avalanch (>100km/h), deadliest aspect of volcano
Lahar: mudflow full of debris that can run down a volcano, acts like flash flood
Volcanic ash release: tiny fragments of minerals + rocks suspended in air like dust, fill alveoli in lungs and make it difficult to breathe, over plant leaves and prevent photosynthesis, darken sky and prevent sunlight from reaching ground, disrupt weather patterns
What characteristics of P and S waves have provided information about the interior of Earth?
S-waves cannot travel through a liquid, but P-waves can. P-waves were detected travelling all the way to the other side of the earth but S-waves were not, so we can determine that the outer core is liquid.
