Earth Science Flashcards
What is “saturation point”?
a stage in which no more substance can be absorbed (hint: clouds).
implication: precipitation happens because it needs to make space for new vapor (hint: grey clouds, rain)
What happens if sunlight hits the earth?
absorption, scattering, reflection (of sun light)
What is a “dew point”?
temperature at which saturation occurs
What happens during “half-life”?
time taken for a radioactive substance to “halve” its quantity
Why is “half-life” considered to be independent?
because it is an intrinsic value
What is erosion?
removal of the top soil (external) –> thick line at diagram)
What is faulting?
zone of fracture at the earth’s crust
What is the most common type of faulting in the Philippines?
strike-slip fault
What is the movement of normal faulting?
land masses “move away” from each other and one slips down (depressed)
What is the movement of reverse faulting?
land masses move “towards each other” , one moves up
What is the movement of strike-slip faulting?
land masses “slide” past each other
What is igneous intrusion?
igneous rock formed deep within the layers of sedimentary rocks/crust
explanation: magma that didn’t become lava and cooled down. It didn’t reach the surface.
What is folding?
Rocks curve/bend during deformation
What is anticline?
high point of folding
What is syncline?
low point of folding
What are uncomformities?
a break in time in an otherwise continuous rock record.
(gap in geological record)
What is cleavage?
plane of weakness at a material
What is hardness?
resistance of material to damage
What is fluorescence?
ability to glow after exposure to UV light
What is radiation?
material that emits radiation
What is the difference between fusion and fission?
Fusion: atoms fuse to make big atomic nuclei
Fission: atoms split
what is diastrophism?
large scale deformation
What is the difference between weathering and erosion?
Erosion: top soil only
Weathering: can be chemical and physical
What are seismic waves?
sudden movements
What are 2 types of seismic waves?
- Surface (love) waves: travel through surface of earth (e.g. ripples of water)
- Body waves: travel through Earth’s inner layers
What are the 2 kinds of body waves?
- P-wave: can move through solid, liquid, gas
- S-wave: can move through solid
List the earth’s layers from least to most dense.
- Continental crust
- Oceanic (Basaltic) crust
- Asthenosphere (upper mantle)
- Lower Mantle
- Outer Core
- Inner Core (Densest): 98% metallic
What layer is known as the “high pressure, high temperature” and “magma zone” of the earth?
Upper mantle
How do scientist know that there is a solid and liquid zone at the Earth’s layers?
seismic waves slow down in liquid zones + volcanic activity
What is the difference between “focus” and “epicenter”?
Focus: exact location
Epicenter: projection at Earth’s surface
What is a subduction zone?
region in which a portion of a tectonic plate sinks beneath another plate into the upper mantle.
Implications:
1. sinking plate disintegrates into molten lava
2. trenches
3. High pressure going up continental plate creates volcanos/mountains
note: oceanic crust sinks because it is denser
What is the Continental Drift Theory (Wegner)?
the continental landmasses were “drifting” across the Earth, sometimes plowing through oceans and into each other.
What did Wegner propose about continents?
continents were once united into a single supercontinent named Pangaea
What evidence was used to prove Wegner’s theory?
Sea Floor Spreading
What is sea floor spreading?
oceanic crust forms along submarine mountain zones, known collectively as the “mid-ocean ridges”, and spreads out laterally away from them.
Explain Carbon-14 dating?
After specimen dies, it stops emitting carbon 14. Scientists use this as a point of reference.
(Decayed/Undecayed = predictable rate)
What is the plate tectonic theory?
- explains how major landforms are created as a result of Earth’s subterranean movements.
- theory that states that Earth’s outer shell is divided into several plates that glide over the mantle.
What are the three kinds of plate tectonic boundaries?
- Convergent: colliding plates
- causes the edges of one or both plates to buckle up into a mountain ranges or one of the plates may bend down into a deep seafloor trench (e.g. Pacific Ring of Fire)
- Divergent: two plates move away from each other
- magma (molten rock) rises from the Earth’s mantle to the surface, solidifying to create new oceanic crust (e.g. Mid-Atlantic Ridge)
- Transform: Two plates sliding past each other (e.g. San Andres fault zone)
- crust is not created or destroyed
What is the movement of the Earth’s rotation on its axis?
clockwise
What is the movement of the Earth’s revolution?
counter-clockwise
What are the characteristics of extrusive igneous rocks?
- small crystals (i.e. “aphanitic” = cannot be seen by the naked eye)
- rapid cooling
What are the characteristics of intrusive igneous rocks?
- course/ large crystals (i.e. “phaneritic = can be seen by naked eye)
- slow cooling - underneath earth’s surface; not exposed to air
What is the most abundant mineral at earth’s crust?
silicates (sand)
What is “specific heat” requirement?
amount of heat requirement for a substance to increase 1°C.
note: S.H. is intrinsic
What are thermal trench?
Mid-Oceanic Ridge: part of oceanic crust moving away each other via convection current (its also Divergent)
Explain the relationship between the Earth and Sun’s gravity?
Newton’s Law of Gravitation:
- Gravitational Force = (Gravitational Constant × Mass of first object × Mass of the second object) / (Distance between the center of two bodies)^2.
Translate: ALL objects attract in proportion to the product of their masses & the square of their distance
Why is Polaris used as a celestial reference point for the Earth’s latitude system?
because it is located over the Earth’s axis
Rocks are classified based on _________.
How they were formed
what are sedimentary rocks?
rocks formed from pre-existing rocks or pieces of once-living organisms
what are metamorphic rocks?
rocks formed by high heat, high pressure
what are igneous rocks?
form when magma (molten rock) cools and crystallizes
What is the earth’s core made of?
iron and nickel
What is low and high pressure air?
low pressure: wet, at warm areas of ocean, rising
high pressure: dry, at cool areas of ocean, sinking
