+3/4
Leap Year
24 hour Daylight in Arctic Circle
Month of June
2 factors of Earth
Earth has an oblate spheroid shape
unequal heat distribution due to axial tild (23.5 degrees)
Tropical Year
365.24 days - one complete orbit around the sun
Month of December
axis is tilted away from the sun
Fall Equinox
equal length of day and night
happens during month of September
axis tilted towards the sun
Month of June
days are longer than nights
Month of June
Nights are longer that days
Month of december
Spring Equinox
happens on March
Crust
Earth's thinnest and outermost layer.
Continental crust
upper layer that is granitic
oceanic crust
lower and denser layer that is basaltic
Mohorovicic discontinuity
region between crust and mantle
accretion
accumulation of materials
Mantle
beneath the crust that has 2 layers
2900 km thick (83% of Earth's volume)
asthenosphere
Causes Earthquakes due to its weak layer
Outer core
A layer of molten iron and nickel that creates magnitism and is made up of molten liquid.
Inner core
Made up of solid, iron and nickel
Inner core
Responsible for the Earth's magnetic field
Alfred Wegener
developed the continental drift theory
Pangaea
Means "all land" and refers to the idea that the continents were once one large land mass that began to break millions of years ago
Fit of Continental Shore Lines
fit together like jigsaw puzzles
distribution of glacial sediments
scratches in the surfaces of the continents that acts as proof of existence of glaciers
Paleoclimate
rocks underwent climatic regime
Distribution of Fossils
similar fossils found in several continents
Distribution of rocks
similar type, age and sequence of layers of rocks such as igneous sedimentary and metamorphis
3 types of Plate tectonics
divergent, convergent, transform boundaries.
divergent boundary
A plate boundary where two plates move away from each other in other words, divide.
(ex. n. american and eurosian plate)
Convection Current
hot air rises while cold air sinks
thermophiles
extreme heat
Oceanic Ridge
Underwater Mountain Ridges
Convection Currents
Magma Rising
Mid-Oceanic Ridges
Rift Valleys
Grabens
Space between highlands
Space between mountains
East African Valley
Continental Rifts
small segments in a single landmass
iceland - n. American and Eurasian
convergent boundary
two plates collide.
Subduction Zone
oceanic plates descend in the mantle because it is denser
3 types of Convergent Boundary
Oceanic-Oceanic
Continental-Continental
Oceanic-Continental
Transform Boundary
two plates slide past each other.
ex. san andreas fault
Earthquakes
Natural shaking of ground that causes rapid release of stress in rocks, foreshocks and aftershocks.
Fault
fracture of one body of rocks that slide past each other
Focus
Point where earthquakes originate underground.
epicenter
location or point of the earth's surface directly.
P waves
travels through solids and liquids
S waves
known as shear waves that travels through solids only
Two Types of Surface waves
Love waves
Rayleigh waves
Rayleigh waves
causes damage and destruction and travels only through the crust
Love waves
Travels through the lithosphere that causes ripples
seismograph
detect ground motion
liquefaction
reduction of stiffness and strength of soil
Tsunamis
huge waves generated by an earthquake in coastal areas
magnitude
energy released by an earthquake
ground placement
causes fault scarps in the ground surface
triangulation method
locating the epicenter by using ground motion (atleast three)
intensity
amount of damage caused by the earthquake
precession
planet Earth spins (wobbles) on its own axis.
At noon the sun is directly overhead
June