Calvin W.'s Review for MSP
#RockinReview

1. Waxing means any time after the new moon and before the full moon.  It is called this because the illuminated area is increasing.

2. Waning means any time after the full moon and before the new moon.  It is called this because the illuminated area in decreasing.

3. Gibbous means convex at both edges.  This happens when the moon is more than half full.

4. Crescent means a segment of a ring tapering to points at the ends.  This happens when the moon is less than half full.

5. You have a waxing moon in between the new and first quarter moon as well as in between the first quarter and full moon.  You have a waning moon in between the full and third quarter moon as well as in between the third quarter and new moon.

6. A lunar phase is the shape of the illuminated (sunlit) portion of the moon as seen by an observer on earth.  The lunar phases change cynically as the moon orbits the Earth, according to changing positions of the moon and sun relative to earth.  A lunar cycle is 29.53059 days and is the moon's full cycle.

Lunar cycle

     There are about 12 hours and 25 minutes in between two high tides.  Tides are the periodic rise and fallings of large bodies of water.  Winds and currents move the surface water and create waves.  The gravitational attraction of the moon causes the oceans to bulge out in the direction of the moon.

The moon affects Earth's tides.

Earth's Seasons/Eclipses
#RockinReview #eclipses

Nicolai Copernicus was the man that proposed that the sun, not the earth was at the center of the solar system.

We have seasons because the earth rotates on an axis that's tilted in its orbit.  That 23.5 degree tilt causes the different hemispheres to be at different angles to the sun at different times of the year.

In the winter, when the sun is closer to earth, is colder because the energy from the sun must travel through more of the atmosphere to reach earth. The sun's rays are concentrated over a larger area, so it is harder for it to heat up that whole area.

An eclipse is causes by the earth, sun, and moon aligning, so we can see it happen from earth.  We don't have lunar eclipses every month because these 3 objects don't align every month.                                                   Lunar Eclipse

Cause of Lunar Eclipse

                                                                   Solar Eclipse

Cause of Solar Eclipse

     We have day and night because Earth rotates.  It spins on its axis and about half of the time it faces the sun and about half of the time it faces away from the sun, creating day and night.

Day & Night

     An equinox is the time at which the sun crosses the celestial equator, when day and night are of equal length.  This happens twice a year on about September 22 and March 20

     A solstice is when the sun reaches its highest or lowest point in the sky at noon, marked by the longest and shortest days.  This happens twice a year and we call it the Summer Solstice and the Winter Solstice.

Tectonic Plates
#platetectonics

     Alfred Wegener was a German polar researcher, geophysicist, and meteorologist.  He is known for his achievements in meteorology, and as a pioneer of polar research, but is mainly known for his theory of continental drift.  He is also known for his idea that a supercontinent known as Pangaea existed on the earth millions of years ago.

A convergent boundary is an actively deforming region where two or more tectonic plates move toward one another and collide.

A divergent boundary is a linear feature that exists between two tectonic plates that are moving away from each other.

A transform boundary is a strike-slip fault occurring at the boundary between two plates of the earth's crust.  The plates slide past each other in opposite directions.

Three Types of Plate oundaries

Intruded in geology means to be forced or thrust into a preexisting formation.

A subduction zone is a collision of two tectonic plates.  When they meet, one may slide underneath the other, curving down into the mantle.

     The tectonic plate just off the coast of Washington is the Juan de Fuca plate.   In between the Juan de Fuca plate and the North American plate is a very long subduction zone.  The denser oceanic plate is subducting beneath the less dense continental plate offshore of British Columbia, Washington, and Oregon.  The North American plate moves in a general Southwest direction overriding the oceanic plate.  The Cascadia Subduction Zone is where the two plates meet.  As the Juan de Fuca plate subducted under the North American plate, it melted and magma intruded into the continental area to form the Cascade Arch.

Formation of the Cascades

Convection currents are circular movements of hot fluids rising and cold fluids sinking.  Whichever way the convection current is moving in the earth's mantle, is the way the tectonic plate will move as well.

Plates Moving due to Convection Currents

A rift zones is a feature of some volcanoes, especially shield volcanoes, where a linear series of fissures in the volcanic edifice allows lava to be erupted from the volcanoes flank, instead of from its summit.

Rift Zone

     The Channeled Scablands were created by the cataclysmic Missoula Floods that swept periodically across eastern Washington and down the Columbia River Plateau during the Pleistocene epoch.  The Pleistocene epoch was the most recent Ice Age.