Kettner's Science Class
Earth Science
By: Abby S.

Moon Phases

The Moon's Affect on Ocean Tides


Waxing Moon: The moon at any time after new moon and before full moon, so called because its illuminated area is increasing.

Waning Moon: The moon at any time after a  full moon and before new moon (so called because its illuminated area is decreasing).

Gibbous Moon: When the Moon is more than half full, but not quite fully illuminated, when you look at it from the perspective of Earth.

Crescent Moon: Part way between a half moon and a new moon, or between a new moon, and a half moon.

Moon Patterns:

Waxing moon: During the first week of a waxing moon, the moon keeps moving farther around, so more of the near side becomes lit. You see thicker crescents as the moon waxes, or grows. During the second week, you see more of the moon as it moves along its orbit. When the near side is more than half lit but not fully lit, the Moon is still waxing, so the phases during the second week are called waxing gibbous moons.

Waning moon: During the third week of the moon cycle, the whole near side of the moon appears lit. As the Moon continues around during the third week, less and less of the near side is in sunlight. The Moon seems to shrink, or wane, so these phases are called waning gibbous moons. While during the fourth week, the moon is only part lit, and the lit portion of the moon continues to shrink.

Lunar Cycle:

Definition: A lunar cycle refers to the moon's continuous orbit around the earth. As the moon orbits the Earth, its appearance changes and gives us an indication of the moon's progress in the cycle.

Length of Cycle: A lunar cycle lasts around 29.5 days, or around 1 month.  

Earth's Seasons/Eclipses


Nicolai Copernicus (1473-1543) radically changed our understanding of astronomy when he proposed that the sun, not Earth, was the center of the solar system. This led to our modern understanding of the relationship between the sun and Earth.

Why do we have seasons?

We experience 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. Because of the angle, during winter the energy from the sun must travel through more atmosphere to reach the poles. Also, the given amount of the sun's energy is spread over a larger area.

In winter, the sun is closer to Earth, why isn't it warmer?

At the same time that the Northern Hemisphere is entering summer, the South Pole is tilted away from the sun, and the Southern Hemisphere is starting to feel the cold of winter. The sun’s glancing rays are spread over a greater surface area and must travel through more of the atmosphere before reaching the earth. There are also fewer hours of daylight in a 24-hour period.

Lunar Eclipses:

There are not lunar eclipses every month because the Moon's orbit around Earth is slightly inclined with respect to the ecliptic, solar and lunar eclipses do not occur every month but only a few times per year.

Causes of Eclipses:

Day and Night:

We have day/night because the Earth rotates. It spins on its axis, which is an imaginary line passing through the North and South Poles. The Earth spins slowly all the time, but we don't feel any movement because it turns smoothly and at the same speed.


The time or date (twice each year) at which the sun crosses the celestial equator, when day and night are of equal length (about September 22 and March 20).


Either of the two times in the year, the summer solstice and the winter solstice, when the sun reaches its highest or lowest point in the sky at noon, marked by the longest and shortest days.

Plate Tectonics

Alfred Wegener:

Alfred Wegener was a German meteorologist and geophysicist who developed the first theory of continental drift and formulated the idea that a supercontinent known as Pangaea existed on the Earth millions of years ago. Contiental drift is the gradual movement of the continents across the earth's surface through geological time.

Convergent: coming closer together, especially in characteristics or ideas.

Divergent: tending to be different or develop in different directions.

Transform Boundaries: A transform boundary is where two of the floats - two tectonic plates - slide alongside each other. When this happens, the scraping of the two plates causes earthquakes.

Tectonic Plates and Washington:

The tectonic plate that is just off the coast of Washington is the Juan de Fuca Plate. The Explorer Plate broke off from the Juan de Fuca plate between 5 and 7 million years ago. As it did, the Cascade Arc resumed and the modern Cascade and Olympic Mountains began to rise.

Convection Currents:

Convection currents in the magma of earth's layers cause plate tectonics. Large convection currents in the aesthenosphere transfer heat to the surface, where plumes of less dense magma break apart the plates at the spreading centers, creating divergent plate boundaries.

Rift Zone:

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

Subduction Zone:

A subduction zone is the biggest smash-up on Earth, marking the collision between two of the planet's tectonic plates, the pieces of crust that slowly move across the surface over millions of years. When two tectonic plates meet, one may slide underneath the other, curving down into the mantle

Channeled Scablands:

The Channeled Scablands are a barren, relatively soil-free landscape in eastern Washington, scoured clean by a flood unleashed when a large glacial lake drained. They are a geologically unique erosional feature in the U.S. state of Washington.

Rocks and Roles

Sedimentary Rock:

Sedimentary rock is a rock that has formed from sediment deposited by water or air.
Example: Sandstone is an example of sedimentary rock.

Metamorphic Rock:

Metamorphic rock is denoting rock that has undergone transformation by heat, pressure, or other natural agencies.
Example: Gneiss is an example of metamorphic rock.

Igneous Rock:

Igneous rock is formed through the cooling and solidification of magma or lava.
Example: Granite is an example of igneous rock.


Stratification is a system or formation of layers, classes, or categories. Stratification is used to describe particular geological layers of rocks.

Stratification in a rock.


The age of landforms can be estimated by studying the number and thickness of rock layers, as well as fossils found within rock layers. These estimations can be made because the thickness of total sedimentary record is divided by average sedimentation rates

Rock Cycle:

Sedimentary Layers:

The geologic events that could have caused huge blocks of horizontal sedimentary layers to be tipped or older rock layers to be on top of younger rock were natural catastrophes, including earthquakes, volcanic eruptions, glaciers, floods, storms, tsunamis, and the impacts of asteroids.

Living Organisms:

Living organisms have shaped land forms in a variety of ways. Such as when they die and their skeletons/shells build up layers. They dig holes in the ground allowing water to run into the ground. They build dams creating lakes. The eat vegetation promoting erosion. They send roots into cracks that can break down mountains. Then there are all the things that humans do.

The Rock Cycle: