1. Tides

2. Tides are the regular rise and fall of the water level. Tides are the regular rise and fall of the water level. The moon creates tides through the pull of its gravity. The moon creates tides through the pull of its gravity. The pull isn’t strong enough to affect the crust or other landforms, but it is enough to cause a noticeable bulge in the ocean. The pull isn’t strong enough to affect the crust or other landforms, but it is enough to cause a noticeable bulge in the ocean. The high-tide bulge always stays with the moon as it travels around Earth. The high-tide bulge always stays with the moon as it travels around Earth.

4. Seasons

5. Earth’s Tilt The tilt of Earth’s rotational axis and the Earth’s orbit around the sun work together to create the seasons. The tilt of Earth’s rotational axis and the Earth’s orbit around the sun work together to create the seasons. Earth’s constant tilt causes the two hemispheres to be exposed to different intensities of sunlight throughout the year. Earth’s constant tilt causes the two hemispheres to be exposed to different intensities of sunlight throughout the year.

6. Solstices During the summer solstice, the northern hemisphere gets more direct sunlight causing longer days. During the summer solstice, the northern hemisphere gets more direct sunlight causing longer days. At this time, the southern hemisphere gets the least direct sunlight. At this time, the southern hemisphere gets the least direct sunlight. During the winter solstice, the northern hemisphere gets the least direct sunlight, causing shorter days. During the winter solstice, the northern hemisphere gets the least direct sunlight, causing shorter days. At this time, the southern hemisphere gets the most direct sunlight. At this time, the southern hemisphere gets the most direct sunlight.

7. Equinoxes During the vernal & autumnal equinoxes, neither the north or south hemisphere is inclined toward the Sun. During the vernal & autumnal equinoxes, neither the north or south hemisphere is inclined toward the Sun. On the vernal (spring) equinox and the autumnal (fall) equinoxes, day and night are about the same length all over the world. On the vernal (spring) equinox and the autumnal (fall) equinoxes, day and night are about the same length all over the world.