Compressional or P (for primary)
, Transverse or S (for secondary)
, Love, and Rayleigh. Primary waves push and pull the ground in the direction the wave is traveling. Secondary waves travel in the same direction, but they shake the ground back and forth perpendicular to the direction the wave is traveling. Love waves move back and forth horizontally. Rayleigh waves cause both vertical and horizontal ground motion.
The languages they speak and the holidays they celebrate
Differences between the Troposphere and the Stratosphere:
The troposphere is the lowest level of the atmosphere, so it is in contact with the Earth’s surface. In contrast, the stratosphere is located above the troposphere, so it is not in contact with the Earth’s surface. Humans live in the troposphere, not the stratosphere. People only spend time in the stratosphere is when they are traveling through it on an airplane, or flying through it while riding in a rocket. The air density and air pressure are much lower in the stratosphere. In fact, stratospheric air is too thin for people to be able to survive without pressurized air to breathe.
