If you have ever played an instrument or simply banged or hit any object you have dealt with harmonic resonance frequency. Everything on Earth and in the universe vibrates at a certain frequency, but the vibration of the Earth as a whole is a different matter.
Harmonic Resonance Frequency
Every object or material in the universe exists with a certain frequency of vibration. This is the frequency that resonates when that object is hit. It can be represented as a wave in which the lowest possible frequency is called fundamental frequency. Objects may also have series of frequencies because they are made up of a variety of materials.
Why do objects have frequencies?
Every piece of matter has a resonance frequency or series of frequencies because all matter is made up of atoms. Atoms are formed by electromagnetic waves that have a specific frequency. When these atoms form a larger piece of matter, the frequency of the electromagnetic waves is the frequency of that matter.
Frequency of the Earth
The Earth is made up of billions of different materials and objects, therefore it operates at a huge number of frequencies. Of the almost infinite numbers of atoms on Earth, most resonate at very different frequencies, meaning that the Earth's frequency would be basically impossible to pin down to an individual vibration.
Scientists do not know the the harmonic resonate frequency of the Earth because it contains a large series of frequencies. However, at some point the frequency might be calculated if it becomes possible to combine the vibrations of all the objects on Earth into one logical number.