Answer:
Scientists use waves to study the different layers of the earth. Usually, they use seismic waves, which are waves generated by earthquakes or nuclear-test explosions. So, scientists study the path and speed of these waves through the earth to decipher boundaries and the materials that make up the layers.
Explanation:
Answer:Fossil records
Explanation: fossil records are records which contains or provides proofs of the existence of man and the level of evolution which has taking place millions of years ago. Fossil record are archeological records which are obtained from the layers and strata of rocks, archeological records such as fossil records tend to contain components of the organic materials or organic make up of early,primitive or ancestral organisms though which study is conducted to determine diversity and evolution.
Out of all of those I would say tides, water wind and sunlight is located in all regions of the world so in my opinion tides seem like the most scarce source. Hope this helps
