I think the answer is "the older it is"
Reason: I might be wrong but is something (like a shell) gets buried in something (like sand), overtime many things (like dirt, soil, sand, etc.) will be on top of the original. This will make layers. So, the older rock is on the bottom since it has been there for the longest and it gets covered by other stuff (causing the layers).
Hope this helps! :) (If I'm wrong, sorry :( )
Answer:
The greenhouse effect is a natural process that warms the Earth's surface. When the Sun's energy reaches the Earth's atmosphere, some of it is reflected back to space and the rest is absorbed and re-radiated by greenhouse gases. ... The absorbed energy warms the atmosphere and the surface of the Earth.
Why Earth's inner core<span> has speed trap for </span>seismic waves<span>. </span>Earth<span> has multiple layers: the crust, the mantle, the liquid </span>outer core<span> and the </span>solid inner core<span>. Something is not quite right inside the </span>Earth's core<span>. When </span>seismic waves<span> from earthquakes ripple through its </span>solid<span> center, they hit a speed bump.</span>
