First off, let's look into how an earthquake happens:
As the plate move apart or collide given the convection current of magma, stress is built up with continuous plate movements. The pressure is then greater than the elastic strength of the rock. Rock breaks, the pressure of energy is released in the form of seismic waves. Ground vibrates, resulting in earthquake.
How it provide evidence about the layers of Earth, is that the lower the layer, the hotter it is, which then cause the convection current of magma to happen,hence affecting the lithosphere.
Hope it helps!
Seismic waves traveling through the earth<span> refract for the same reason that light refracts when entering different substances (e.g. air, water). The inner </span>core<span>has a different density from the outer </span>core<span>, and this difference in density </span>tells<span> us that it is </span>solid<span>.
Hope this helped. Good luck!
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Answer:
2. the line separating Australian animal species from non-Australian species
Explanation:
The Wallace line is an animal boundary line drawn by Alfred Wallace that separates Australian fauna species from non-Australian fauna species. It's a transitional zone between Austrialia and the Asia continent. The animals found in south East Asia is so much different from those found in Australia, hence the line drawn. The line is just one of the many biogeographical borders in the world separating geographical regions with not so similar group of plants and animals.
Answer: sugar
Explanation: it is one of the most valuable crops they have there
<span>The rock layers must have formed at different times because they contain two different biozones.
The rock layer containing the trilobites must have formed before the one containing the ammonites.
The key thing to note here is that the Trilobites only lived from 540 to 248 million years ago. And that the Ammonites were from 245 to 65 million years ago. So there's a 3 million year gap between these 2 different creatures where neither of them existed. So the dig where the trilobites were found has to be at least 3 million years older than the dig where the Ammonites were found. So with that in mind, let's look at the options and see what makes sense.
The rock layers must have formed at the same time because they both contain biozones.
* This is nonsense no matter what dates you're speaking of. In effect it claims that all rocks that indicate life were created at the same time. So this is definitely a bad choice.
The rock layers must have formed at different times because they contain two different biozones.
* This is technically incorrect since it assumes that all biozones represent an unique period of time which is incorrect. However, since the biozones represented by the presence of Trilobites and Ammonites don't overlap, it is true that these these rock layers were formed at different times. I would have preferred if this option said "non overlapping biozones". But on the balance, I'd consider this option to be true, so it should be selected.
The rock layer containing the trilobites must have formed before the one containing the ammonites.
* This is definitely true since the last Trilobite died about 3 million years before the first Ammonite lived. So this is a correct choice.
The rock layer containing the trilobites must have formed after the one containing the ammonites.
* This is the opposite of the previous option. And since the previous option was true, this option must be false. So this is a bad choice.</span>