Question

how can you say that the earth is still active?​

Answer 1

Answer:

How can you say that the earth is still very active?

The evidence point to a simple mechanism: The bulk of the Earth’s volume is still hot, molten rock because of radioactive decay.

A few centuries back, a common explanation was that it was leftover heat from all the collisions that formed the Earth around 4 billion years ago. As geologists improved their knowledge of the planet’s structure, it was eventually shown that, while that hot origin with radiative cooling had happened, it would have cooled the planet’s interior completely within only a few million years. So they had to look for a different explanation for the current high temperature, and over the 20th century, they verified that the decay of leftover radioactive isotopes in the original planet easily explained it.

You can read about the most spectacular piece of evidence to support that conclusion at Natural nuclear fission reactor - Wikipedia, which describes the discovery of an area in Africa where (about 1.7 billion years ago) geological processes concentrated radioactive isotopes to the point that they formed a “reactor” that melted some large chunks of the uranium-rich deposits in one stratum.

Geologists are on the lookout for other similar deposits, but haven’t found them yet. They are reasonably sure that the isotopes are sufficiently depleted everywhere inside the planet that it can’t happen again. But the slow decay of all the radioactive isotopes is still happening at a level that keeps most of the Earth’s interior in a liquid state. It’s a very slow process. It’ll take a few billion more years before the decay level decreases to the point that the planet will be solid throughout.

Explanation:

Answer 2

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Que. how can you say that the earth is still active?

Ans. We can say earth is still very active. Because the matter from deep inside the mantle shoots up through volcanoes and fissures on the ocean floors and cools down to form the earths crust. In many regions on the earth, part of the earths crust enters into and once again become molten.

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