Author Question: How do geologists determine the composition of Earth's interior? Why not examine it directly? ... (Read 78 times)

bobbysung

  • Hero Member
  • *****
  • Posts: 519
How do geologists determine the composition of Earth's interior? Why not examine it directly?
 
  What will be an ideal response?

Question 2

Approximately what percent of geologic time is represented by the Precambrian? Which period within the Phanerozoic eon represents the longest interval of time? How long is it?
 
  What will be an ideal response?



juiceman1987

  • Sr. Member
  • ****
  • Posts: 316
Answer to Question 1

Energy from earthquakes allows scientists to model its composition. The distance and temperatures are too great to penetrate deep into much of Earth's lithosphere, let alone the rest of the planet.

Answer to Question 2

3958 out of 4500 million years which is approximately 3958/4500 or 88; Cretaceous Period 145 -65 = 80 million years.



Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question


 

Did you know?

Certain chemicals, after ingestion, can be converted by the body into cyanide. Most of these chemicals have been removed from the market, but some old nail polish remover, solvents, and plastics manufacturing solutions can contain these substances.

Did you know?

Nearly all drugs pass into human breast milk. How often a drug is taken influences the amount of drug that will pass into the milk. Medications taken 30 to 60 minutes before breastfeeding are likely to be at peak blood levels when the baby is nursing.

Did you know?

Stroke kills people from all ethnic backgrounds, but the people at highest risk for fatal strokes are: black men, black women, Asian men, white men, and white women.

Did you know?

Asthma-like symptoms were first recorded about 3,500 years ago in Egypt. The first manuscript specifically written about asthma was in the year 1190, describing a condition characterized by sudden breathlessness. The treatments listed in this manuscript include chicken soup, herbs, and sexual abstinence.

Did you know?

When blood is deoxygenated and flowing back to the heart through the veins, it is dark reddish-blue in color. Blood in the arteries that is oxygenated and flowing out to the body is bright red. Whereas arterial blood comes out in spurts, venous blood flows.

For a complete list of videos, visit our video library