Author Question: How do geologists determine the composition of Earth's interior? Why not examine it directly? ... (Read 65 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?

Pope Sylvester II tried to introduce Arabic numbers into Europe between the years 999 and 1003, but their use did not catch on for a few more centuries, and Roman numerals continued to be the primary number system.

Did you know?

Amoebae are the simplest type of protozoans, and are characterized by a feeding and dividing trophozoite stage that moves by temporary extensions called pseudopodia or false feet.

Did you know?

About 600,000 particles of skin are shed every hour by each human. If you live to age 70 years, you have shed 105 pounds of dead skin.

Did you know?

GI conditions that will keep you out of the U.S. armed services include ulcers, varices, fistulas, esophagitis, gastritis, congenital abnormalities, inflammatory bowel disease, enteritis, colitis, proctitis, duodenal diverticula, malabsorption syndromes, hepatitis, cirrhosis, cysts, abscesses, pancreatitis, polyps, certain hemorrhoids, splenomegaly, hernias, recent abdominal surgery, GI bypass or stomach stapling, and artificial GI openings.

Did you know?

In 1886, William Bates reported on the discovery of a substance produced by the adrenal gland that turned out to be epinephrine (adrenaline). In 1904, this drug was first artificially synthesized by Friedrich Stolz.

For a complete list of videos, visit our video library