Author Question: How do we know how to determine velocities of seismic waves in rocks? What will be an ideal ... (Read 36 times)

cagreen833

  • Hero Member
  • *****
  • Posts: 544
How do we know how to determine velocities of seismic waves in rocks?
 
  What will be an ideal response?

Question 2

How do earthquakes make images of Earth's interior?
 
  What will be an ideal response?



nital

  • Sr. Member
  • ****
  • Posts: 320
Answer to Question 1

Answer: Laboratory experiments relate seismic-wave velocities to different types of rocks, under temperature and pressure conditions comparable to those in the deep interior of Earth. Seismic waves move more slowly in unconsolidated sediment than through sedimentary rocks, and they move even faster in igneous and metamorphic rocks. Within igneous rocks, felsic rocks transmit waves more solely than mafic rocks, and ultramafic rocks display the most rapid velocities.

Answer to Question 2

Answer: Earthquakes produce surface waves and two distinct body waves, called primary (P) and secondary (S) waves, which travel through the planet. P and S waves reflect and refract when encountering boundaries between materials. Seismograms are records of earthquake waves detected by seismometers located around the globe. The time required for different earthquake waves to reach these instruments reveals the velocity at which the waves move through Earth. Travel-time curves reveal that, in general, seismic-wave velocity increases at deeper levels in the mantle. Shadow zones where S waves, P waves, or both are not recorded reveal that Earth has a liquid outer core, beginning at 2900 kilometers below the surface, surrounding a solid inner core at 5155-6371 kilometers depth.



Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
 

Did you know?

The toxic levels for lithium carbonate are close to the therapeutic levels. Signs of toxicity include fine hand tremor, polyuria, mild thirst, nausea, general discomfort, diarrhea, vomiting, drowsiness, muscular weakness, lack of coordination, ataxia, giddiness, tinnitus, and blurred vision.

Did you know?

If all the neurons in the human body were lined up, they would stretch more than 600 miles.

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?

The U.S. Pharmacopeia Medication Errors Reporting Program states that approximately 50% of all medication errors involve insulin.

Did you know?

Everyone has one nostril that is larger than the other.

For a complete list of videos, visit our video library