Source
Science World
Science World for grades 6–10 brings science to life with fascinating feature articles and hands-on activities that reinforce science concepts and help students build test-taking and critical-thinking skills.
Subscribe

Earthquake Questions And Answers

Q. How Many Fault Lines Are There In California?

A. There are too many fault lines to count. Once scientists thought there were only 4 or 5, but now they know there are collaterals, faults that branch off major fault lines. For example, the devastating Whittier earthquake of 1987 occurred along a fault line scientists didn't even know was there.

Q. What Causes Earthquakes?

A. Earthquakes are naturally occurring phenomena. Most are caused by the constant movement between the Earth's plates.Along the San Andreas Fault they are caused by the Pacific Plate sliding past the North American Plate. Sometimes, two plates catch and energy builds up. At a certain point, something has to give. In a sudden, violent jerk, the two plates grate against each other, sending shock waves through the earth. This is an earthquake.

Q. Will Northern California Have Another, More Powerful Quake?

A. Yes, there is a very good chance that within 50 years there will be another one. Here's why: When there is an earthquake, energy is released in one area along a fault, or crack in the Earth's crust. However, the energy continues to build in other areas. Energy keeps building up until eventually there is another earthquake elsewhere along the fault. Scientists monitor the energy with instruments they sink into the ground.

Q. What Are The Chances Of Another Big Quake In California In The Next 15-30 Years?

A. Scientists predict there is a 30 to 50 percent chance of another big earthquake north of Los Angeles in the next 15 to 30 years.

Q. How Can You Tell The Difference Between An Earthquake And Aftershocks?

A. The earthquake sends out the strongest shock waves. The aftershocks are what occur later and in the same place along the fault line. As time passes, the aftershocks become less strong. Scientist predicted that the aftershocks from the October 17, 1989, earthquake would continue for one to two years, though many may have been too small to feel.

Q. Are There Ways To Warn People An Earthquake Is About To Happen?

A. Scientists are looking for ways to predict the Big One, or at least to quickly get more accurate data about earthquakes. At the California Institute of Technology, scientists are investigating a system of instruments known as TERRAscope. This is a terrestrial telescope that will let researchers look into the earth. Scientists hope TERRAscope and other devices may make it possible someday to predict earthquakes.

 

 

February 23, 1990

  • Teacher Store
  • The Teacher Store  
    From Sea to Shining Sea: California

    From Sea to Shining Sea: California

    by Teresa Kennedy

    Read about California's history in this book containing color photographs, maps, and interesting text. Learn why thousands of people worldwide are attracted to this beautiful state.

    Series Information

    Take a tour of Tombstone, a drive along the Extraterrestrial Highway, or visit a colonial theme park in a state that's named for a Tudor queen. You'll find them all in the exciting series that celebrates the history and geography, people and culture, sights and cuisines that make each of America's 50 states unique — from sea to shining sea.

    $22.88 You save: 25%
    Hardcover Book | Grades 4-5
    Add To Cart
    Educators Only
    From Sea to Shining Sea: California
    Grades 4-5 $22.88
    Add To Cart
  • Teacher Store
  • The Teacher Store  
    Rookie Reader® Español—Geografía: California

    Rookie Reader® Español—Geografía: California

    by Sarah De Capua

    The Popular Rookie format expands its horizons to all corners of the globe! Readers of Rookie Read-About® Geography will take off on adventures to cities, states, nations, continents, and more. Includes fantastic introductions to maps and globes as tools by which to navigate.

    $4.46 You save: 25%
    Paperback Book | Grades PreK-2
    Add To Cart
    Educators Only
    Rookie Reader® Español—Geografía: California
    Grades PreK-2 $4.46
    Add To Cart
Privacy Policy
EMAIL THIS

* YOUR FIRST NAME ONLY

* FRIEND'S FIRST NAME ONLY

* FRIEND'S EMAIL ADDRESS

MESSAGE
Here's something interesting from Scholastic.com