EARTHQUAKES

IN THE MIDWEST

Slideshow to Accompany NOVA scienceNOW Episode Aired 09.01.09 http://www.pbs.org/wgbh/nova/earth/earthquakes-midwest.html

The earth’s crust is made up of pieces called plates. When the plates move, they rub against each other. This causes the ground to shake.

THE EARTH IS LIKE A PUZZLE

Illinois is near the center of the United States. It is not near a plate boundary, yet it still gets earthquakes.

ILLINOIS

California is on the western edge of the United States. It lies along the North American plate boundary.

CALIFORNIA

Seismologists are Earth scientists who study earthquake and their energy waves.

They use seismometers to measure ground motion. The larger the line recorded, the more energy in the wave.

WHAT IS A

SEISMOGIST?

NEW MADRID MARKER

HOW DO YOU STUDY A 200 YEAR OLD EARTHQUAKE?

Scientists look for clues the earthquake left behind. The light patches in this aerial photo show old sand blows caused by earthquakes.

STALAGMITE

RINGS

OTHER EVIDENCE: SAND BLOWS

Why do you think geologists look at both stalagmitesand blow evidence? Isn’t one type of evidence good enough?

Geologists estimate the hazard of the New Madrid Seismic Zone is as high as California and Alaska.

U.S. EARTHQUAKE HAZARD MAP

The New Madrid Seismic Zone has several faults hidden beneath 100- to 200- foot thick layers of soft river soils.

UNDERGROUND

FAULTS

THE MIGHTY

MISSISSIPPI

The Mississippi Riverruns right through the New Madrid Seismic Zone.

Geologists estimate a 25-40% chance a significant New Madrid area earthquake will happen in the next 50 years.

WHEN IS THE NEXT BIG NEW MADRID

EARTHQUAKE?

PREDICTION OF

DAMAGE FROM A

LARGE NEW

MADRID

EARTHQUAKE

Check out these earthquake websites!

United States Geological Service Education Links http://earthquake.usgs.gov/learn/

Shake, Rattle and Slide

http://urbanext.illinois.edu/earth/

Facts About the New Madrid Seismic Zone http://www.dnr.mo.gov/geology/geosrv/geores/techbulletin1.htm

WANT TO LEARN MORE ABOUT EARTHQUAKES?

See how much you learned today. Click the link below to take the New Madrid Earthquake quiz.

https://qtrial.qualtrics.com/SE/?SID=SV_0fwqla08fgSswGF

NEW MADRID QUIZ