Earth Science: Current research

Me: Dr. Ziegler(or Dr. Z)

About me

0-18: Sioux Falls, SD 18-30: San Diego, CA

About me

What do these things have in common?

Becoming a Scientist1. Be very curious (and creative)2. Take Science and Math in High School3. Go to college 4. Go to graduate school to get a phD

Dr. Z:

Graduate School:

Working at OSU:

Teach me: Plate Tectonics

What questions have you asked?What have you learned?

Scientists today ask: what IS driving plate tectonics

•Convection•Slab Pull•Ridge Push

Short Story: heat trying to escape

5000 degrees!!

Seismic Tomography

Colder & Denser

Warmer & less dense

Scientists today ask: do plates sink all the way down?

What does Dr. Z ask?

Why and HOW does the magnetic field flip?How old is the inner core?What is going on where the mantle and the core meet?

Next time I’ll bring magnets!

Main field: Dipolar, 11o tiltCompass to geograph. north

Earth’s magnetic field

Caution: No actual bar magnet inside Earth

Really: Fluid motion in liquid outer iron core makes the magnetic field through ‘dynamo action’

Liquid!

Result: a dynamic magnetic field

Earth’s magnetic field

Two polarities, field occasionally ‘flips’ between them:

Normal Polarity

Reverse Polarity

Reversals in Earth’s past:

Field Excursions: *exact definition not agreed

upon

Are excursions and reversals related?

Paleomagnetism: study of

magnetization of old rocks

Volcanic RocksSediments

Working at OSU:

Leah’s Research: Magnetic field strength changes

Brunhes Matuyama OlduvaiJaramillo

Cobb Mountain

Mag

neti

c S

tren

gth

Today 2 Million years ago

Low at reversals

a.k.a. - what is that crazy core doing this time??

Strong

Weak