Author Question: You're still on the ship and yesterday your compass needle pointed north, and it was also pointed up ... (Read 69 times)

armygirl · **on:** Jul 16, 2018

You're still on the ship and yesterday your compass needle pointed north, and it was also pointed up at 10 degrees. Today, your compass needle is pointed north and down at 10 degrees. What part of Earth did you sail from during this time?

Explain how you know.
What will be an ideal response?

Question 2

You measure the magnetization in a 100 million-year-old rock from North America. The magnetic minerals you measure have an inclination that is much shallower (lower inclination) than North America has today. From this measurement you conclude:

a. that North America has moved closer to the equator in the last 100 million years.
b. that North America has moved farther from the equator in the last 100 million years.
c. that North America was uplifted 100 million years ago.
d. that North America has moved both west and south in the last 100 million years.
e. that plate tectonics is wrong and that continents don't move.

TDubDCFL · **Reply #1 on:** Jul 16, 2018

Answer to Question 1

You sailed across the equator from the Southern Hemisphere (needle pointed up) into the Northern Hemisphere (needle pointed down).

Answer to Question 2

b. that North America has moved farther from the equator in the last 100 million years.