Speed of the North American Tectonic Plate

Use the map on the previous page to figure out how fast the North American plate has
been moving since the first (oldest) volcano formed over the hotspot.

The questions below will guide you through the process.

1) How old is the oldest volcano in the system? (The ages on the map are millions of
years, Ma). __________ Ma
Take a piece of paper, hold it up to map scale against your screen on the bottom of the
map and make two tick marks on either end of the scale. Now you can move that scale on
your paper over your screen to measure distances.
2) How far is the oldest volcano from the hotspot? (use the north eastern edge of the
yellow volcano as the location of the hotspot) _____________ km
3) Now divide your answer for #2 by your answer for #1. ___________ Km/Ma
4) Now convert #s into cm/yr. If you’re not clear how to do this read the directions
above the map on the previous page __________cm/yr.
Direction of the North American Tectonic Plate
When tectonic plates move over hotspots the direction the plate is moving is from the
younger rock toward the older rock. In other words, if you draw an arrow on the map from
the younger rock toward the older rock that arrow points in the direction the plate is
moving.
5) Given what you know about how plates move over hot spots, what general direction
has the North American plate been moving for the last 16 million years?
______________
6) Was it moving in a straight line? __________

7) What direction was the plate moving between 13 and 16.1 million years ago?
__________
8) What direction has it been moving for the last 6.4 million years? ______________
(after doing #7 and #8 you may want to look at your answer for #6 and make sure
it still makes sense)
9) The Hawaii hotspot produces mafic volcanoes while the Yellowstone hot spot
produces felsic volcanoes, what does this mean for the relative explosiveness of
these two volcanoes ie which would be more and which would be less explosive?
10) Looking at question 9 what is is about the chemical composition that makes one
volcano more explosive? Relate the chemical composition of the volcano to the type
of crust involved.
11) Go to the website for the Yellowstone Volcano Observatory
https://www.usgs.gov/observatories/yellowstone-volcano-observatory
Do a screen capture of the current status of the Yellowstone volcano. I have an
example below from when I wrote this lab. This is a great site to go to when you see
that click bait article on Facebook about how Yellowstone is about to erupt and
destroy us all. If they YVO people aren’t worried, you need not worry either.
Remember please put your screen capture on your answer sheet not this worksheet

Question

Speed of the North American Tectonic Plate

Use the map on the previous page to figure out how fast the North American plate has
been moving since the first (oldest) volcano formed over the hotspot.

The questions below will guide you through the process.

1) How old is the oldest volcano in the system? (The ages on the map are millions of
years, Ma). __________ Ma
Take a piece of paper, hold it up to map scale against your screen on the bottom of the
map and make two tick marks on either end of the scale. Now you can move that scale on
your paper over your screen to measure distances.
2) How far is the oldest volcano from the hotspot? (use the north eastern edge of the
yellow volcano as the location of the hotspot) _____________ km
3) Now divide your answer for #2 by your answer for #1. ___________ Km/Ma
4) Now convert #s into cm/yr. If you’re not clear how to do this read the directions
above the map on the previous page __________cm/yr.
Direction of the North American Tectonic Plate
When tectonic plates move over hotspots the direction the plate is moving is from the
younger rock toward the older rock. In other words, if you draw an arrow on the map from
the younger rock toward the older rock that arrow points in the direction the plate is
moving.
5) Given what you know about how plates move over hot spots, what general direction
has the North American plate been moving for the last 16 million years?
______________
6) Was it moving in a straight line? __________

7) What direction was the plate moving between 13 and 16.1 million years ago?
__________
8) What direction has it been moving for the last 6.4 million years? ______________
(after doing #7 and #8 you may want to look at your answer for #6 and make sure
it still makes sense)
9) The Hawaii hotspot produces mafic volcanoes while the Yellowstone hot spot
produces felsic volcanoes, what does this mean for the relative explosiveness of
these two volcanoes ie which would be more and which would be less explosive?
10) Looking at question 9 what is is about the chemical composition that makes one
volcano more explosive? Relate the chemical composition of the volcano to the type
of crust involved.
11) Go to the website for the Yellowstone Volcano Observatory
https://www.usgs.gov/observatories/yellowstone-volcano-observatory
Do a screen capture of the current status of the Yellowstone volcano. I have an
example below from when I wrote this lab. This is a great site to go to when you see
that click bait article on Facebook about how Yellowstone is about to erupt and
destroy us all. If they YVO people aren’t worried, you need not worry either.
Remember please put your screen capture on your answer sheet not this worksheet

Accepted Answer

Plates are made up of from lithosphere. Lithosphere are about 100 km thick, they float on…

5015 16.1 15-13, N dano 12-10 10-7 6.4-4.3 10-7 0.6-2.1 Pocatell Yellowstone Hotspot Trace 100 km