Objective: students will map the location of volcanoes and analyze lava patterns.
Bell Ringer- What land feature is found inland of a Subduction boundary?
Answer: volcanoes
http://www2.wwnorton.com/college/geo/egeo/flash/2_9.swf
Notes:
Andesitic- igneous rocks high in silica. Typically Felsic. Example rhyolite.
Basaltic – igneous rocks low in silica. Typically mafic. Example basalt.
Pass out lab “Subduction Zone Lab 3 Subduction zones and volcanoes”
Have students read introduction.
Do map only! Skip questions.
Show class sample of basalt and sample of ryolite.
Andesitic rocks (like ryolite) form volcanoes on the upper plate in a subduction
boundary.
Basaltic rocks (like basalt) form from mid ocean ridges (diverging plates)
When done, discuss the lab activity and review answers.
Demo Hot Spots
Volcano Slope
NotesShield volcanoes- gentle slope, basaltic lava
Stratovolcanoes – steep slopes, andesitic lavas
Finding slope
Trig anomic functions
Opposite / adjacent = tangent
Degrees = inverse of tangent
Show topo maps
Show Mauna Lao
http://www.terraserver-usa.com/image.aspx?T=2&S=17&Z=5&X=8&Y=84&W=3
Mt. St. Helens
http://www.terraserverusa.com/image.aspx?T=2&S=15&Z=10&X=87&Y=799&W=1&qs=%7cmt.+st.+helens
%7cwashington%7c
Students complete slope lab and answer questions
Watch if time
http://www.youtube.com/watch?v=7as7Ej_U6yU&feature=related
Exit bell ringer- Draw a subduction boundary in your notebook with a deep ocean
trench and a volcano on the land.
Answer: