Transcript HOT SPOTS - Norwich High School

Convection Currents and
HOT SPOTS
Convection Current
• the hot mantle deep in Earth moves:
hot rock expands, decreasing its density and
begins to rise;
• Colder and/or denser rock sinks
• this causes the rigid tectonic plates on the
surface to move and cools the deep interior of
the planet
• Convection also happens in the outer core,
which also helps to cool the core and generate
the Earth’s magnetic field.
• http://www.youtube.com/watch?v=ryrXAG
Y1dmE&feature=related
• http://www.pbslearningmedia.org/resource/
nvdv.sci.earth.yellowvolc-1/volcanism-atyellowstone/
5:45 min
• http://www.pbslearningmedia.org/resource/
ess05.sci.ess.earthsys.hawaii/platetectonics-the-hawai699ian-archipelago/
- hotspot (4:36)
Problems with Theory
• HOT SPOTS
• Not associated with plate boundaries
• Plates move over areas of rising magma
(Mantle thermal plumes)
• Can infer direction of plate movement
• Older volcanoes the farther you are from
hot spot