6. Earth’s layers have different properties. 6-70 km thick 0-700 °C Cooler rock Crust 2900 km thick 870-4400 °C heated rock Mantle 2300 km thick 4400-6100 °C liquid metals Outer Core 2400 km diameter 7000-8000°C solid metals Inner Core Thickness Temperature Composition Layer Earth’s Layers
26. These magnetic reversals are caused by changes in Earth’s magnetic fields. Bands of rock record periods of magnetic reversals. As molten material cools, magnetic minerals line up with the magnetic field. When it hardens, the minerals act like tiny compass needles. See Page 24
30. The Hawaiian islands are located in the middle of the Pacific Plate. The largest island, Hawaii, is still over the hot spot.
31. When the plate moves on, it carries the first volcano away from the hot spot. Heat from the mantle plume will then melt the rock at a new site, forming a new volcano. See Page 28
33. Tectonic plates push together and form three types of convergent boundaries. Continental-continental collision: Two continental plates collide, crumpling and folding the rock between them. Mountains could form.
34. Continued Oceanic-oceanic subductions: two oceanic plates collide and the older, denser plate sinks beneath the top plate, forming deep-ocean trenches and island arcs.