170 likes | 276 Views
Plate Tectonics and Continental Drift Voc Set 2. Asthenosphere. the soft layer of the Earth on which pieces of the lithosphere move; flowing portion of the upper mantle. ???. Did you know?. The asthenosphere flows like a liquid b reaks like a solid
E N D
Asthenosphere • the soft layer of the Earth on which pieces of the lithosphere move; flowing portion of the upper mantle ???
Did you know? • The asthenosphere • flows like a liquid • breaks like a solid (sort of like molten glass, but MUCH hotter)
Did you know? • Temperatures in the asthenosphere: 1400-3000 degrees celsius (the surface of the Sun is about 5000 C)
Lithosphere • the outermost layer of the Earth, including the crust and uppermost, solid portion of the mantle
Did you know? • Lithosphere means “ball of stone” in Greek
Did you know? • The lithosphere is a very thin layer – only about 1000 km (620 miles) thick.
Ridge • a line or range of hills or mountains, or an elongated elevation on the ocean bottom
Did you know? • The mid-ocean ridges of the world are all connected to make one long mountain range? • It is about 60,000 km long – that’s 37,282 miles!
Trench • a long, steep-sided valley on the ocean floor that happens when one plate subducts under another
Did you know? • The oldest ocean floor crust is found at subduction zones, where old crust will be recycled back into magma.
Did you know? • Trenches are usually found near volcanic island arcs. • Examples:
Fault • a break in the Earth's crust where rocks will slide past each other
Did you know? • Fault lines are frequent sites of earthquakes.
Did you know? • Fault lines are frequent sites of earthquakes.
Rift Valley • a long, deep valley formed by two tectonic plates moving away from each other
Did you know? • Parts of the East African Rift Valley are called the “cradle of mankind.” • The remains of “Lucy,” an early hominid that lived 3.2 million years ago, were found there!