A lava plateau is a large, flat area of land created by lava filling in all the valleys and other depressions. Lava plateaus are created by low-viscosity basaltic magma, which spreads very quickly before it cools, allowing it to cover a large area.
Located in the northwestern United States, the Columbia Plateau is one of the world's largest lava plateaus. The lava flows creating this landform originated between 17 and 6 million years ago. Over 170,000 cubic kilometers of lava cover this region, and over 300 major lava flows contributed to its formation with vents measuring over 150 kilometers long.Learn More
The temperature of lava ranges from 700 degrees Celsius (1,292 degrees Fahrenheit) to 1,250 degrees Celsius (2,282 degrees Fahrenheit). The higher temperatures are reached in Hawaiian volcanoes.Full Answer >
Lava, or molten rock that erupts from volcanoes and fissures, is so hot because rock only melts at very high heat. Typically, only a small portion of any rock melts, even at depths of around 93 miles inside the Earth.Full Answer >
Most existing valleys have been formed by geological conditions that happened thousands of years ago. Rivers and streams are responsible for forming most of the modern valleys. The flowing waters cut valleys in "V" or "U" shapes, carving steep-walled sides and narrow floors. Other valleys have been made from large glaciers. The massive blocks of snow and ice slowly move downhill, leaving in their wake a hollowed-out valley.Full Answer >
Bridges and tunnels were important in eliminating the long way up and down in valleys and around mountains. Construction crews worked ahead of track-layers to build tunnels and bridges.Full Answer >