What does the ancient earthquake detector do? it help tell the direction of where it came from and the slightest movement will make the ball fall if you are referring to the ancient china one Edit
Depending on the type of lava flow, the resulting rocks look very different. This was a pahoehoe flow. A lava flow is caused by a volcanic eruption. The lava can flow down the volcano at speeds ranging from 1/24 to 50 meters an hour. They can be 1,300 degrees fahrenheit or more. They are very destructive.
The two most important properties of lava are its viscosity, and the amount of gases dissolved in the liquid rock. Let's look at each of these separately. Viscosity is a term that describes the fluidity or runniness of the lava. Some lavas are very runny, not quite like water, but more like warm honey or hot wax.When these lavas erupt, they flow for large distances before cooling enough to turn solid.olcanic eruptions may be quiet outflows of lava which are so peaceful that one can stand close enough to toss in pebbles (or leis; see figure) or so explosively violent that they blow mountains apart and blast everything within a hundred miles to smithereens (not recommended for close observation).