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.
Lava Flows. The major eruptive product of Hawaiian volcanoes is lava. Lava flows can form during fountaining eruptions or they can well out of the ground with little or no pyroclastic activity. There are two major types of basaltic lava flow, ' a'a and pahoehoe.