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.
  Basaltic magma is low in silica and rich in iron and magnesium. It  is denser, more fluid, and hotte â¦ r than most other types of magma.  Because of its generally low gas content, volcanic eruptions  involving it are typically non-explosive or only mildly explosive,  often resulting in rivers of red hot lava.It is less dense, more viscous, and cooler than most other types of  magma. It usually has a very high gas content, meaning that most  eruptions involving it will be highly explosive. Most  supervolcanoes are fed by rhyolitic magma.