they arupt 2 a year
Never.
They don't. Few, if any volcanoes in the world do. The volcanoes, especially at subduction zones, will often go dormant for years and even centuries without erupting.
The frequency of volcanic eruptions varies depending on the volcano. Some volcanoes erupt frequently, while others may remain dormant for hundreds or thousands of years. It is difficult to predict exactly how many times a volcano will erupt in the future.
Active volcanoes are erupting or has erupted recently. Dormant volcanoes haven't been erupting recently, but may erupt in the future. They could be considered "sleeping". Extinct volcanoes will never erupt again.
Volcanoes supplied by subduction zones usually erupt due to buildup of pressure of these gases. This lava tends to erupt explosively as solid pieces of ash, cinders, bombs, etc. often filled with gas bubbles. Volcanoes supplied by deep mantle hotspots have almost no gas in their lava and erupt due to buildup of magma rising from the hotspot. This lava tends to erupt quietly as a fluid.
Yes, they often erupt again.
There are no volcanoes in the Grand Canyon.
Never.
every 2 years
Yes. Composite volcanoes often produce violent eruptions.
As many as it wants. Some volcanoes erupt often, some infrequently
At their early stage mostly during the youthful age.
Often volcanoes erupt throwing molten rock which is glowing hot if they are not just spouting smoke and ash.
Volcanoes eurpt more often in Mount St. Helen located in Washington in the U.S
They don't. Few, if any volcanoes in the world do. The volcanoes, especially at subduction zones, will often go dormant for years and even centuries without erupting.
Active volcanoes are those which are liable to erupt or have shown frequent eruptions within recent history.They are ones that still erupt at (irregular) intervals, often gently emitting gases and steam during their quiescent spells.
Sulphar Dioxide is the gas that volcanoes release. How much Iceland produces depends on how many and how often volcanoes erupt.