Consider the following statements
1. Lava plains and shield volcanoes are formed by highly fluidic acidic lava while volcanic cones are a feature of viscous basic lava.
2. Volcanic eruptions in coastal regions or oceanic ridges could set up tsunami waves.
3. Mt. Vesuvius is known as the ‘lighthouse of the Mediterranean’.
Select the correct answer using the codes given below
Explanation:
Statement 1-Basic lavas are rich in basic oxides of iron, magnesium etc. and poor in Silica. They are highly fluidic and as a result spread out as thin sheets over large areas to form lava plains and basalt plateaus like the Deccan plateau. They also form vast Shield or Dome volcanoesmarked by gently sloping sides.
Acidic lavas are rich in silica and are highly viscous. As a result it solidifies rapidly after coming out of vent and accumulates in layers around the vent only forming steep sided cones. Due to rapid congealing of lava the vent often gets choked leading to explosive outburst of lava and formation of features like Calderas.
Statement 2- Mt. Krakatau in Indonesia erupted in 1883 creating tsunami waves that killed thousands of people.
Statement 3- Mt. Stromboli is known as the lighthouse of Mediterranean.