QUES . Consider the following: UPSC 2024
1 . Pyroclastic debris
2 . Ash and dust
3 . Nitrogen compounds
4 . Sulphur compounds
How many of the above are products of volcanic eruptions?
(a) Only one
(b) Only two
(c) Only three
(d) All four
Ans (d)
Must read: Products of volcanic eruptions
EXPLANATION:
Volcanic eruptions produce three types of materials: gas, lava, and fragmented debris called tephra (Pyroclastic materials).
The main component of volcanic gas emissions is water vapour, followed by carbon dioxide (CO2), sulphur dioxide (SO2), and hydrogen sulphide (H2S).
The ease with which lava flows and the structures it forms depend on how much silica and gas the lava contains. The more silica, the more polymerization (formation of long molecules) occurs, stiffening the lava. The stiffness of lava is described in terms of viscosity– lava that flows easily has low viscosity, and lava that is sticky and stiff has high viscosity.
Collectively, loose material thrown from a volcano is referred to as tephra. Individual fragments are referred to in general terms as pyroclasts, so sometimes tephra is also referred to as pyroclastic debris.
