and what kind of material does the second one eject?
It ejects  Pumice
Pumice
Pumice (), called pumicite in its powdered or dust form, is a volcanic rock that consists of highly vesicular rough textured volcanic glass, which may or may not contain crystals. It is typically light colored. Scoria is another vesicular volcanic rock that differs from pumice in having larger vesicles, thicker vesicle walls and being dark colored and denser.
what type of eruption does nevado del ruiz produce The volcano usually generates Vulcanian to Plinian eruptions can you explain the first one? It is a type of volcanic eruption characterized by a dense cloud of ash-laden gas exploding from the crater and rising high above the peak
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Pumice [SEP] Introduction
Pumice (), called pumicite in its powdered or dust form, is a volcanic rock that consists of highly vesicular rough textured volcanic glass, which may or may not contain crystals. It is typically light colored. Scoria is another vesicular volcanic rock that differs from pumice in having larger vesicles, thicker vesicle walls and being dark colored and denser. Pumice is created when super-heated, highly pressurized rock is violently ejected from a volcano. The unusual foamy configuration of pumice happens because of simultaneous rapid cooling and rapid depressurization. The depressurization creates bubbles by lowering the solubility of gases (including water and CO) that are dissolved in the lava, causing the gases to rapidly exsolve (like the bubbles of CO that appear when a carbonated drink is opened).