Science Olympiad Dynamic Planet Practice Test

What are fissure vents?

1. Large holes created by violent eruptions

2. Linear volcanic vents with minimal explosive activity

3. Underground chambers filled with magma

4. Sandy areas with no volcanic activity

The correct answer is: Linear volcanic vents with minimal explosive activity

Fissure vents are characterized as linear volcanic openings where magma can escape from the interior of the Earth to the surface. These vents typically do not exhibit the violent explosive activity associated with larger volcanic eruptions. Instead, they allow for the more passive outflow of basaltic lava, which can create extensive lava flows. This tranquil eruption style is often tied to the formation of large, shield volcanoes and lava plateaus. Unlike large holes created by violent eruptions, fissure vents tend to be elongated cracks or fractures rather than large craters. Furthermore, while magma chambers do exist in volcanic systems, fissure vents themselves are not underground chambers; they provide a direct pathway for magma to reach the surface. As for sandy areas with no volcanic activity, this description does not relate to the concept of fissure vents at all, as these vents are inherently tied to volcanic processes. By understanding these characteristics, it becomes clear why linear volcanic vents with minimal explosive activity accurately describe fissure vents.