Opening of Earth's Surface: The Vent

Vents are the locations from which lava flows and pyroclastic material are erupted. Their forms and orientations can be used to determine many characteristics of the eruption with which they were associated. A volcanic vent is that spot in the Earth’s crust where gases, molten rock, lava and rocks erupt. Volcanic vents can be at the top of some of the largest volcanoes on Earth, like Hawaii’s Mauna Kea, or they can be openings in the Earth’s crust down at the bottom of the ocean. The shape of the volcanic vent can sometimes define whether the volcano is explosive or not. A fissure vent can be a few meters wide and many kilometers long. Lava pours out of fissure vents, creating lava channels, but they don’t usually explode.

• Main vent is the main outlet for the magma to escape.

• Secondary vents are smaller outlets through which magma escapes.

Types of Vents

Central Vents are the most common types of volcanic vents. Central vents are the conduit pipes through which magma is forced upward to the surface of the Earth, and then ejected as gases, lava or pyroclastic fragments. A central vent connects the magma chamber to the open vent on top of a volcano, and is maintained open by the continuous release of volcanic material. A central vent sometimes can be enlarged by the collapse of its peripheral walls. Eruptions may also occur through fissures made in the volcanic conduit pipe and flowing out through a linear vent on the side of a shield volcano.

Hydrothermal Vents are often associated with undersea volcanoes. This is because the vents are created and sustained by the heat of volcanic activity at tectonic plate boundaries, found throughout the globe. Down in the deep and dark waters, they found hot springs on the ocean floor releasing warm and mineral-rich fluids – these are called hydrothermal vents. At these locations, seawater seeps through cracks in the seafloor and is heated by molten rock. This causes chemical reactions between the two, and the altered seawater becomes hydrothermal fluid. This hot fluid then jets back into the ocean, forming a hydrothermal vent.

References: http://volcano.oregonstate.edu/vents https://volcanoes.usgs.gov/volcanoes/kilauea/archive/multimedia/2006/Jul/main.shtml http://www.bbc.co.uk/schools/gcsebitesize/geography/natural_hazards/volcanoes_rev2.shtml https://www.universetoday.com/29568/volcanic-vent/ https://oceantoday.noaa.gov/underwatervolcanoes/ https://oceanservice.noaa.gov/facts/vents.html https://owlcation.com/stem/Types-of-Volcanic-Vents