enhanced science 1-4

• Shield Volcanoes

  formed by the accumulation of lava that oozes out from the volcano.

  
• Cinder Cones

  built from ejected lava fragments. They

  have a steep slope, wide crater and are

  the most abundant of the three major volcano types

  
• Composite cones or stratovolcanoes

  large, nearly perfect sloped structure formed from alternate solidification of

  both lava and pyroclastic deposits.

  
• Viscosity

  the property of the material's resistance to flow.
• Higher silica content means

  higher viscosity (viscosity increases with increasing silicon concentration in the magma)
• Lower temperature magmas have

  higher viscosity than higher temperature magmas (viscosity decreases with increasing temperature of the magma)
• High Viscosity

  thicker and slow moving magma
• Low Viscosity

  thinner and fa st moving magma
• Phreatic or hydrothermal

  is a stream driven eruption as the hot rocks come in contact with water. It is short-lived,

  characterized by ash columns but may be an

  onset of a larger eruption

  
• Phreatomagmatic

  is a violent eruption due to

  the contact between water and magma. As a

  result, a large column of very fine ash and high speed and sideway emission of pyroclastics

  called base surges are observed.

  
• Strombolian

  a periodic weak to violent

  eruption characterized by fountain lava,

  
• Vulcanian

  eruption is a stronger than strombolian characterized by tall eruption columns that reach up to 20 km high with

  pyroclastic flow and ashfall tephra

  
• Plinian

  largest and most violent - excessively explosive type of

  eruption of gas and pyroclastics

  
• Magma

  molten rock beneath earth's surface

  
• Parasitic cone

  a small cone-shaped volcano formed by an accumulation of volcanic debris

  
• Sill

  a flat piece of rock formed when magma hardens in a crack in a volcano

  
• Vent

  an opening in earth's surface through which volcanic materials escape

  
• Flank

  the side of a volcano

  
• Lava

  molten rock that erupts from a volcano that solidifies as it cools

  
• Crater

  mouth of a volcano - surrounds a volcanic vent

  
• Conduit

  an underground passage magma travels through

  
• Summit

  highest point; apex

  
• Throat

  entrance of a volcano. The part of the conduit that ejects lava and volcanic ash.

  
• Ash

  fragments of lava or rock smaller than 2mm in size that are blasted into the air by volcanic explosions.

  
• Ash Cloud

  a cloud of ash by volcanic explosions

  
• Volcano

  these are natural openings in the earth's surface where molten rocks, smoke, gases, and ashes are ejected.
• Caldera

  a volcanic crater that is formed when a part of the wall of the crater collapses following an explosive eruption
• Hot_Spot

  a heat source deep within the mantle, 100-200 km across, and persistent for millions of years ex. Yellowstone National Park and the Hawaiian Islands
• Active

  a volcano that has had at least one record of eruption during the past 10,000 years
• Plate Tectonics

  this is where volcanoes circuit
• Olympus Mons

  the largest volcano on Mars and the largest in the solar system ; 72,000 feet tall
• Tamu Massif

  most massive volcano
• Mauna Kea

  tallest volcano on Earth
• Ojos del Salado

  highest volcano
• Mt. Kanlaon

  Philippine's largest active volcano
• Very hot magma

  low viscosity
• Cool magma

  high viscosity
• High viscosity (gases)

  more gas build up= more violent eruption
• Low viscosity(gases)

  less gas build up= less violent eruption
• Effusive

  quiet or nonexplosive eruption, most common type of eruption, produces calm lava flow, releases huge amount of lava but less ash and dust